Diagnostic and surgical treatment for traumatic bile peritonitis in dogs and cats

OBJECTIVE

To describe short-term outcomes of dogs and cats undergoing surgery for traumatic bile peritonitis.

ANIMALS

13 dogs and 4 cats.

METHODS

Multi-institutional, retrospective study. Medical records from 6 institutions were reviewed for cases of traumatic bile peritonitis between 2006 and 2022. Clinical presentation, additional injuries, surgical treatment, and outcome were recorded.

RESULTS

Trauma occurred a median of 2 (range, 1 to 22) and 4 (range, 1 to 22) days prior to presentation in dogs and cats, respectively. Total bilirubin was increased in 11 of 13 dogs and 2 of 4 cats. Rupture occurred at the common bile duct (CBD) in 10 dogs and 1 cat, gallbladder in 3 dogs, cystic duct in 2 cats, and hepatic duct in 1 dog and 1 cat. The most common surgeries were cholecystoduodenostomy and CBD repair in dogs and cholecystectomy in cats. Eleven of 13 dogs and all cats survived to hospital discharge (88.2% overall survival). Median follow-up in surviving dogs and cats was 35 days (range, 14 to 401) and 30 days (range, 14 to 90), respectively. One dog that underwent cholecystectomy experienced recurrent bile peritonitis 20 days postoperatively. Short-term survival following surgical treatment of traumatic bile peritonitis was excellent and recurrence appears uncommon. The most frequent site of rupture was the CBD in dogs and the cystic duct in cats.

CLINICAL RELEVANCE

Measurement of peritoneal bilirubin should be considered in dogs and cats with peritoneal effusion following trauma. Surgeons should be prepared to identify and address ruptures in locations other than the gallbladder.

Treatment of retroperitoneal sarcoma results in improved outcomes

OBJECTIVE

To report the clinical characteristics, treatments, and outcomes in a cohort of dogs with histologically confirmed retroperitoneal sarcoma (RPS) and to identify potential variables of prognostic significance.

ANIMALS

46 client-owned dogs from 10 clinics with histopathologic diagnosis of a sarcoma originating from the retroperitoneal space.

METHODS

Medical records were retrospectively reviewed to obtain information regarding clinical characteristics, treatments, and outcomes. Recorded variables were analyzed to report descriptive data for all cases and overall survival time. Multivariate analysis was utilized to evaluate prognostic factors for overall survival.

RESULTS

Hemangiosarcoma was the most common histologic subtype diagnosed (76.1%). Cytoreductive and curative intent surgical excision of the RPS was attempted in 12 and 22 dogs, respectively; 12 dogs underwent no surgery or had an exploratory laparotomy with incisional biopsy only. Nineteen dogs received adjuvant chemotherapy, either injectable or metronomic, and 1 dog received adjuvant radiation therapy. Fourteen of the 34 (41.2%) surgically treated dogs developed evidence of local recurrence, but there was no difference in local recurrence when comparing dogs categorized as curative intent versus cytoreductive surgery. The median overall survival time was 238 days. On multivariable analysis, treatment approach was associated with survival with surgical excision (vs palliative treatment) and adjuvant chemotherapy following surgery being protective against death. A diagnosis of hemangiosarcoma was associated with a greater hazard of death.

CLINICAL RELEVANCE

This study demonstrates a substantially greater survival time than previously published and suggests a survival benefit from surgical excision and adjuvant chemotherapy.

Bupivacaine liposomal injectable suspension does not provide improved pain control in dogs undergoing abdominal surgery

OBJECTIVE

To evaluate the difference in postoperative pain scores of dogs undergoing abdominal surgery receiving surgical incision infiltration of saline or bupivacaine liposomal injectable suspension (BLIS).

ANIMALS

40 dogs undergoing exploratory laparotomy.

METHODS

Dogs were prospectively enrolled and randomized to receive either BLIS or saline surgical incision infiltration. All dogs received 5.3 mg of BLIS/kg or an equal volume of saline infiltrated in the muscle/fascia, subcutaneous tissue, and intradermal layer during closure. All dogs received a standardized postoperative pain management protocol. Pain assessment was performed at select time points postoperatively by blinded observers with an electronic algometer, short version of the Glasgow Composite Measure Pain Scale (GCMPS), and indirect measures of pain, including systolic blood pressure, heart rate, and serum cortisol levels.

RESULTS

At day 0, blood pressure was higher in the saline group (149.6 vs 125.8 mm Hg; P = .006). At day 3, GCMPS was lower in the BLIS group (BLIS = 1, saline = 2, P = .027), though both average GCMPS scores were low and only 10 dogs were available for day 3 assessments (6 BLIS and 4 saline). No other differences in algometer readings, GCMPS scores, other measured parameters, or need for rescue analgesia were present between BLIS and saline groups at any time point. There was no difference in postoperative incisional infection rate or complications.

CLINICAL RELEVANCE

Use of BLIS for exploratory laparotomy did not provide improved pain control over postoperative opioid administration alone. Patients that received BLIS had no increase in short-term complications.

Perioperative ventricular arrhythmias are increased with hemoperitoneum and are associated with increased mortality in dogs undergoing splenectomy for splenic masses

OBJECTIVE

To identify risk factors for intra- and postoperative ventricular arrhythmias (VAs) and in-hospital mortality in dogs undergoing splenectomy for splenic masses.

ANIMALS

308 dogs.

METHODS

Records from 2010 through 2018 were reviewed for dogs undergoing splenectomy for a splenic mass. Clinical and laboratory findings on admission, diagnostic imaging, anesthesia, surgery and pathology reports, treatment records, and in-hospital mortality were evaluated with logistic regression.

RESULTS

VAs occurred in 138 (44.8%) dogs (126/308 [40.9%] postoperative, 51/308 [16.6%] intraoperative, 26/308 [8.4%] preoperative), with 50/308 (16.2%) dogs having more than one type of VA. Increasing heart rate and body weight, decreasing PCV and platelet count, hemoperitoneum, receipt of a transfusion, and diagnosis of hemangiosarcoma were associated with the presence of intra- and postoperative VAs on univariable analysis (all P < .001). On multivariable analysis, hemoperitoneum (P < .001 , < .001), increasing body weight (P = .026, < .001), and increasing heart rate (P = .028, < .001) were significant for intra- and postoperative VAs, respectively. Twenty dogs died (20/308 [6.5%]; 14/138 [10.1%] with VAs, 6/170 [3.5%] without VAs). Intra- and postoperative VAs were associated with in-hospital mortality (P = .009, .025, respectively).

CLINICAL RELEVANCE

Perioperative VAs were common and odds of VAs were increased with hemoperitoneum, increasing heart rate, and increasing body weight. Presence of VAs increased the odds of in-hospital mortality. Despite this, the overall in-hospital mortality rate was low (6.5%), indicating a good prognosis for survival of surgery in dogs with splenic masses, regardless of the presence of VAs or hemoperitoneum.

Acute kidney injury is common in dogs with septic peritonitis and is associated with increased mortality

OBJECTIVE

To identify the frequency of and risk factors for acute kidney injury (AKI) in dogs undergoing abdominal surgery for septic peritonitis, and to evaluate outcome and kidney-related risk factors for survival to discharge in those dogs.

ANIMALS

77 dogs that underwent abdominal surgery for septic peritonitis.

METHODS

Medical records of dogs that underwent surgery for septic peritonitis from 2012 through 2022 were reviewed. Data regarding signalment, clinical and biochemical findings at presentation, blood creatinine concentration throughout hospitalization, surgery characteristics, postoperative monitoring, and outcome were collected. Dogs were classified based on occurrence of AKI and whether they presented with or developed AKI in-hospital. Perioperative risk factors were evaluated, and outcomes were compared with univariable logistic regression.

RESULTS

31 dogs (40.3%) had AKI diagnosed; 18/77 (23.4%) dogs presented with AKI, 11 (61.1%) of which had it postoperatively, and 13/77 (16.9%) dogs developed AKI postoperatively. Significant factors for presenting with AKI included increasing baseline respiratory rate (OR 2.5 for every 10 beats per minute higher), decreasing systolic blood pressure (OR 0.8 for every 10 mm Hg higher), and increasing body condition score (OR 2.2 for every score greater). No significant factors for developing AKI postoperatively were identified after multiple comparisons adjustment. Sixteen dogs (20.8%) did not survive to discharge; 12 (75.0%) had AKI and 4 (25.0%) did not. Dogs with AKI had decreased odds of survival to discharge (OR 0.2).

CLINICAL RELEVANCE

AKI was common in dogs with septic peritonitis and was a significant risk factor for survival to discharge. Clinical surveillance of AKI is critical in this population.

Accuracy, precision, and interobserver and intraobserver agreements related to pressure-measurement devices

OBJECTIVE

To evaluate the accuracy, precision, and observer agreement of three pressure measurement devices.

STUDY DESIGN

In vitro model study.

SAMPLE POPULATION

Water manometer with built-in gauge (WMg), arterial pressure transducer (APT), and Compass CT (CCT).

METHODS

The model was set to five predetermined pressures (4, 8, 13, 17, and 24 cm H2 O) using a water manometer with a ruler (WMr) as the gold standard. Each device was tested at each pressure in a randomized order by three investigators. Bland-Altman plots were used to assess agreement between devices. Intraclass correlation coefficients (ICC) were calculated for interobserver and intraobserver agreements.

RESULTS

The mean differences (cm H2 O) ± SEM in comparison with the set pressure were -0.020 ± 0.010 (WMg), -0.390 ± 0.077 (APT), and -1.267 ± 0.213 (CCT). Pressures measured by WMg did not differ from those measured by WMr. Pressures measured by all devices did not differ from each other (p > .062 for all comparisons). Interobserver agreement was excellent (1.000), and intraobserver agreement was excellent (0.985, 0.990, 0.998 for each observer).

CONCLUSION

Compared to the WMr, the WMg was the most accurate and precise, followed by the APT; the CCT was the least accurate and precise. Interobserver and intraobserver agreements for all three devices were excellent.

CLINICAL SIGNIFICANCE

The largest mean difference of all devices was within 1.3 cm H2 O of the set pressure, indicating possible clinical utility of any of the devices. However, WMr or WMg should be considered first due to their high precision and accuracy.

Staphylectomy in nonbrachycephalic dogs: A retrospective study of 27 cases

Objective

To report the outcomes and complications associated with staphylectomy in nonbrachycephalic dogs.

Animal

Twenty-seven nonbrachycephalic dogs with elongated soft palates and undergoing staphylectomy.

Procedure

Retrospective study.

Results

Increased upper airway noise (70.4%) and dyspnea (44.4%) were the most common presenting clinical signs. Concurrent upper airway abnormalities found in the study population included laryngeal collapse (25.9%) and laryngeal paralysis (14.8%). The most common staphylectomy technique used in this study was sharp excision (66.7%) with sutured oral and nasal mucosal apposition. The dogs in this study had an overall minor postoperative complication rate of 33.3%, with regurgitation/vomiting (11.1%) and coughing (11.1%) occurring most commonly. No dog required supplemental oxygen therapy or temporary tracheostomy.

Conclusion

Staphylectomy was well-tolerated in nonbrachycephalic dogs and was associated with a relatively low rate of complications. Concurrent airway abnormalities were common among nonbrachycephalic dogs with elongated soft palates, similar to brachycephalic dogs.

Clinical relevance

Clinicians should be aware that elongated soft palate can occur in nonbrachycephalic dogs, and surgical correction can be achieved with rare major or catastrophic complications.

Retrospective evaluation of surgical treatment of linear and discrete gastrointestinal foreign bodies in cats: 2009-2021

OBJECTIVES

Gastrointestinal foreign bodies (FBs) are an important cause of emergency surgical intervention in cats, but little information exists in the literature evaluating the risks and outcomes in this species. The study purpose was to describe cases of feline FBs and compare perioperative factors and outcomes between linear foreign body (LFB) and discrete foreign body (DFB) surgery in cats.

METHODS

The medical records from the University of Georgia Veterinary Teaching Hospital were searched for cats that had undergone surgery for FB removal between August 2009 and August 2021. Perioperative data were collected and described. Data were compared between cats with an LFB and cats with a DFB. A binomial probability series was used to estimate the likelihood of postoperative septic peritonitis or mortality in an additional cat in the series.

RESULTS

A total of 56 cats were included in this study; 38 cats had a DFB and 18 had an LFB. No cats developed postoperative septic peritonitis, and all cats survived. The likelihood of postoperative septic peritonitis or mortality in an additional cat was estimated to be <5.2%. Cats with an LFB were found to have a significantly higher body condition score (P = 0.047), albumin (P = 0.025), American Society of Anesthesiologists status (P = 0.027), surgery length (P <0.001) and total cost of visit (P = 0.006) when compared with cats with a DFB. Cats with LFBs were more likely to develop a surgical site infection (SSI; P = 0.007) and be administered postoperative antibiotics (P = 0.017).

CONCLUSIONS AND RELEVANCE

Cats undergoing surgery for gastrointestinal FBs had a low incidence of postoperative complications. Cats with LFBs had longer surgeries and were more likely to develop postoperative SSIs.

Outcomes and clinical features associated with surgically excised canine salivary gland carcinoma: A multi-institutional, retrospective, Veterinary Society of Surgical Oncology study

OBJECTIVE

The objective of this study was to describe the clinical features, prognostic factors, and outcomes in dogs with surgically treated salivary gland carcinoma.

STUDY DESIGN

Multi-institutional retrospective case series.

ANIMALS

Seventy-two client-owned dogs from 16 institutions with surgically excised salivary gland carcinoma.

METHODS

Medical records of dogs undergoing sialoadenectomy from January 1, 2000 to January 1, 2020 were reviewed for signalment, clinical signs, preoperative staging results, preoperative mass evaluation, complications, histopathologic diagnosis, local recurrence, metastatic disease, and survival times. Survival functions were estimated using the Kaplan-Meier estimator. Factors related to survival were individually tested using the log-rank test.

RESULTS

The overall median survival time (MST) associated with salivary carcinoma was 1886 days. Local recurrence occurred in 29/69 (42%) dogs with an overall disease-free interval (DFI) of 191 days. Metastatic disease occurred in 22/69 (31.9%) dogs, with an overall DFI of 299 days. Lymph node metastasis was present at the time of surgery in 11/38 (28.9%) dogs in which lymphadenectomy was performed at the time of surgery; these dogs had a shorter DFI at 98 days (P = .03) and MST at 248 days (P < .001).

CONCLUSION

The prognosis for dogs with salivary gland carcinoma treated surgically was more favorable than previously reported. Nodal metastasis was a negative prognostic factor for canine salivary gland carcinoma.

CLINICAL SIGNIFICANCE

Surgical intervention should be considered for dogs with salivary carcinoma.

Performing an ovariohysterectomy at the time of c-section does not pose an increase in risk of mortality, intra- or postoperative complications, or decreased mothering ability of the bitch

OBJECTIVE

Ovariohysterectomy (OVH) is frequently recommended at the time of c-section in canines, yet prior literature suggests poor mothering ability and increased morbidity to the bitch with c-section with concurrent OVH (CSOVH). The study objective was to compare maternal survival, complications, and mothering ability between bitches that underwent c-section alone (CS) or CSOVH.

ANIMALS

125 bitches.

PROCEDURES

Medical records from 2014 through 2021 were retrospectively reviewed; owners were surveyed for information up to weaning.

RESULTS

80 bitches undergoing CS and 45 bitches undergoing CSOVH were identified. There was no difference in anesthesia duration, intraoperative complications, postoperative complications, mothering ability, puppy survival to weaning, or other variables compared between groups. CSOVH bitches had longer surgery times (P = .045; 54.4 ± 20.7 min vs 46.9 ± 16.6 min) and longer time from delivery to nursing (P = .028; 75.4 ± 22.3 min vs 65.2 ± 19.5 min). Ninety (72%) owners responded to the survey. All 90 bitches survived until puppy weaning. CSOVH bitches were more frequently perceived as painful postoperatively (P = .015).

CLINICAL RELEVANCE

Performing an OVH at the time of c-section does not pose a significant increase in risk of mortality, intraoperative complications, postoperative complications, or decreased mothering ability of the bitch. The increased duration of surgery and increased time from delivery to nursing in the CSOVH group were clinically insignificant. Appropriate postoperative pain management should be emphasized post-CSOVH. Based on these results, OVH should be performed concurrently with c-section if indicated.

Safety and efficacy of intravesical instillation of resiniferatoxin in healthy cats: A preliminary study

Objectives

To evaluate the safety of intravesical application of resiniferatoxin (RTX) in healthy cats and its effects on calcitonin gene-related peptide (CGRP) and substance P (SP) produced by C-fibers.

Methods

Seven adult female cats received either 25 mL of saline (control; n = 1), or intravesical RTX at 5, 25, or 50 μg in 25 mL of saline to a final concentration of 0.2 μg/mL (318 nM), 1 μg/mL (1,591 nM), and 2 μg/mL (3,181 nM) (n = 2 per group). The treatment was instilled into the urinary bladder for 20 min. Plasma concentrations of RTX were measured at 0, 0.5, 1, and 4 h. Physical exam, complete blood count, and serum biochemical analysis were performed on day 0, 7, and 14. After 14 days, the sacral dorsal root ganglia (DRG) and the urinary bladder were harvested for histological and immunofluorescence analysis.

Results

Intravesical RTX was well tolerated and plasma concentrations were below the quantifiable limits except for one cat receiving 1 μg/mL. Mild to moderate histopathological changes, including epithelial changes, edema, and blood vessel proliferation, were observed at lower doses (0.2 and 1 μg/mL), and were more severe at the higher dose (2 μg/mL). C-fiber ablation was observed in the urinary bladder tissue at all doses, as shown by an apparent reduction of both CGRP and SP immunoreactive axons.

Conclusion

A dose of 25 μg (1 μg/mL) of RTX instilled in the urinary bladder of healthy cats appeared to decrease the density of SP and CGRP nerve axons innervating bladder and induced moderate changes in the bladder tissue.

Outcome in 38 dogs surgically treated for hepatic abscessation

OBJECTIVE

To report outcomes following surgical treatment of hepatic abscessation in dogs.

STUDY DESIGN

Retrospective.

ANIMALS

Thirty-eight dogs.

METHODS

Records from 6 institutions were evaluated for dogs undergoing surgical treatment for hepatic abscessation between 2010 and 2020. Signalment, clinical signs, medical therapy, surgical treatment, and postoperative outcome was obtained from medical records. Long-term outcome was recorded when possible. Median survival time was assessed using the Kaplan-Meier product-limit method.

RESULTS

Peritoneal effusion was documented in 32/38 dogs preoperatively, with septic peritonitis confirmed in 21/23 samples. Liver lobectomy was the most common surgery (27 dogs). A single organism was cultured in 24/35 dogs, most commonly Escherichia coli. Hepatic neoplasia was identified in 11/36 dogs. Dogs were hospitalized for a median of 5 days (range, 3-17) with complications recorded in 21 dogs (regurgitation, aspiration pneumonia, and pancreatitis most commonly). Two dogs died intraoperatively, and 6 dogs died prior to discharge. Median survival time for dogs surviving to discharge was 638 days. Of these, 19 were lost to follow up a median of 301 (range, 3-1418) days postoperatively and 11 died a median of 291 (range, 7-1292) days postoperatively. No abscess recurrence was noted.

CONCLUSION

Septic peritonitis was a common sequela to hepatic abscessation. Perioperative complications were recorded in approximately one-third of dogs. In dogs surviving the postoperative period, long-term prognosis was good.

CLINICAL SIGNIFICANCE

Dogs treated surgically for hepatic abscessation have a high risk of perioperative complications but favorable long-term prognosis and apparent low risk of recurrence.

Scar revision for incompletely or narrowly excised soft tissue sarcomas in dogs

Objective

Describe clinical features of dogs undergoing scar revision for incompletely or narrowly excised soft tissue sarcomas (STSs) in the absence of gross disease and to determine local recurrence rates following scar revision.

Animals

Thirty-three dogs with 33 scars.

Procedures

Medical records were reviewed to collect data on signalment, tumor details, pre-surgical diagnostic tests, surgical and pathologic findings for both the initial and revision surgeries, and clinical outcomes. Descriptive statistics were generated.

Results

For the initial excision, cytology was performed before surgery in 45.5% (15/33) of dogs, and information on surgical margins was rarely reported [4.0% (1/25) of circumferential and 12.0% (3/25) of deep margins]. Microscopic evidence of residual STS was identified in 18.2% of scars. Recurrence occurred in 3.0% (1/33) of dogs [median follow-up of 1127 d (1 to 3192 d)]; this dog had had no evidence of residual tumor in the scar revision pathology.

Conclusions

Despite the low identification rate of residual tumor, the local tumor recurrence rate was 3.0%, which is lower than what is historically reported for incompletely or narrowly excised STSs.

Clinical relevance

Scar revision for incompletely or narrowly excised STSs resulted in durable tumor remission in the dogs of this study. Pre-surgical diagnostic tests were not often performed in this study; these may be considered before the first excision to plan surgical margins for potentially reducing the incidence of incomplete or narrow excision. Surgical reports should include details on circumferential and deep margins to guide pathologic interpretation and future scar revision, if required.

Clinical Utility of Cytology from Preoperative Percutaneous Fine Needle Aspirates of Solitary Liver Masses in 220 Dogs: A Retrospective Study (2009-2019)

When a solitary liver mass is identified in a dog, a fine-needle aspirate (FNA) is commonly employed to attempt to obtain a diagnosis. Little information is provided in the literature evaluating the sensitivity/specificity of FNA cytology for solitary liver masses. We hypothesized that liver lesion size nor the presence of cavitation would impact the success of cytological diagnosis. Medical records were obtained for 220 client-owned dogs. Inclusion criteria included preoperative abdominal imaging, percutaneous FNA of a solitary hepatic mass with cytologic interpretation by a board-certified pathologist, and a surgical biopsy or mass excision yielding a histopathological diagnosis. Six dogs (2.7%) experienced a complication after FNA, none considered severe. The agreement rate for correct cytologic diagnosis was 22.9% (49/220). Of the neoplastic masses 18.9% (35/185) were correctly diagnosed via cytology. The overall sensitivity was 60%, and the specificity was 68.6%. Neither institution (P = 0.16), lesion size (P = 0.88), cavitation (P = 0.34), or needle gauge (P = 0.20) had an association with correct diagnosis. This study demonstrates that, although there is a low risk of complications following FNA of a hepatic mass, overall success rate for correct cytologic diagnosis based on FNA was low compared to histopathologic diagnosis.

Scar revision for incompletely or narrowly excised cutaneous mast cell tumors in dogs

Objective

Describe clinical features and outcomes of dogs undergoing scar revision for incompletely or narrowly excised cutaneous mast cell tumors without gross disease.

Animals

52 dogs undergoing 54 scar revisions.

Procedures

Retrospective record review with information collected on signalment, tumor type/location, pre-surgical diagnostics, surgical and pathologic findings for the first excision and scar revision surgeries, and follow-up. Descriptive statistics were generated.

Results

Prior to initial excision, cytology was performed on 38.9% (21/54) of tumors and the initial surgery report rarely described surgical resection margins [14.6% (7/48) of surgeries]. Residual tumor was identified pathologically in 29.6% (16/54) of scars. Local recurrence following scar revision occurred in 3.7% (2/54) of all scars [median follow-up 881.5 d (range: 0 to 3317 d)]; both scars had either complete excision of residual mast cell tumor or no evidence of mast cell tumor on scar revision and neither dog received radiation therapy.

Conclusions

Identification of residual disease was uncommon, and local recurrence was less common than previously reported for incomplete/narrow mast cell tumor excision.

Clinical relevance

Scar revision of unplanned primary excisions appears to yield a high likelihood of durable tumor remission in patients. First opinion practitioners are encouraged to avoid unplanned excisions by informing the surgical plan with cytology of the primary tumor and detailing surgical margin excision which may facilitate revision, if necessary.

Evaluation of the validity of the double two-thirds rule for diagnosing hemangiosarcoma in dogs with nontraumatic hemoperitoneum due to a ruptured splenic mass: a systematic review

OBJECTIVE

To evaluate the validity of the double two-thirds rule for a diagnosis of splenic hemangiosarcoma in dogs with nontraumatic hemoperitoneum due to a ruptured splenic mass.

SAMPLE

Systematic literature review.

PROCEDURES

3 databases (PubMed, CAB abstracts, and World of Science) were searched in November 2020. Articles were included if data on dogs with nontraumatic hemoperitoneum due to a splenic mass were included and subsequent pathologic diagnosis could be determined.

RESULTS

In total, 2,390 unique articles were identified, with 66 articles meeting the criteria for full-text review and 14 articles included for analysis. A total of 1,150 dogs were evaluated, with 73.0% (840/1,150) of dogs being diagnosed with a malignant splenic lesion and 27.0% (310/1,150) being diagnosed with a benign splenic lesion. Of the malignancies, 87.3% (733/840) were hemangiosarcoma. Levels of evidence were low, and bias was high as most included studies were retrospective case series.

CLINICAL RELEVANCE

The double two-thirds rule should be refined when evaluating dogs with nontraumatic hemoperitoneum from a ruptured splenic mass, with more dogs being diagnosed with a malignancy and hemangiosarcoma specifically than the double two-thirds rule indicates. These findings may be useful in an emergency setting to guide owners on potential diagnoses for dogs with nontraumatic hemoperitoneum due to a ruptured splenic mass. However, there remains a portion of these dogs with benign conditions and nonhemangiosarcoma malignancies that may have a good long-term prognosis compared to dogs with hemangiosarcoma. Studies with higher levels of evidence, lower risks of bias, and large case numbers are needed in the literature.

Risk factors for neonatal mortality prior to hospital discharge in brachycephalic and nonbrachycephalic dogs undergoing cesarean section

OBJECTIVES

To compare neonatal survival to discharge rates between brachycephalic and nonbrachycephalic dogs undergoing cesarean section (c-section) and identify risk factors for neonatal mortality.

STUDY DESIGN

Retrospective study.

ANIMALS OR SAMPLE POPULATION

A total of 480 puppies from 90 bitches undergoing 106 c-sections.

METHODS

Medical records of c-sections performed between January 2012 and September 2021 were reviewed. Data collected included brachycephalic versus nonbrachycephalic breed, elective versus emergency c-section, litter size (c-section and total [including those born prior to and via c-section]), and neonatal survival to discharge. A generalized linear mixed model (univariable and multivariable) was performed to evaluate variables versus neonatal survival.

RESULTS

Overall neonatal survival to discharge was 93.1% (447/480); survival was similar between brachycephalic and nonbrachycephalic breeds (p = .221, 202/213 [94.8%] brachycephalic survival, 245/267 [91.8%] nonbrachycephalic survival). Puppies delivered via elective c-section were more likely to survive compared to emergency c-section (p < .001, 238/240 [99.2%] elective survival, 209/240 [87.1%] emergency survival). Puppies delivered in larger c-section litters were more likely to survive (p < .004) compared to smaller litters. Total litter size had no effect on survival.

CONCLUSION

Brachycephalism had no effect on neonatal survival. Puppies delivered via elective c-section were more likely to survive compared to puppies delivered via emergency c-section.

CLINICAL SIGNIFICANCE

Outcomes following c-section are similar between brachycephalic and nonbrachycephalic breeds. While it is preferable to encourage selective breeding for bitches that are able to whelp naturally, elective c-section should be considered in bitches at high risk for dystocia to maximize neonatal survival.

Clinical presentation and outcome in cats with aural squamous cell carcinoma: a review of 25 cases (2010-2021)

CASE SERIES SUMMARY

Ear canal neoplasia is uncommon in cats. Ceruminous gland adenocarcinoma is the most frequently reported malignant neoplasm of the feline ear canal, and squamous cell carcinoma (SCC) is the most common malignant neoplasm diagnosed in the feline middle ear. However, limited information exists on the outcome of cats diagnosed with SCC of the ear canal, middle or inner ear. Therefore, the objective of this study was to describe the outcome of cats diagnosed with SCC affecting these locations. Medical records were reviewed at multiple institutions to identify cats with a definitive diagnosis of SCC. Twenty-five cats were identified. Eleven cats were treated with surgery, eight with medical management, two with coarse fractionated radiation therapy, two with a combination of coarse fractionated radiation therapy and chemotherapy, one with a combination of surgery and coarse fractionated radiation therapy, one cat with systemic chemotherapy and one cat received no treatment following diagnosis. The median survival time of cats treated with surgery was 168 days vs 85 days (P = 0.28) for those treated palliatively with either medical management, radiation therapy, chemotherapy, or a combination of radiation therapy and chemotherapy.

RELEVANCE AND NOVEL INFORMATION

This case series documented that SCC of the ear canal, middle and/or internal ear is a locally aggressive tumor that carries an overall poor prognosis. The median survival time for cats treated with surgery was longer than that with any other modality, but this difference was not statistically significant.

Surgical treatment of deep neck infections in 19 dogs

OBJECTIVE

Describe clinical features, treatment, and outcomes in dogs with deep neck infections.

ANIMALS

19 dogs undergoing surgical treatment of deep neck infections from January 1, 2015, through December 31, 2020.

PROCEDURES

Retrospective record review was conducted, with data collected including clinical signs; neutrophil-to-lymphocyte ratio (NLR); diagnostic imaging, surgical, and histopathologic findings; and follow-up. Spearman correlation and Wilcoxon rank sum were used to compare variables to NLR.

RESULTS

All dogs had cervical swelling, and 9 were febrile. On CT, a distinct mass or abscess (7/13) or abscessed lymph node (4/13) was common, with contrast enhancement (10/13), fluid tracking (8/13), and displacement of the trachea, pharynx, or larynx (6/13) also frequently seen. Foreign material was suspected on CT for 4 dogs and was identified at surgery or histopathology for 4 dogs, only 1 of which was suspected on CT. Histopathology most commonly revealed pyogranulomatous inflammation (14/15). Increasing NLR was moderately correlated to a decreased duration of clinical signs before presentation (ρ = –0.548; P = .035) and an increased length of hospitalization (ρ = 0.645; P = .009). Bacterial culture was submitted for all dogs, and polymicrobial infections were common (8/19). Broad-spectrum empirical antimicrobials were commonly prescribed. Change in antimicrobial treatment based on culture was uncommon (3/19). All dogs survived to hospital discharge; 18 dogs with long-term follow-up had complete resolution of clinical signs.

CLINICAL RELEVANCE

CT was useful to plan for surgery, and surgical treatment resulted in resolution of clinical signs in all dogs with long-term follow-up available. Empirical antimicrobial treatment, such as amoxicillin–clavulanic acid or ampicillin-sulbactam, should be considered.

Perioperative characteristics, histologic diagnosis, complications, and outcomes of dogs undergoing percutaneous drainage, sclerotherapy or surgical management of intrarenal cystic lesions: 18 dogs (2004-2021)

BACKGROUND

Canine intrarenal cystic lesions (ICLs) are infrequently reported in the veterinary literature. Several treatment options have been described including cyst fenestration (partial nephrectomy/deroofing) +/- omentalization, sclerotherapy using alcohol as a sclerosing agent, percutaneous cyst drainage (PCD), and ureteronephrectomy. Information regarding presenting clinical signs, physical examination findings, histologic diagnosis and outcomes of dogs with ICLs treated by different methods is limited. Medical records of 11 institutions were retrospectively reviewed to identify dogs that underwent PCD, sclerotherapy, surgical deroofing +/- omentalization, or ureteronephrectomy for management of ICLs from 2004 to 2021. Six weeks postoperative/post-procedural follow-up was required. Cases suspected to represent malignancy on preoperative imaging were excluded. The study objective was to provide information regarding perioperative characteristics, complications, and outcomes of dogs undergoing treatment of ICLs.

RESULTS

Eighteen dogs were included, with 24 ICLs treated. Ten had bilateral. There were 15 males and 3 females, with crossbreeds predominating. PCD, sclerotherapy, deroofing and ureteronephrectomy were performed in 5 (5 ICLs treated), 7 (11 ICLs), 6 (6), and 7 (7) dogs, respectively, with 5 dogs undergoing > 1 treatment. Seven dogs experienced 8 complications, with requirement for additional intervention commonest. PCD, sclerotherapy and deroofing resulted in ICL resolution in 0/5, 3/11 and 3/6 treated ICLs, respectively. Histopathology identified renal cysts (RCs) in 7/13 dogs with histopathology available and neoplasia in 6/13 (4 malignant, 2 benign). Of 5 dogs diagnosed histopathologically with neoplasia, cytology of cystic fluid failed to identify neoplastic cells. Among 7 dogs with histologically confirmed RCs, 4 had concurrent ICLs in ipsilateral/contralateral kidney, compared with 2/6 dogs with histologically confirmed neoplasia.

CONCLUSIONS

Benign and neoplastic ICLs were approximately equally common and cystic fluid cytology failed to differentiate the 2. Among renal-sparing treatments, deroofing most commonly resulted in ICL resolution. Presence of concurrent ICLs in ipsilateral/contralateral kidney does not appear reliable in differentiating benign from malignant ICLs.

Surgical ligation of patent ductus arteriosus in dogs: Incidence and risk factors for rupture

OBJECTIVE

To determine the rates of rupture and mortality associated with surgical ligation of patent ductus arteriosus (PDA) in dogs and to identify risk factors for rupture.

STUDY DESIGN

Retrospective cohort.

ANIMALS

Two-hundred and eighty-five dogs with PDA undergoing surgical ligation.

METHODS

Information regarding signalment, weight, surgical findings, complications, presence of residual flow, and survival was recorded. Age, weight, and presence of residual flow were compared between cases with and without rupture.

RESULTS

The initial surgical approach was extrapericardial (144), intrapericardial (46), not reported (94), or Jackson-Henderson (1). Rupture of the PDA occurred in 7.0% of dogs (20/285, 13 extrapericardial, 3 intrapericardial, 4 not reported). No difference in age or weight was found between dogs with and without rupture. Overall mortality was 0.4% (1/285). Additional major complications occurred in 1.4% of dogs, all in the nonrupture group. The overall rate of residual flow after ligation was 9.4%. Dogs with rupture were more likely to have residual flow than those without rupture (P = .012). If ligation was performed after rupture (rather than hemostasis only), no difference in residual flow rates (P = .398) was noted between dogs with rupture and those without.

CONCLUSION

The rate of rupture with surgical ligation of PDAs was low. No specific risk factors for rupture were identified.

CLINICAL SIGNIFICANCE

Successful treatment of PDA rupture is possible, evidenced by the low mortality rate in this population of dogs. Ligation of the PDA after rupture, either in the concurrent or a subsequent procedure, reduces the odds of residual flow.

MicroRNAs are differentially expressed in the serum and renal tissues of cats with experimentally induced chronic kidney disease: a preliminary study

OBJECTIVE

To identify differentially expressed microRNA in the serum and renal tissues of cats with experimentally induced chronic kidney disease (CKD).

SAMPLE

Banked renal tissues and serum from 4 cats.

PROCEDURES

Cats previously underwent 90-minute unilateral ischemia with delayed contralateral nephrectomy 3 months after ischemia. Tissues were collected from the contralateral kidney at the time of nephrectomy and from the ischemic kidney 6 months after nephrectomy (study end). Serum was collected prior to ischemia (baseline serum) and at study end (end point serum). Total RNA was isolated from tissues and serum, and microRNA sequencing was performed with differential expression analysis between the contralateral and ischemic kidney and baseline and end point serum.

RESULTS

20 microRNAs were differentially expressed between ischemic and contralateral kidneys, and 52 microRNAs were differentially expressed between end point and baseline serum. Five microRNAs were mutually differentially expressed between ischemic and contralateral kidneys and baseline and end point serum, with 4 (mir-21, mir-146, mir-199, and mir-235) having increased expression in both the ischemic kidney and end point serum and 1 (mir-382) having increased expression in the ischemic kidney and decreased expression in end point serum. Predicted target search for these microRNA revealed multiple genes previously shown to be involved in the pathogenesis of feline CKD, including hypoxia-inducible factor-1α, transforming growth factor-β, hepatocyte growth factor, fibronectin, and vascular endothelial growth factor A.

CLINICAL RELEVANCE

MicroRNAs were differentially expressed after CKD induction in this preliminary study. Regulation of renal fibrosis in feline CKD may occur through microRNA regulation of mRNAs of pro- and anti-fibrotic genes.

Dogs ≥ five years of age at the time of congenital extrahepatic portosystemic shunt diagnosis have better long-term outcomes with surgical attenuation than with medical management alone

OBJECTIVE

To determine the outcome in dogs diagnosed with congenital extrahepatic portosystemic shunts (EHPSS) at ≥ 5 years of age treated with medical management only (M) or with surgical attenuation (S). The hypothesis was that dogs undergoing surgical attenuation would have a longer survival time than dogs undergoing medical management only.

ANIMALS

351 dogs definitively diagnosed with EHPSS at ≥ 5 years of age.

PROCEDURES

Medical records from 2009 to 2019 at 16 veterinary teaching hospitals were evaluated. Data collected included signalment, clinical signs at diagnosis, clinicopathologic data, surgical and medical treatments, shunt morphology, clinical signs and medical treatments at 6 to 12 months after diagnosis, and survival time.

RESULTS

351 dogs (M, 119 [33.9%]; S, 232 [66.1%]) were included in the study. Survival time was longer with surgery than medical management (hazard ratio, 4.2; M, 3.4 years; S, 10.9 years). Continued clinical signs at 6 to 12 months after diagnosis were more common with medical management (M, 40% [33/88]; S, 14% [21/155]). Continued medical treatments at 6 to 12 months after diagnosis were more common in the medical management group (M, 78% [69/88]; S, 34% [53/155]). Perioperative mortality rate was 7.3%.

CLINICAL RELEVANCE

Dogs diagnosed at ≥ 5 years of age with EHPSS have significantly better survival times and fewer clinical signs with surgical attenuation, compared with medical management. Older dogs have similar surgical mortality rates to dogs of all ages after surgical EHPSS attenuation.

Short- and long-term survival after adrenalectomy in 53 dogs with pheochromocytomas with or without alpha-blocker therapy

OBJECTIVE

To report data related to the short- and long-term survival of dogs undergoing adrenalectomy for pheochromocytoma, and to determine the influence of preoperative alpha-blocker therapy.

STUDY DESIGN

Retrospective.

ANIMALS

Fifty-three dogs.

METHODS

Medical records were reviewed for dogs diagnosed with pheochromocytoma and treated with adrenalectomy between 2010 and 2020. Preoperative management, imaging studies, intraoperative cardiovascular instability, complications, and procedural information were recorded. When applicable, duration of survival and cause of death, time to recurrence or metastasis, and postoperative complications were recorded.

RESULTS

During anesthesia, a hypertensive episode was documented in 46/53 dogs and arrhythmias were recorded in 16/53 dogs. Of these, 37/46 hypertensive dogs and 11/16 dogs with arrhythmias were treated with an alpha-blocker before surgery. Intraoperative systolic blood pressures reached higher levels by a magnitude of nearly 20% in dogs that were treated preoperatively with an alpha-blocker (P = .01). All dogs survived surgery and 44 survived to discharge. Follow up ranged from 6 to 1653 days (median 450 days). Median survival time for dogs discharged from the hospital was 1169 days (3.2 years). Recurrence and metastasis were suspected in 3 and 8 dogs, respectively.

CONCLUSION

Most dogs survived the immediate postoperative period and achieved long-term survival with a low reported incidence of tumor recurrence or metastasis. Preoperative alpha-blocker therapy was not associated with increased survival.

CLINICAL SIGNIFICANCE

The favorable outcomes reported in this study should be taken into consideration when discussing treatment options for dogs with pheochromocytomas. This study provides no evidence to support preoperative alpha-blocker therapy.

Incidence of and risk factors for surgical site infection following canine limb amputation

OBJECTIVE

To determine the incidence of and risk factors for surgical site infection (SSI) following canine thoracic and pelvic limb amputations.

STUDY DESIGN

Retrospective, multicenter study.

ANIMALS

Dogs (n = 248).

METHODS

Medical records were reviewed for preoperative, intraoperative, and postoperative variables including indication for amputation, amputation type, method of muscle transection, duration of surgery and anesthesia, and wound classification. Follow up was ≥30 days or until SSI development. Logistic regression and Fisher's exact tests were used to compare SSI incidence to variables of interest.

RESULTS

The incidence of SSI was 12.5% for all procedures and 10.9% for clean procedures. Factors increasing odds of SSI were muscle transection with a bipolar vessel sealing device (P = .023 for all procedures, P = .025 for clean procedures), procedure classified as other than clean (P = .003), and indication for amputation of bacterial infection (P = .041) or traumatic injury (P = .003) compared to neoplasia.

CONCLUSION

Use of bipolar vessel sealing devices for muscle transection increased the odds of developing an SSI whereas use of electrosurgery and/or sharp transection did not. Dogs with surgical sites that were other than clean, or with bacterial infection and/or traumatic injury were also at increased odds of SSI.

CLINICAL SIGNIFICANCE

Use of electrosurgery or sharp transection for muscle transection should be considered rather than use of bipolar vessel sealing devices to decrease odds of SSI in dogs undergoing limb amputation. Further studies across a variety of procedures are needed to validate these findings given the increasing popularity of these devices in veterinary medicine.

Jejunal strangulation and incarceration associated with bilateral perineal hernias in a neutered male dog

CASE DESCRIPTION

An 8-year-old 6.8-kg neutered male Dachshund was presented for evaluation of vomiting, diarrhea, anorexia, and swelling over the right perineal region. The dog had a history of a bilateral perineal herniorrhaphy and castration 14 months prior to presentation.

CLINICAL FINDINGS

Bilateral perineal hernias were confirmed by digital rectal examination. Abdominal ultrasonography confirmed the presence of intestine within the right hernia. Three days after admission to the hospital, the region of the right perineal hernia became painful, erythematous, and edematous. Computed tomography revealed jejunal incarceration within the right hernia with dilation of 1 jejunal segment that indicated intestinal obstruction.

TREATMENT AND OUTCOME

Abdominal exploratory surgery was performed, during which irreducible small intestinal incarceration was confirmed. Intra-abdominal jejunal resection and anastomosis was performed, and an approximately 13-cm-long section of the jejunum was resected. Bilateral perineal herniorrhaphies with internal obturator and superficial gluteal muscle transposition were performed. Six months after surgery, digital rectal examination of the dog revealed that the repair was intact. The dog had no perineal hernia-related clinical signs at the time of the recheck examination.

CLINICAL RELEVANCE

For the dog of the present report, surgical management of small intestinal strangulation associated with a perineal hernia was successful. Although a portion of the small intestines can frequently be found within perineal hernias in dogs, perineal hernia-related small intestinal strangulation has not been previously described, to the authors' knowledge. Veterinarians and clients should be aware of this potential complication secondary to perineal hernia and be prepared to perform an abdominal surgical procedure to address small intestinal incarceration in affected dogs.

Dogs undergoing surgical excision of mast cell tumors are not at increased risk of incisional complications

OBJECTIVE

To retrospectively compare the incidence of incisional complications in dogs undergoing surgery for mast cell tumors (MCTs) and soft tissue sarcomas (STSs).

ANIMALS

218 dogs.

PROCEDURES

Dogs that underwent excision of ≥ 1 MCT, STS, or both from January 2014 to July 2019 and had ≥ 30 days postoperative follow-up were included. Signalment; anesthesia and surgery time; administration of propofol; tumor type, grade, location, and size; intended surgical margins; histologic margins; perioperative radiation, chemotherapy, and corticosteroid and antihistamine (MCT group) treatments; and incisional complications (classified as major or minor) were recorded. Follow-up information was obtained from owners or primary care veterinarians, if needed. Incidence and severity of incisional complications were compared between the MCT and STS groups. Potential risk factors were assessed for associations with incisional complications by simple and multiple logistic regression analysis.

RESULTS

The 218 dogs underwent surgery for 293 tumors (209 MCTs and 84 STSs). Complication rates did not differ between MCT (28/209 [13%]) and STS (12/84 [14%]) groups. For the MCT group, incomplete margins (vs complete or narrow), increasing Patnaik tumor grade, and postoperative chemotherapy (yes vs no) were associated with increased odds of incisional complications on simple regression. On multiple logistic regression, postoperative chemotherapy was associated with increased odds of incisional complications for the MCT group and both groups combined.

CONCLUSIONS AND CLINICAL RELEVANCE

On the basis of the results, we suggest that chemotherapy be used with caution ≤ 30 days after surgery for dogs with MCTs. Corticosteroid administration was not associated with incisional complications for the MCT group in this study.

Anatomic characterization of the location of the esophageal ostium relative to the rima glottidis on CT in adult Labrador Retrievers

OBJECTIVE

To characterize the anatomic location of the esophageal ostium relative to the rima glottidis in adult Labrador Retrievers with the use of CT.

ANIMALS

98 CT scans of 75 adult Labrador Retrievers.

PROCEDURES

A search of the medical records database identified records of Labrador Retrievers that underwent CT of the head and neck between January 1, 2015, and December 31, 2018. Evaluators, blinded to each other's results, reviewed CT images and measured esophageal area at the level of the rima glottidis. For each dog, the left esophageal percentage (LEP) was calculated as the esophageal area left of the rima glottidis midline divided by the overall esophageal area at that level. Variables (age, sex, patient position, intubation status, and maxillary support during CT) were evaluated for association with LEP. The CT images of dogs that had multiple scans were assessed for within-patient variance.

RESULTS

Mean LEP was 56.2 ± 18.1% for all dogs. Only right lateral recumbency was significantly associated with LEP, with a lower LEP for dogs positioned in right lateral recumbency (42.4 ± 12.7%), compared with left lateral (63.0 ± 7.4%) or sternal (57.3 ± 18.8%) recumbency. No association was detected between LEP and other variables assessed. Eleven dogs had multiple CT scans; within-patient variance for LEP was ± 26.6%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that, although most dogs had an LEP > 50%, the esophageal ostium was fairly centrally located in most dogs and may be more mobile than previously thought. Additional research is warranted to assess this mobility and whether the esophageal ostium location, relative to the larynx, affects the incidence of aspiration pneumonia in dogs undergoing surgical treatment for geriatric-onset laryngeal paralysis and polyneuropathy.

Evaluation of outcomes following subtotal colectomy for the treatment of idiopathic megacolon in cats

OBJECTIVE

To evaluate outcomes in cats undergoing subtotal colectomy for the treatment of idiopathic megacolon and to determine whether removal versus nonremoval of the ileocecocolic junction (ICJ) was associated with differences in outcome.

ANIMALS

166 client-owned cats.

PROCEDURES

For this retrospective cohort study, medical records databases of 18 participating veterinary hospitals were searched to identify records of cats with idiopathic megacolon treated by subtotal colectomy from January 2000 to December 2018. Data collection included perioperative and surgical variables, complications, outcome, and owner perception of the procedure. Data were analyzed for associations with outcomes of interest, and Kaplan-Meier survival time analysis was performed.

RESULTS

Major perioperative complications occurred in 9.9% (15/151) of cats, and 14% (12/87) of cats died as a direct result of treatment or complications of megacolon. The median survival time was not reached. Cats with (vs without) a body condition score < 4/9 (hazard ratio [HR], 5.97), preexisting heart disease (HR, 3.21), major perioperative complications (HR, 27.8), or long-term postoperative liquid feces (HR, 10.4) had greater hazard of shorter survival time. Constipation recurrence occurred in 32% (24/74) of cats at a median time of 344 days and was not associated with retention versus removal of the ICJ; however, ICJ removal was associated with long-term liquid feces (OR, 3.45), and a fair or poor outcome on owner assessment (OR, 3.6).

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that subtotal colectomy was associated with long survival times and a high rate of owner satisfaction. Removal of the ICJ was associated with less favorable outcomes in cats of the present study.

A Simulated Tumor for Teaching Principles of Surgical Oncology for Biopsy and Excision of Skin and Subcutaneous Masses to Veterinary Students

Tumors of the skin and subcutaneous tissues are commonly encountered in primary care practice. The most common of these tumors are mast cell tumors and soft tissue sarcomas, for which the primary treatment is most often surgical excision. Understanding surgical margins, particularly the deep fascial plane, can be difficult for veterinary students. Current techniques to teach these concepts typically rely on cadaver-based laboratories, which require simulated tumors to improve the realism of the laboratory. Tumors can be difficult to replicate in cadaver laboratories; thus a new technique for a simulated tumor was developed. A gelatin-based simulated tumor was injected into the subcutaneous space in two different sites in canine cadavers. Students then practiced incisional biopsy and wide excision of a subcutaneous mass. Students were able to appropriately perform both techniques using the simulated tumors. When the deep margin was not clean on the wide excision, students were able to understand the error by identifying the simulated tumor, reinforcing the concept of obtaining an appropriate deep fascial plane. In summary, this gelatin-based simulated tumor technique was cost-effective, easy to perform, and effective for the teaching laboratory.

Influence of doxapram and intermittent 10% carbon dioxide inspiration on cardiovascular and laryngeal functions in anesthetized dogs

OBJECTIVE

To compare the effects of two doses of doxapram intravenous injection and carbon dioxide inhalation on the cardiovascular and laryngeal functions of anesthetized hounds.

STUDY DESIGN

Experimental study.

ANIMALS

Six healthy adult dogs.

METHODS

In a Latin-square design, the mean arterial blood pressure (MABP) and heart rate (HR) were recorded continuously. The inspiratory normalized glottic gap areas (iNGGA) were measured before and after each stimulation with 0.55 mg/kg of doxapram (L-DOX), 2.2 mg/kg of doxapram (H-DOX), or 90 s of inhalation of 10% carbon dioxide in oxygen (I-CO₂ ). The stimulations were tested in duplicate or triplicate. Video clips of the laryngeal movement were scored by board-certified surgeons masked to the treatment.

RESULTS

The MABP increased with L-DOX and H-DOX up to 81% (both p < .001 compared to I-CO₂ ), and persisted during the other stimulations (both p < .001). An intermittent tachycardic effect of up to 79% increase in HR was observed with doxapram. The HR following H-DOX was higher than L-DOX and I-CO₂ (both p < .016). Neither hypertension nor tachycardia was observed with I-CO₂ . The iNGGA increased with all treatments (p < .001). The iNGGA was greater with H-DOX than L-DOX and I-CO₂ (both p < .007). All treatments received higher scores (all p < .001) with acceptable inter- and intra-observers Krippendorff's alphas.

CONCLUSION

All treatments were effective respiratory stimulants in anesthetized dogs; however, doxapram caused hypertension and tachycardia.

CLINICAL SIGNIFICANCE

Carbon dioxide inhalation might improve arytenoid motion without cardiovascular effects in dogs during clinical airway examinations.

Identification of serum microRNAs with differential expression between dogs with splenic masses and healthy dogs with histologically normal spleens

OBJECTIVE

To identify differential microRNA (miRNA) expression in dogs with splenic hemangiosarcoma, splenic hematoma, and histologically normal spleens.

ANIMALS

Dogs with splenic hemangiosarcoma (n = 10), splenic hematoma (n = 5), and histologically normal spleens (n = 5).

PROCEDURES

Splenic tissue and serum samples were collected from dogs with splenic masses (ie, hemangiosarcoma or hematoma samples) and healthy control dogs (ie, control samples), and total RNA was extracted. Reverse transcription quantitative real-time PCR was performed with 28 miRNAs associated with hemangiosarcoma, angiosarcoma, or associated genes. Differential expression analysis was performed.

RESULTS

Control tissue and serum samples had similar miRNA expression patterns, and hemangiosarcoma tissue and serum samples did not. Hemangiosarcoma serum samples had higher expression than hemangiosarcoma tissue for 13 miRNAs and lower expression for 1 miRNA. Control tissue and hemangiosarcoma tissue had varying expressions for 12 miRNAs, with 10 more highly expressed in control samples and 2 more highly expressed in hemangiosarcoma samples. Five miRNAs (miR-214-3p, miR-452, miR-494-3p, miR-497-5p, miR-543) had significantly different expression in serum between dogs with splenic masses (ie, hemangiosarcoma or hematoma) and serum of dogs with histologically normal spleens, with higher expression in the serum of dogs with splenic masses for all 5 miRNAs.

CONCLUSIONS AND CLINICAL RELEVANCE

5 circulating miRNAs were identified that distinguished dogs with splenic hemangiosarcoma or hematoma from those with histologically normal spleens. These 5 miRNAs had higher expression in dogs with splenic masses, indicating upregulation of these circulating miRNAs occurs in these splenic disease states. These miRNAs may be useful as a noninvasive screening tool that uses serum to identify dogs with splenic masses.

Analysis of risk factors associated with complications following mandibulectomy and maxillectomy in dogs

OBJECTIVE

To provide information about complication rates and the risk factors for complications with mandibulectomy and maxillectomy procedures in dogs.

ANIMALS

459 client-owned dogs that underwent a mandibulectomy or maxillectomy between January 1, 2007, and January 1, 2018.

PROCEDURES

Inclusion criteria included a complete medical record that contained an anesthesia record, surgical report, available histopathology results, and results of CBC and serum biochemical analysis before surgery. A minimum follow-up of 90 days after surgery was required.

RESULTS

271 complications occurred in 171 of 459 (37.3%) dogs. Eighteen complications were not given a severity description. Of the remaining 253 complications, most were considered minor (157/253 [62.1%]). Multivariable logistic regression analysis revealed that only increased surgical time had a significant (OR, 1.36; 95% CI, 1.12 to 1.54) association with the occurrence of ≥ 1 complication. For each additional hour of surgery, the odds of complications increased by 36%. Preoperative radiation therapy or chemotherapy increased the odds of incisional dehiscence or oral fistula formation (OR, 3.0; 95% CI, 1.3 to 7.2). Additionally, undergoing maxillectomy, compared with mandibulectomy, increased the odds of incisional dehiscence or oral fistula formation (OR, 1.8; 95% CI, 1.1 to 3.1). Two hundred forty-four of 271 (90.0%) complications occurred in the perioperative period (0 to 3 months after surgery).

CONCLUSIONS AND CLINICAL RELEVANCE

Compared with mandibulectomy, performing maxillectomy increased the risk for incisional dehiscence or oral fistula formation. Mandibulectomy and maxillectomy had a moderate risk for a complication.

Evaluation of short-term risk factors associated with dehiscence and death following full-thickness incisions of the large intestine in cats: 84 cases (1993-2015)

OBJECTIVE

To evaluate short-term risk factors associated with dehiscence and death in cats undergoing full-thickness large intestinal incisions.

ANIMALS

84 client-owned cats that had undergone full-thickness large intestinal incisions and for which information regarding outcome through postoperative day 7 was available.

PROCEDURES

Medical records from 4 veterinary teaching hospitals were reviewed. For cats that met the inclusion criteria, signalment, history, laboratory test results, surgical and medical procedures, perioperative complications, and outcome were analyzed. A Fisher exact or Wilcoxon rank sum test was used to identify individual variables associated with dehiscence of intestinal incisions or patient nonsurvival to hospital discharge or both.

RESULTS

84 cats met the inclusion criteria. The overall dehiscence and survival to hospital discharge rates were 8.3% (7/84 cats) and 94% (79/84 cats), respectively. Factors associated with dehiscence and nonsurvival to hospital discharge included presence of band neutrophils, performance of partial colectomy with colonic resection and anastomosis, administration of blood products, postoperative cardiopulmonary arrest, and incisional inflammation or infection. Factors associated with nonsurvival to hospital discharge only included low serum globulin concentration, repair of colonic trauma or dehiscence, and postoperative colonic dehiscence. Factors associated with dehiscence only included hypoalbuminemia, renal dysfunction, administration of blood products or > 2 classes of antimicrobials, and intra-abdominal fecal contamination.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that intestinal dehiscence and mortality rates associated with large intestinal incisions in cats may be higher than previously proposed, although the risk of either outcome was still low. Factors suggestive of systemic illness were associated with colonic dehiscence or death, and focused prospective studies of risk factors are warranted.

Evaluation of concurrent perineal hernia in adult male dogs presenting with nontraumatic, acquired inguinal hernias

A possible association between the development of nontraumatic, acquired inguinal hernias (NAIH) and perineal hernias (PH) has been postulated in adult dogs. The objective of this study was to evaluate the frequency of concurrent diagnosis of PH in dogs presented with NAIH and determine potential risk factors for concurrent PH and NAIH. Medical records of adult male dogs presented for NAIH to 4 hospitals between 2007 and 2017 were retrospectively reviewed. Twenty-one dogs with NAIH were included, 8 of which had concurrent PH. There were no significant differences between dogs with and without PH; however, among dogs with both conditions, intact dogs (8.1 ± 1.4 years) were younger than neutered dogs (11.7 ± 1.0 years; P = 0.007). Thirty-eight percent of male dogs presenting for NAIH had concurrent PH, indicating that these conditions commonly occur together. Dogs presenting for NAIH should be carefully evaluated for concurrent PH before surgical intervention.

Effect of contrast agent viscosity and massage on success of computed tomography lymphangiography with aqueous contrast for sentinel lymph node identification in healthy dogs

Sentinel lymph node (SLN) evaluation is important for accurate cancer staging. Computed tomography (CT) lymphangiography with aqueous contrast is a feasible technique for SLN identification in dogs. Although most studies report success rates around 90%, success rates as low as 60% have been reported. One reason for low success rates may be the difference in viscosity of the various agents used in comparison to normal lymph viscosity. The objective of this study was to evaluate contrast agents of differing viscosities for use in CT lymphangiography for SLN identification and to determine the influence of massage on contrast flow rates. The hypothesis was that lower viscosity agents would have a higher success rate and faster time to identification of the SLN than higher viscosity agents and that massage would increase contrast flow rates. Dogs were anaesthetised and CT lymphangiography was performed with four contrast agents of differing viscosities in a randomized crossover design. Injections were made on the dorsal pes bilaterally on two study days and the popliteal lymph nodes were evaluated for contrast uptake. There was no significant difference in success of SLN identification or time to SLN identification among the four agents. Massage of the injection site increased rate of contrast flow through the lymphatics. No specific recommendation for one contrast agent over another can be made with these results. Massage is recommended to improve lymphatic flow when performing CT lymphangiography with aqueous contrast in dogs.

Management of a urethral tear with porcine small intestinal submucosa-augmented urethroplasty and balloon dilation for subsequent urethral stricture in a cat

CASE DESCRIPTION

As a result of vehicular trauma, a 3-year-old neutered male domestic shorthair cat sustained luxation of the sacrocaudal joint and a urethral tear.

CLINICAL FINDINGS

Retrograde contrast urethrocystography revealed a urethral tear at the level of the ischiatic tuberosity. Conservative treatment for 7 days with a urethral catheter was unsuccessful.

TREATMENT AND OUTCOME

An approach for a perineal urethrostomy was performed and revealed a large urethral tear (4 mm in length in a craniocaudal orientation and encompassing approx 50% of the urethral circumference) proximal to the bulbourethral glands. Urethroplasty was performed with a graft of a rectangular section of single-layer porcine small intestinal submucosa. Perineal urethrostomy was then completed routinely, and a urethral catheter was left in place for 5 days. Two days after removal of the urethral catheter, stranguria was noted. Retrograde contrast urethrocystography revealed a urethral stricture. Balloon dilation of the urethral stricture was performed, and the cat's stranguria improved. Ten weeks following balloon dilation, the cat developed hematuria, and a urinary tract infection and urethral stricture were diagnosed. Balloon dilation was repeated with instillation of triamcinolone solution at the stricture site. Eighteen months later (approx 21 months after the initial surgery), the cat was urinating normally.

CLINICAL RELEVANCE

The outcome for the cat of this report indicated that porcine small intestinal submucosa may be used to successfully augment urethroplasty for treatment of traumatic urethral tears in cats. Urethral balloon dilation with triamcinolone instillation may be used to treat postoperative urethral strictures.

Exploring the predictive value of lesion topology on motor function outcomes in a porcine ischemic stroke model

Harnessing the maximum diagnostic potential of magnetic resonance imaging (MRI) by including stroke lesion location in relation to specific structures that are associated with particular functions will likely increase the potential to predict functional deficit type, severity, and recovery in stroke patients. This exploratory study aims to identify key structures lesioned by a middle cerebral artery occlusion (MCAO) that impact stroke recovery and to strengthen the predictive capacity of neuroimaging techniques that characterize stroke outcomes in a translational porcine model. Clinically relevant MRI measures showed significant lesion volumes, midline shifts, and decreased white matter integrity post-MCAO. Using a pig brain atlas, damaged brain structures included the insular cortex, somatosensory cortices, temporal gyri, claustrum, and visual cortices, among others. MCAO resulted in severely impaired spatiotemporal gait parameters, decreased voluntary movement in open field testing, and higher modified Rankin Scale scores at acute timepoints. Pearson correlation analyses at acute timepoints between standard MRI metrics (e.g., lesion volume) and functional outcomes displayed moderate R values to functional gait outcomes. Moreover, Pearson correlation analyses showed higher R values between functional gait deficits and increased lesioning of structures associated with motor function, such as the putamen, globus pallidus, and primary somatosensory cortex. This correlation analysis approach helped identify neuroanatomical structures predictive of stroke outcomes and may lead to the translation of this topological analysis approach from preclinical stroke assessment to a clinical biomarker.

Semi-Automated Cell and Tissue Analyses Reveal Regionally Specific Morphological Alterations of Immune and Neural Cells in a Porcine Middle Cerebral Artery Occlusion Model of Stroke

Histopathological analysis of cellular changes in the stroked brain provides critical information pertaining to inflammation, cell death, glial scarring, and other dynamic injury and recovery responses. However, commonly used manual approaches are hindered by limitations in speed, accuracy, bias, and the breadth of morphological information that can be obtained. Here, a semi-automated high-content imaging (HCI) and CellProfiler histological analysis method was developed and used in a Yucatan miniature pig permanent middle cerebral artery occlusion (pMCAO) model of ischemic stroke to overcome these limitations. Evaluation of 19 morphological parameters in IBA1⁺ microglia/macrophages, GFAP⁺ astrocytes, NeuN⁺ neuronal, FactorVIII⁺ vascular endothelial, and DCX⁺ neuroblast cell areas was conducted on porcine brain tissue 4 weeks post pMCAO. Out of 19 morphological parameters assessed in the stroke perilesional and ipsilateral hemisphere regions (38 parameters), a significant change in 3838 measured IBA1⁺ parameters, 3438 GFAP⁺ parameters, 3238 NeuN⁺ parameters, 3138 FactorVIII⁺ parameters, and 2838 DCX⁺ parameters were observed in stroked vs. non-stroked animals. Principal component analysis (PCA) and correlation analyses demonstrated that stroke-induced significant and predictable morphological changes that demonstrated strong relationships between IBA1⁺, GFAP⁺, and NeuN⁺ areas. Ultimately, this unbiased, semi-automated HCI and CellProfiler histopathological analysis approach revealed regional and cell specific morphological signatures of immune and neural cells after stroke in a highly translational porcine model. These identified features can provide information of disease pathogenesis and evolution with high resolution, as well as be used in therapeutic screening applications.

Dorsal offset rhinoplasty for treatment of stenotic nares in 34 brachycephalic dogs

OBJECTIVE

To describe the technique, outcome, and owner satisfaction associated with dorsal offset rhinoplasty (DOR) to treat stenotic nares in brachycephalic dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Thirty-four client-owned dogs.

METHODS

Medical records of dogs treated with DOR at a veterinary teaching hospital over a 6-year period were identified. Dorsal offset rhinoplasty was defined as removal of a dorsal wedge of nasal planum from each naris with apposition of the rostral abaxial tissue to the caudal axial tissue, resulting in translocation of the alar cartilage in both median and dorsal planes. Immediate and postoperative complications were recorded. Owners were asked to report any complications with healing of the nares and to score their satisfaction with the appearance of the nares.

RESULTS

Thirty-four dogs met the inclusion criteria. Twenty-nine (85%) dogs were examined a median of 402.5 days (range, 23-2042) postoperatively, with no major complications related to the rhinoplasty recorded. Eighteen owners responded a median of 701 days (range, 37-1622) postoperatively. One owner reported that self-trauma led to collapse of one naris. One owner reported collapse of both nares within 4 years; timing and cause were unknown. Sixteen of 17 responding owners reported that they were very satisfied with the outcome of the rhinoplasty. The owner of the dog with the collapsed naris was very unsatisfied. One owner did not provide a satisfaction score.

CONCLUSION

Owners were generally highly satisfied with DOR, and complications were uncommon.

CLINICAL SIGNIFICANCE

This report describes an alternate technique to treat stenotic nares.

Characteristics and long-term outcomes of dogs with gastroesophageal intussusception

OBJECTIVE

To determine long-term outcomes and factors associated with those outcomes in dogs with gastroesophageal intussusception (GEI).

ANIMALS

36 dogs with GEI evaluated at 16 veterinary hospitals from January 2000 through January 2018.

PROCEDURES

Medical records of included dogs were reviewed to collect information regarding signalment, clinical signs, physical examination findings, blood work and diagnostic imaging results, surgical findings, and outcome. Factors were evaluated for associations with various outcomes.

RESULTS

Median age of dogs with GEI was 13.2 months, and males (72% [26/36]) and German Shepherd Dogs (33% [12/36]) were most common. Vomiting (67% [24/36]) and regurgitation (33% [12/36]) were the most common clinical signs. Ten of 36 (28%) dogs were euthanized without treatment, and 26 (72%) underwent treatment (25 surgically and 1 endoscopically). Twenty-three of the 26 (88%) treated dogs survived to discharge; median survival time was 995 days. At last follow-up, 15 of the 23 (65%) surviving dogs remained alive and 8 (35%) had died for reasons related to persistent regurgitation (n = 6) or reasons unrelated to GEI (2). Of the 10 dogs for which owners were contacted, 7 had persistent regurgitation, the severity of which was reduced through managed feedings. Dogs with acute (≤ 7 days) clinical signs or a previous diagnosis of megaesophagus were more likely to have persistent regurgitation than were dogs without these factors.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment should be considered for dogs with GEI given the high rate of survival to discharge and median survival time. Although persistent regurgitation was common after treatment, a satisfactory outcome was possible with medical management, including managed feedings and medications.

Evaluation of short-term outcomes and potential risk factors for death and intestinal dehiscence following full-thickness large intestinal incisions in dogs

OBJECTIVE

To determine complication rates for dogs in which full-thickness large intestinal incisions were performed, assess potential risk factors for death during hospitalization and for intestinal dehiscence following these surgeries, and report short-term mortality rates for these patients.

ANIMALS

90 dogs.

PROCEDURES

Medical records of 4 veterinary referral hospitals were reviewed to identify dogs that underwent large intestinal surgery requiring full-thickness incisions. Signalment, history, clinicopathologic data, medical treatments, surgical procedures, complications, and outcomes were recorded. Descriptive statistics were calculated; data were analyzed for association with survival to discharge (with logistic regression analysis) and postoperative intestinal dehiscence (with Fisher exact or Wilcoxon rank sum tests).

RESULTS

Overall 7-day postoperative intestinal dehiscence and mortality rates were 9 of 90 (10%) and 15 of 90 (17%). Dogs with preoperative anorexia, hypoglycemia, or neutrophils with toxic changes and those that received preoperative antimicrobial treatment had greater odds of death than did dogs without these findings. Preexisting colon trauma or dehiscence, preexisting peritonitis, administration of blood products, administration of > 2 classes of antimicrobials, positive microbial culture results for a surgical sample, and open abdominal management of peritonitis after surgery were associated with development of intestinal dehiscence. Five of 9 dogs with intestinal dehiscence died or were euthanized.

CONCLUSIONS AND CLINICAL RELEVANCE

Factors associated with failure to survive to discharge were considered suggestive of sepsis. Results suggested the dehiscence rate for full-thickness large intestinal incisions may not be as high as previously reported, but several factors may influence this outcome and larger, longer-term studies are needed to confirm these findings.

Histologic evaluation of mandibular and medial retropharyngeal lymph nodes during staging of oral malignant melanoma and squamous cell carcinoma in dogs

OBJECTIVE

To assess histologic evaluation of mandibular lymph nodes (MLNs) and medial retropharyngeal lymph nodes (MRLNs) for metastatic disease during tumor staging for dogs with oral malignant melanoma (OMM) and oral squamous cell carcinoma (OSCC).

DESIGN

Retrospective multi-institutional study.

ANIMALS

27 dogs with OMM and 21 dogs with OSCC.

PROCEDURES

Medical record databases of 8 institutions were searched to identify dogs with OMM or OSCC that underwent unilateral or bilateral extirpation of the MLNs and MRLNs during the same procedure between January 2004 and April 2016. Information extracted from the records included signalment, primary mass location and size, diagnostic imaging results, histologic results for the primary tumor and all lymph nodes evaluated, and whether distant metastasis developed.

RESULTS

Prevalence of lymph node metastasis did not differ significantly between dogs with OMM (10/27 [37%]) and dogs with OSCC (6/21 [29%]). Distant metastasis was identified in 11 (41%) dogs with OMM and was suspected in 1 dog with OSCC. The MRLN was affected in 13 of 16 dogs with lymph node metastasis, and 3 of those dogs had metastasis to the MRLN without concurrent metastasis to an MLN. Metastasis was identified in lymph nodes contralateral to the primary tumor in 4 of 17 dogs that underwent contralateral lymph node removal.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated histologic evaluation of only 1 MLN was insufficient to definitively rule out lymph node metastasis in dogs with OMM or OSCC; therefore, bilateral lymphadenectomy of the MLN and MRLN lymphocentra is recommended for such dogs.

Long-term outcome and risk factors associated with death or the need for revision surgery in dogs with permanent tracheostomies

OBJECTIVE

To evaluate long-term outcomes and identify factors associated with death or the need for revision surgery in dogs with permanent tracheostomies (PTs).

DESIGN

Retrospective cohort study.

ANIMALS

69 client-owned dogs that received a PT between January 2002 and June 2016 at 1 of 4 veterinary teaching hospitals.

PROCEDURES

Medical records were reviewed, and data extracted included signalment, history, clinical signs, radiographic and laryngeal examination findings, presence of esophageal abnormalities, date and reason for receiving a PT, postoperative complications, cause of death, and survival time. Dogs surviving < 2 weeks after receiving a PT were excluded.

RESULTS

Major complications occurred in 42 of 69 (61%) dogs, with aspiration pneumonia (13 [19%]), skinfold occlusion (13 [19%]), and stoma stenosis (12 [17%]) being most common. Revision surgery was performed in 24 of 69 (35%) dogs, most commonly because of stoma stenosis or skinfold occlusion (9/24 [38%] each). Brachycephalic dogs were more likely (OR, 3.5; 95% confidence interval, 1.2 to 10.2) to require revision surgery than were nonbrachycephalic dogs. The overall median survival time was 1,825 days, and dogs that received corticosteroids before receiving a PT, had tracheal collapse, or were older had shorter survival times.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of the present study indicated that creation of a PT was a viable treatment option for obstructive upper airway diseases in dogs and that long-term survival after receiving a PT was possible; however, a PT may not reduce the risk of aspiration pneumonia in dogs.

Outcomes associated with vaginectomy and vulvovaginectomy in 21 dogs

OBJECTIVE

To report the outcomes of dogs with lesions of the genitourinary tract treated by vaginectomy or vulvovaginectomy.

STUDY DESIGN

Multi-institutional retrospective study.

ANIMALS

Female dogs that underwent vulvovaginectomy, complete vaginectomy, or subtotal vaginectomy from 2003 to 2018 with complete medical records and a minimum of 60 days follow-up.

METHODS

Data collected from medical records included preoperative, intraoperative, and postoperative data, such as the occurrence of urinary incontinence (UIC), disease recurrence, and death/euthanasia.

RESULTS

This study included 21 dogs. Four dogs had vulvovaginectomy, six had complete vaginectomy, and 11 had a subtotal vaginectomy performed. The mean age at surgery was 9.2 years (SD, 3.3). Thirteen dogs were intact at presentation. Smooth muscle tumors were diagnosed most commonly (10 leiomyomata, three leiomyosarcomas, two leiomyofibromas). The median duration of follow-up was 520 days (range, 71-1955). Major complications requiring revision surgery were recorded in two dogs. Postoperative UIC occurred in six of 21 dogs, resolving spontaneously within 60 days in three dogs. Dogs with malignant tumors (n = 6) survived at least 71 days (median, 626; 95% CI, 71-1245), and recurrence of disease occurred in two dogs. In dogs with benign tumors (n = 15), the median survival time was not reached. These dogs survived at least 104 days and had no recurrence of the disease.

CONCLUSION

Vaginectomy and vulvovaginectomy resulted in prolonged survival and low rates of major complications and UIC.

CLINICAL SIGNIFICANCE

This study provides evidence to recommend that the risks of this procedure and expectations should be discussed with clients.

Clinical findings and outcomes of 153 dogs surgically treated for intestinal intussusceptions

OBJECTIVE

To describe perioperative characteristics and outcomes of dogs surgically treated for intestinal intussusception.

STUDY DESIGN

Multi-institutional, retrospective study.

ANIMALS

One hundred fifty-three client-owned dogs with intestinal intussusception.

METHODS

Dogs were included when they had undergone surgical treatment of a confirmed intestinal intussusception. Medical records were reviewed for demographics and clinical data, including surgical complications (graded 1-4). Follow-up was obtained via telephone interview with owners and referring veterinarians.

RESULTS

Dogs had a median age of 10 months (range, 2-156), and the most common location for intussusception was ileocolic (66/153 [43%]). Most cases had no identifiable cause (104/155 [67%]). Intestinal resection and anastomosis (IRA) was performed in 129 of 153 (84%) dogs; enteroplication was performed in 28 of 153 (18%) dogs, including 13 with and 15 without IRA. Intraoperative complications occurred in 10 of 153 (7%) dogs, all involving intestinal damage during attempted manual reduction. The median duration of follow-up after discharge was 334 days (interquartile range, 15-990; range, 1-3302). Postoperative complications occurred in 53 of 153 (35%) dogs, including 22 of 153 (14%) with severe (grade 3 or 4) events. Diarrhea, regurgitation, and septic peritonitis were the most common postoperative complications; intussusception recurred in four of 153 (3%) dogs, all within 72 hours postoperatively. Fourteen-day postoperative mortality rate was 6%.

CONCLUSION

Surgical treatment of intestinal intussusception was curative in most dogs, even when an underlying cause was not identified. Surgical complications were common, including a 14% risk of life-threatening short-term complications.

CLINICAL SIGNIFICANCE

Surgical treatment of intestinal intussusception offers an excellent prognosis, but the potential life-threatening complications should be considered.

Use of indirect computed tomography lymphangiography to determine metastatic status of sentinel lymph nodes in dogs with a pre-operative diagnosis of melanoma or mast cell tumour

Canine melanomas and mast cell tumours (MCTs) frequently metastasize to lymph nodes, worsening prognosis compared with dogs without metastasis. Sentinel lymph node (SLN) evaluation is more specific than evaluation of the lymph node closest to the tumour, which may not be the draining lymph node. Computed tomography lymphangiography (CTL) allows for SLN identification and one study of canine mammary tumours found that CTL was able to assist in determination of the metastatic status of inguinal SLNs prior to extirpation and histopathology. The objective of the present study was to evaluate CTL for use in determining metastasis to the SLN in dogs with a pre-operative diagnosis of melanoma or MCT in various locations by correlating CTL findings with histopathology. The hypothesis was that CTL would not be able to determine the metastatic status of lymph nodes, based on author experience. Dogs were prospectively enrolled and underwent CTL and subsequent SLN extirpation. Histopathology results for the primary tumour, SLN, and additional extirpated lymph nodes were recorded. Fifteen dogs were enrolled and 21 SLN were evaluated. The SLN enhancement pattern (heterogeneous, homogenous or peripheral) was not associated with metastasis, nor was the attenuation value at 1 minute, 5 minutes, or the change in attenuation value. No correlation was found between CTL findings and metastatic status of SLNs. Based on these results, CTL alone cannot be used to diagnose SLN metastasis. Extirpation of the SLN with histopathology is recommended to diagnose lymph node metastasis in dogs with melanoma and MCT.