Equine sarcoids: A clinicopathologic study of 49 cases, with mitotic count and clinical type predictive of recurrence

Sarcoids are common mesenchymal neoplasms of horses. Although there are few studies in which sarcoids have been followed over a long period of time, sarcoids are considered locally invasive and have been reported to frequently recur following surgical excision. Currently, no histological features have been identified to predict which sarcoids will recur after excision. The present study comprised 49 sarcoids for which histology sections were available and in which the recurrence status of the case was known. Each sarcoid was excised from a different horse. Overall, 12 of the 49 (24%) sarcoids recurred after surgical excision. Mitotic count (MC), cellularity, necrosis, nuclear pleomorphism, and inflammation of the sarcoids were evaluated histologically. Of these, MC correlated with recurrence. Four of 5 (80%) sarcoids with an MC ≥ 20 in 2.37 mm2 recurred, which was a significantly higher recurrence rate than that of sarcoids with an MC < 20, 8 of 44 cases recurred (18%), P = .0051. Clinical type was also found to correlate with recurrence. Three of 4 (75%) fibroblastic types recurred, which was a significantly higher recurrence rate than that of sarcoids with other clinical types, 9 of 45 cases (18%), P < .001. In addition, univariate Cox regression analysis confirmed fibroblastic type and MC ≥ 20 as significant predictors for recurrence (P = .016 and P = .005, respectively). To the authors' knowledge, this is the first large study examining recurrence rates in sarcoids, and the first time that histological features have been correlated with recurrence.

Novel Treatments for Lymphoma

Lymphoma is a common disease in companion animals. While conventional chemotherapy has the potential to induce remission and prolong life, relapse is common and novel treatments are needed to improve outcome. This review discusses recent modifications/adjustments to conventional standard of care therapy for canine and feline lymphoma, options for treatment or relapsed/refractory disease, and cutting-edge immunotherapy and small molecule-based approaches that are in varying stages of regulatory approval.

Updates in Surgical Oncology

New knowledge and data can influence the treatment options of dogs and cats affected by neoplasms. Partial limb amputation with the use of a prosthesis is possible in dogs. Newer studies attempt to define better and understand the complications and limb function associated with this approach. Limb sparing is an alternative to amputation, and three-dimensional printing allows the manufacturing of personalized endoprostheses. Finally, the recommended approach for the excision of cutaneous mast cell tumors (MCTs) is with proportional margins. In dogs, grade shifting might have occurred when removing a recurrent MCT or soft tissue sarcoma.

Malassezia dermatitis in dogs and cats

Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce a secondary Malassezia dermatitis, otitis externa or paronychia. Since allergic dermatitis is one of the most common underlying causes, diagnostic investigation for allergy is often indicated. Cats may suffer from various other underlying problems, especially where Malassezia dermatitis is generalised. Malassezia dermatitis in dogs and cats is chronic, relapsing and pruritic. Direct cytology from dermatological lesions and the ear canal, showing "peanut-shaped" budding yeasts, facilitates a rapid and reliable diagnosis. Topical treatment includes antiseptic and antifungal azole-based products. Systemic treatment with oral antifungals is indicated only in severe or refractory disease. Identification and treatment of the underlying cause is essential for an optimal response. In this evidence-based narrative review, we discuss the clinical presentation of Malassezia dermatitis in dogs and cats, underlying comorbidities, and diagnostic considerations. Treatment is discussed in light of emerging evidence of antifungal resistance and the authors' clinical experience.

Gene expression profiles associated with early relapse during first remission induction in canine multicentric high-grade B-cell lymphoma

Although chemotherapy using CHOP-based protocol induces remission in most cases of canine multicentric high-grade B-cell lymphoma (mhBCL), some cases develop early relapse during the first induction protocol. In this study, we examined the gene expression profiles of canine mhBCL before chemotherapy and investigated their associations with early relapse during the first whole CHOP-based protocol. Twenty-five cases of mhBCL treated with CHOP-based protocol as first induction chemotherapy were included in this study. Sixteen cases completed the first whole CHOP-based protocol without relapse (S-group), and nine developed relapse during the chemotherapy (R-group). RNA-seq was performed on samples from neoplastic lymph nodes. Differentially expressed genes (DEGs) were extracted by the comparison of gene expression profiles between S- and R-groups, and the differences in the expression levels of these genes were validated by RT-qPCR. Extracted 179 DEGs included the genes related to chemokine CC motif ligand, T-cell receptor signaling pathway, and PD-L1 expression and PD-1 checkpoint pathway. We focused on chemokine CC motif ligand, and CCL4 was confirmed to be significantly downregulated in the R-group (P=0.039). We also focused on the genes related to T-cell signaling pathway, and CD3E (P=0.039), ITK (P=0.023), and LAT (P=0.023) genes were confirmed to be significantly upregulated in the R-group. The current results suggest that both changes in tumor cells and the interactions between tumor cells and immune cells are associated with the efficacy of the chemotherapy for first remission induction.

Retrospective Evaluation of Melphalan, Vincristine, and Cytarabine Chemotherapy for the Treatment of Relapsed Canine Lymphoma

Dogs diagnosed with multicentric lymphoma often relapse following induction therapy within the first year of treatment. The primary aim of this study was to evaluate the tolerability of a novel drug combination using melphalan, vincristine, and cytarabine (MOC) for the treatment of relapsed lymphoma. On day 1, dogs were treated with vincristine (0.5-0.6 mg/m2 IV) and cytarabine (300 mg/m2 IV over 4-6 hr or subcutaneously over 2 days). On day 7, dogs were treated with melphalan (20 mg/m2per os). This 2 wk protocol was repeated for at least three cycles or until treatment failure. Twenty-six dogs were treated with MOC and met the inclusion criteria. Twenty-three dogs had toxicity data, and all experienced adverse events with the majority graded as mild. The overall response rate was 38%, which included 19% of dogs who achieved a complete response. The median progression-free survival was 29 days (range 1-280 days). The overall clinical benefit was 65% for a median of 37 days (range 33-280 days). MOC is a safe treatment option for relapsed lymphoma in dogs.

Evaluation of the clinical outcome of hypercalcemia of malignancy and concurrent azotemia in dogs with lymphoma

BACKGROUND

Hypercalcemia of malignancy (HM) secondary to lymphoma in dogs has the potential to cause renal injury.

HYPOTHESIS/OBJECTIVES

Characterize outcomes related to acute kidney injury (AKI) secondary to HM. We hypothesized that dogs do suffer AKI regardless of HM severity at the time of lymphoma diagnosis or relapse.

ANIMALS

Retrospective study. Twenty-nine dogs with lymphoma, HM, and azotemia (International Renal Interest Society [IRIS] grade II or higher AKI) that underwent chemotherapy were identified at 2 veterinary institutions.

METHODS

Logistic regression and descriptive statistical analysis were performed to evaluate data for potential prognostic factors.

RESULTS

After initiating treatment, resolution of hypercalcemia and azotemia occurred in 100% (29/29) and 79.3% (23/29) of dogs, respectively. Resolution of azotemia was influenced by serum creatinine concentration (odds ratio [OR], 0.148; Confidence interval [CI], 0.03-0.734; P = .02) and total hypercalcemia (OR, 0.36; CI, 0.14-0.93; P = .04) at diagnosis, whereas blood urea nitrogen concentration, IRIS grade, sex, and whether or not dogs were hospitalized were not significant factors. At data analysis, 13.8% (4/29) of dogs were alive or lost to follow-up. Of those dead, 4 dogs (15%) had renal disease at the time of death, 2/4 having concurrent lymphoma progression.

CONCLUSIONS AND CLINICAL IMPORTANCE

Although AKI may be of clinical concern in dogs with HM secondary to lymphoma at diagnosis, death secondary to renal impairment appears to be infrequent.

Successful Surgical Resection of an Ependymal Cyst in the Fourth Ventricle of a Dog

Ependymal cysts represent congenital brain malformations rarely described in human medicine, where surgical resection is the treatment of choice. In veterinary medicine, only three cases have been previously reported, with one partially resected with surgery. A 6 yr old entire male American Staffordshire terrier was referred with a 4 mo history of incoordination and collapsing episodes with extensor rigidity. Neurological examination localized the lesion to the left central vestibular system and cerebellum. A brain computed tomography scan showed a hypoattenuating lesion with peripheral contrast enhancement in the fourth ventricle consistent with a cyst and secondary hydrocephalus. Treatment with prednisone was initiated, but despite an initial improvement, neurologic signs recurred and a suboccipital craniectomy to remove the cyst was performed. The cyst was first drained, and the capsule was carefully resected. The histopathological evaluation revealed a simple cubic to cylindrical epithelium with apical cilia and loose surrounding fibrillar tissue consistent with an intraventricular ependymal cyst. Four and a half years after surgery, the dog only shows short episodes of balance loss when turning abruptly but is otherwise neurologically normal. To the authors' knowledge, this is the first reported ependymal cyst in the fourth ventricle of a dog with successful surgical resection.

Prognostic factors and outcome in cats with thymic epithelial tumours: 64 cases (1999-2021)

OBJECTIVES

To describe the clinical presentation, treatment and outcomes of cats diagnosed with thymic epithelial tumours and to determine prognostic factors for survival and recurrence.

MATERIALS AND METHODS

Clinical records of cats diagnosed with a thymic epithelial tumour between 1999 and 2021 at three referral institutions were retrospectively reviewed.

RESULTS

Sixty-four cats were included. Paraneoplastic syndromes were present in nine cats and metastatic disease was seen in two cats, one at diagnosis and one at the time of recurrence. Median tumour diameter was 6 cm (range, 2 to 15) and a cystic appearance was described on imaging in 25 cats. Surgical excision was attempted in 54 cats with a perioperative mortality rate of 11%. Median survival time for cats surviving to hospital discharge was 897 days (range, 21 to 3322). The 1-, 2- and 5-year survival rates for surgically treated thymic epithelial tumour were 86%, 70% and 66%, respectively. Survival was longer for cats with Masaoka-Koga stage I and II tumours compared to stages III and IV (1366 days versus 454 days; P=0.002). Masaoka-Koga stage was the only significant prognostic factor detected on multi-variable analysis, with stage III and IV tumours associated with increased risk of death (hazard ratio: 5.67, 95% confidence interval: 1.29 to 24.91, P=.021). Tumour recurrence occurred in 11 cats at a median of 564 days (range, 93 to 1095); no significant prognostic factors for recurrence were identified.

CLINICAL SIGNIFICANCE

Cats with thymic epithelial tumours had a good long-term prognosis following surgery. Tumour recurrence can occur late in the disease course and ongoing monitoring should therefore be considered. Masaoka-Koga stage may influence survival time and could be used to predict outcome.

Capillary gingival hemangioma in a cat

A 12-year-old spayed female American short-haired cat presented with a palatal gingival mass located between the right maxillary third incisor and the canine teeth. The mass was dark red and had a narrow attachment to the gingival margin of the canine tooth. The mass was completely removed by marginal excision and the histopathological diagnosis was a capillary hemangioma. The mass did not relapse until 1 year later; however, the tooth was extracted because of cervical resorption of the right maxillary canine immediately adjacent to the mass resection site. This report presents a rare case of the gingival hemangioma in a cat and the possibility of a causal relationship between the occurrence of external cervical tooth resorption and hemangioma resection.

Laparoscopic adrenalectomy for resection of unilateral noninvasive adrenal masses in dogs is associated with excellent outcomes in experienced centers

OBJECTIVE

To report the short- and long-term outcomes of laparoscopic adrenalectomy (LA) for resection of unilateral adrenal masses and to document risk factors for conversion and peri- and postoperative morbidity.

ANIMALS

255 client-owned dogs.

METHODS

Dogs were included if LA was attempted for resection of a unilateral adrenal mass. Medical records were evaluated and relevant data were reported, including complications, conversion, perioperative death, and long-term outcomes. Signalment, clinicopathological data, and surgical experience were factors statistically evaluated for possible associations with capsular penetration during surgery, conversion, surgical time, duration of hospital stay, death prior to discharge, mass recurrence, and survival time.

RESULTS

155 dogs had left-sided tumors, and 100 had right-sided tumors. Conversion to an open approach was performed in 9.4% of cases. Capsular penetration (19.2%) and major hemorrhage (5.4%) were the most prevalent intraoperative complications. Of the dogs operated on, 94.9% were discharged from the hospital. Lesion side, portion of the gland affected, and surgeon experience influenced surgical time. Conversion rate increased with increasing body condition score and lesion size. Risk of death prior to discharge increased with increasing lesion size. Risk of conversion and death prior to discharge were lower when performed by more experienced surgeons. Capsular penetration during LA increased the risk of tumor recurrence.

CLINICAL RELEVANCE

LA for resection of unilateral adrenal masses is associated with excellent outcomes in experienced centers. Surgeons with greater experience with LA have lower surgical times, conversion rates, and risk of death prior to discharge.

A modified full-thickness labial/buccal rotational flap reconstruction technique following bilateral rostral maxillectomy and nasal planectomy for resection of maxillary tumors: Technique and results in two dogs

OBJECTIVE

To describe a naso-facial reconstruction technique following bilateral rostral maxillectomy and its functional and cosmetic outcomes.

ANIMALS

Two dogs.

STUDY DESIGN

Clinical case series.

METHODS

Two dogs were presented with a right rostral maxillary mass. Preoperative biopsy and staging revealed a biologically high-grade and histologically low-grade fibrosarcoma (Hi-Lo FSA). A combined nasal planectomy and radical bilateral rostral maxillectomy was performed sparing the labial/buccal mucocutaneous flaps bilaterally. Surgery resulted in asymmetry of the width of the flaps; the narrower flap was rotated medially to reconstruct the lip and create an oral vestibule. The wider flap was rotated medially to cover the remaining dorsolateral opening of the nasal conchae. The flaps overlapped in a parallel manner, discretely concealing the nasal passages, and separating them from the oral cavity. Hemorrhage occurred in both dogs, with one dog requiring a blood transfusion postoperatively.

RESULTS

Oral Hi-Lo FSA with tumor-free margins was confirmed in both dogs. Both dogs recovered uneventfully within 4 weeks. Owners reported being very satisfied with the functional (return to normal exercise/activities and uncompromised respiration) and cosmetic outcomes. Based on the owners' telephone follow up, no tumor recurrence was noted at 15 (Dog 1) and 6 (Dog 2) months postoperatively.

CONCLUSION

The full-thickness bilateral labial/buccal rotational flaps were used successfully to reconstruct the rostral maxilla, external nose and facial defects involving the nasal cavity. The technique resulted in acceptable functional and cosmetic outcomes and can be considered for naso-facial reconstruction in selected cases.

Long-term outcomes associated with a modified versus traditional closed anal sacculectomy for treatment of canine anal sac neoplasia

OBJECTIVE

To report the short-term and long-term outcomes of dogs that underwent the modified closed and traditional closed anal sacculectomy procedures for the treatment of anal sac neoplasia.

ANIMALS

90 client-owned dogs.

Methods

The medical records of 2 tertiary referral hospitals were reviewed to identify dogs that underwent anal sacculectomy for treatment of anal sac neoplasia between January 2016 and December 2020. Data collected included signalment and preoperative diagnostic findings. The occurrence of intraoperative and postoperative complications, short-term outcomes, and long-term outcomes were also collected. Descriptive statistics were calculated to summarize dog signalment information, and recurrence, metastasis, and survival proportions were compared between techniques using Fisher exact tests.

RESULTS

35 and 55 dogs, respectively, underwent the modified or traditional closed anal sacculectomy procedure. Minor postoperative complications that resolved with minimal intervention occurred in 5 of 35 (14.3%) modified approach dogs and 12 of 55 (21.8%) traditional approach dogs. Tumor recurrence was confirmed in 8 of 35 (22.9%) modified and 8 of 55 (26.4%) traditional approach dogs and was suspected in 3 of 35 (8.6%) and 6 of 55 (13.2%; P = .68), respectively. Confirmed metastatic disease was identified in 8 of 35 (22.9%) and 14 of 53 (26.4%) modified and traditional approach dogs, respectively, and was suspected in 4 of 35 (11.4%) and 7 of 53 (13.2%). Sixty-three (70%) dogs survived to study conclusion.

CLINICAL RELEVANCE

No benefits in complication rate or local recurrence were identified in dogs following the modified approach as opposed to the traditional closed anal sacculectomy technique.

Diagnosis and Surgical correction of salivary affections in buffaloes (Bubalus bubalis); a retrospective study

AIM

This study aimed to describe the diagnosis and treatment of various surgical salivary affections in buffaloes.

MATERIALS AND METHODS

This study included 135 buffaloes examined at Dakahlia Governorate between 2011 and 2022 suffering from various surgical salivary affections. The recorded surgical affections had salivary fistula (n = 44), ectasia of Stenson's duct (n = 11), ranula/mucocele (n = 46), and cervical sialocele (n = 34). The buffaloes were sedated using an intramuscular injection of xylazine (0.05 mg/kg) and local infiltration analgesia of lidocaine for specific surgical interventions.

RESULTS

The salivary duct fistula cases were surgically corrected using a retrograde infusion of povidone-iodine into the duct and its double ligation with Prolene following fistulectomy. Intraoral marsupialization was done in buffaloes suffering from ectasia of the parotid duct. The mucocele /ranula was surgically incised with daily flushing with povidone-iodine. The cervical sialocele was treated by giving an elliptical excision on the sialocele, and sialoadenectomy of the mandibular salivary gland was performed to facilitate dynamic fluid/saliva drainage. A 92.5% of diseased buffaloes showed an uneventful recovery without any postoperative complications after the first treatment, whereas 7.5% of animals tended to recur. The most common and almost equally distributed salivary affections recorded in adult buffaloes were parotid duct fistula, mucocele, and cervical sialocele. The Stenson's duct ectasia was commonly registered in calves, being congenital.

CONCLUSION

Ranula was the most common salivary affection encountered in adult buffaloes, closely followed by parotid duct fistulae and cervical sialoceles. Stenson's duct ectasia was the least encountered salivary affection in calves and was congenital. All salivary affections were corrected easily and safely, with satisfactory outcomes.

Central and left division hepatectomies in two dogs

OBJECTIVE

To describe the management of extensive hepatectomy in 2 dogs.

ANIMALS

A 10-year-old female intact mixed-breed dog (case 1) and an 11-year-old male castrated mixed-breed dog (case 2) were presented for surgical evaluation following diagnosis of a hepatic mass.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

16 months before presentation, case 1 had undergone a left lateral liver lobectomy, which resulted in an incomplete resection of hepatocellular carcinoma. Both dogs underwent surgical excision of the liver mass.

TREATMENT AND OUTCOME

In case 1, surgery consisted of the removal of the remaining left medial lobe, as well as the central division. Case 2 received a complete left and central division hepatectomy. Histopathology confirmed a diagnosis of hepatocellular carcinoma in both dogs. Liver enzyme resolution and lack of tumor recurrence were confirmed with chemistry panel and abdominal ultrasonography in both dogs.

CLINICAL RELEVANCE

This case report describes, for the first time, the clinical management and outcome of extensive hepatectomy in 2 dogs. We propose that extensive hepatectomy, staged or synchronous, is possible in a clinical setting.

Single high-dose radiation therapy and liquid fiducial markers can be used in dogs with incompletely resected soft tissue sarcomas

OBJECTIVE

To evaluate the outcome and effects of single high-dose radiation therapy with the aid of liquid fiducial markers in dogs following resection of soft tissue sarcomas (STSs).

ANIMALS

36 client-owned dogs.

METHODS

Dogs with a histologic diagnosis of a grade II or III STS that underwent liquid fiducial guided single fraction, 20-Gy stereotactic radiation therapy following surgical excision of an STS between May 2017 and March 2019 were prospectively enrolled in this study. Data collected from the medical records included patient signalment, tumor-related information, treatment details, and outcome. Kaplan-Meier survival analysis was performed for overall survival time (OST) and disease-free interval (DFI). The median OST and DFI were not reached, so restricted mean OST and DFI were also calculated.

RESULTS

36 dogs were included in the study. All dogs underwent radiation therapy a mean of 36.1 days (range, 20 to 59 days) after surgery. Acute and delayed radiation toxicity effects occurred in 80.5% and 36.1% of dogs, respectively, all of which affected the skin. Tumor recurrence was noted in 24.3% of dogs with a median time to recurrence of 272 days (range, 14 to 843 days). The restricted mean OST was 1,556 days (range, 1,383 to 1,728 days) and restricted mean DFI was 1,330 days (range, 1,101 to 1,559 days).

CLINICAL RELEVANCE

The results of this study showed that administering a single 20-Gy fraction of radiation in combination with a liquid fiducial marker to treat marginally or incompletely resected STS in the absence of gross disease resulted in similar OST and DFI compared to other previously reported radiation protocols.

Acellular fish skin may be used to facilitate wound healing following wide surgical tumor excision in dogs: a prospective case series

OBJECTIVE

To prospectively evaluate clinical outcomes using acellular fish skin grafts (FSGs) for the management of complete wound healing by secondary intention after wide surgical excision of skin tumors in dogs.

ANIMALS

5 dogs undergoing wide surgical excision of skin tumors on the distal extremity.

CLINICAL PRESENTATION AND PROCEDURES

FSGs were applied to surgical wound beds following wide excision of the tumor. Bandages were changed weekly and additional grafts placed when integration of the previous graft was complete. The wounds were assessed for the following: dimensions, tissue health (color), time to complete epithelialization, complications, and tumor recurrence.

RESULTS

All masses were excised with 2-cm lateral margins and 1 fascial plane deep to the tumor. Tumor diagnoses included 3 mast cell tumors and 2 soft tissue sarcomas. Surgical wounds had a median area of 27.6 cm2 (range, 17.6 to 58.7 cm2). The median number of FSG applications was 5 (range, 4 to 9 applications). Complete epithelialization occurred within 7 to 9 weeks for uncomplicated wounds (3 of 5) and 12 to 15 weeks for complicated wounds (2 of 5) that sustained self-trauma. There were no adverse events related to the use of FSGs. Local recurrence was not seen over a follow-up period ranging from 239 to 856 days.

CLINICAL RELEVANCE

Wide surgical excision of distal extremity skin tumors, followed by repeated application of acellular FSGs, resulted in complete healing of all wounds with no adverse events. This treatment method does not require advanced reconstructive surgical skills and may be useful for the management of skin tumors on the distal extremities.

Mammary carcinoma: Comparative oncology between small animals and humans-New therapeutic tools

The poor outcomes associated with mammary carcinomas (MCs) in dogs and cats in terms of locoregional recurrence, distant metastasis and survival, highlight the need for better management of mammary cancers in small animals. By contrast, the outcomes of women with breast cancer (BC) have dramatically improved during the last 10 years, notably thanks to new therapeutic strategies. The aim of this article was to imagine what could be the future of therapy for dogs and cats with MCs if it became inspired from current practices in human BC. This article focuses on the importance of taking into account cancer stage and cancer subtypes in therapeutic plans, on locoregional treatments (surgery, radiation therapy), new developments in endocrine therapy, chemotherapy, PARP inhibitors and immunotherapy. Ideally, multimodal treatment regimens would be chosen according to cancer stage and cancer subtypes, and according to predictive factors that are still to be defined.

Evaluation of mechlorethamine, vinblastine, procarbazine, and prednisone for the treatment of resistant multicentric canine lymphoma

Multi-agent chemotherapy successfully induces remission in most naïve, high-grade canine lymphoma patients; however, disease recurrence is common. MOPP (mechlorethamine, vincristine, procarbazine, and prednisone) is an effective rescue protocol used to re-induce remission, but is associated with gastrointestinal toxicity and can be a less desirable option for patients that previously failed vincristine-containing protocols. Therefore, alternative members of the vinca alkaloid family, such as vinblastine, could be potentially advantageous as substitutes for vincristine to reduce gastrointestinal toxicity and chemoresistance. The objective of this study was to report the clinical outcomes and toxicity of 36 dogs with relapsed or refractory multicentric lymphoma treated with a modified MOPP protocol whereby vincristine was replaced with vinblastine (MVPP). The overall response rate to MVPP was 25% with a median progression free survival of 15 days and a median overall survival of 45 days. MVPP at the prescribed doses resulted in modest and transient clinical benefit, but was well tolerated with no treatment delays or hospitalizations secondary to side effects. Given the minimal toxicity, dose intensification could be considered to improve clinical responses.

A case of spermatic cord B-cell lymphoma relapsing to the brain in a dog

A 13-year-old, intact male mixed-breed dog was referred to our clinic for lethargy and asthenia following an episode of gastroenteritis. As an incidental finding during abdominal ultrasound, a mass on the right spermatic cord was seen. Cytology of the mass revealed a monomorphic population of large, round cells with a lymphoid appearance. A bilateral orchiectomy was conducted, and histopathology revealed the presence of a B-cell lymphoma in the right spermatic cord. Based on clinical staging, which showed no involvement of other sites, no additional treatment was administered. Recheck evaluations were scheduled for every 3 mo thereafter. Five months after surgery, the dog developed left central vestibular syndrome with a paradoxical right-sided head tilt. An MRI of the brain showed multifocal lesions and, due to a rapidly worsening clinical condition, the dog was humanely euthanized. The histopathology of the brain lesions was consistent with B-cell lymphoma. Key clinical message: This is the first report of a primary spermatic cord lymphoma relapsing to the brain in a dog. Although rare, spermatic cord tumors should be included among the differential diagnoses for masses arising from the spermatic cord. If lymphoma is diagnosed, location to other sites, especially to the central nervous system, should be considered.

A case of colonic-colonic intussusception in a dog secondary to lymphoma treated with colonic resection and anastomosis

A 2-year-old castrated male Great Dane crossbreed dog was presented with a history of diarrhea and suspected intussusception. Abdominal ultrasound revealed a colonic-colonic intussusception. The gastrointestinal tract was explored, and an approximately 5-cm intussusception was discovered mid-colon. All other gastrointestinal structures were normal in appearance. The intussusception could not be reduced manually. A colonic resection and anastomosis were performed together with a left-sided incisional colopexy. The dog recovered from surgery and histopathology revealed the intussusception to be secondary to large cell transmural lymphoma. Sections from the surgical margins revealed proliferation of fibrovascular tissue along the serosal surface segmentally, but no neoplastic cells were identified. The dog was subsequently treated with chemotherapy consisting of doxorubicin and prednisone. No evidence of disease recurrence was noted on ultrasound 9 months after surgery. Approximately 2 years after surgery, the dog is noted to be clinically normal at home with no abnormal findings on physical examination. A complete blood (cell) count and chemistry obtained at this time revealed no significant abnormalities besides mild azotemia. Additional restaging was declined by the owner.

Minimal complications observed with a modified surgical approach for treatment of canine anal sac neoplasia

OBJECTIVE

To describe a modified approach to closed anal sacculectomy and report the short-term outcomes of dogs that underwent the procedure for treatment of neoplasia.

ANIMALS

16 client-owned dogs.

PROCEDURES

Medical records of 1 referral hospital were reviewed to identify dogs that underwent modified closed anal sacculectomy for treatment of anal sac neoplasia between January 2018 and September 2020. Data collected included signalment, examination and diagnostic imaging findings, surgical details, intraoperative and postoperative complications, cytologic and histologic findings, adjuvant treatments, duration of follow-up, and short-term outcome.

RESULTS

15 dogs had apocrine gland anal sac adenocarcinoma, and 1 had a collision tumor. No dogs had intraoperative complications; 1 dog had a minor postoperative complication (paraparesis) that resolved. The median duration of postoperative follow-up was 286 days (range, 67 to 777 days). One dog had confirmed local disease recurrence 290 days after surgery, and 1 had suspected local disease recurrence 203 days after surgery and was euthanized because of systemic disease progression.

CONCLUSIONS AND CLINICAL RELEVANCE

The modified closed anal sacculectomy was well tolerated in this sample of dogs, with minimal short-term complications. This study provided evidence to justify evaluation of the procedure in a larger number of dogs and assessment of the effects of procedural modifications on postoperative complication rates and time to local recurrence.

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.

Laparoscopic resection of retroperitoneal paraganglioma close to caudal vena cava in a dog

OBJECTIVE

To report laparoscopic resection of retroperitoneal paraganglioma close to the caudal vena cava in a dog.

STUDY DESIGN

Case report.

ANIMAL

Twelve-year-old, neutered male Jack Russell terrier.

METHODS

The dog had undergone three previous cystotomies for bladder stones. On follow-up ultrasonographic evaluation, a 14-mm × 17-mm tumour was incidentally detected in the dorsal midline of the caudal abdomen. The dog underwent computed tomography (CT) imaging and ultrasound-guided fine needle aspiration of the tumour under general anaesthesia. CT imaging showed that the tumour was close to the caudal vena cava. There was no evidence of metastasis. Neuroendocrine tumour was suspected on cytologic examination. Based on these findings, laparoscopic tumour resection was performed using a vessel-sealing device. The operation time was 136 minutes.

RESULTS

The dog was stable after recovery from anaesthesia and discharged to home the next day. Histopathological diagnosis of the tumour was a paraganglioma. The dog remained without clinical evidence of recurrent tumour or metastasis for 670 days after the surgery.

CONCLUSION

Retroperitoneal paraganglioma in dogs is uncommon, but it is one of the differential diagnoses of a retroperitoneal tumour. Laparoscopic resection of a retroperitoneal paraganglioma was successfully performed in the dog. Laparoscopic resection conferred the advantages over open surgery of being minimally invasive, providing better visualization of the surgical field through pneumoperitoneum and semisternal patient recumbency, and allowing for magnification of the operative field, which facilitated the ease and safety of the procedure.

Lateral canthal fibroma in a dog

A 9-year-old castrated male pitbull dog was presented for evaluation of a subconjunctival swelling of 10 days duration. On ophthalmic examination, a subcutaneous mass was identified at the right lateral canthus. An excisional biopsy was performed, and histopathological analysis confirmed a diagnosis of a subcutaneous fibroma. Eleven months after surgical excision, the dog had no evidence of recurrence. Fibroma should be included in the differential diagnosis of rapidly enlarging eyelid masses.

Zygomatic sialocele secondary to infarction treated with sialoadenectomy in a dog

Zygomatic salivary gland disease is not commonly reported in dogs and there is a paucity of literature reporting salivary gland disease secondary to infarction in dogs. A 9-year-old German wirehaired pointer presented with left eye exophthalmos, 3rd eyelid elevation, negative retropulsion, and pain upon opening of the mouth. Computed tomography revealed a mass extending from the left zygomatic salivary gland, consistent with a sialocele. A left-sided zygomatic sialoadenectomy was performed successfully. Histopathologic diagnosis concluded zygomatic salivary gland infarction. The dog had no signs of recurrence 20 mo after surgery. Key clinical message: To the authors' knowledge, this is the first case report with long-term outcome of a zygomatic sialocele secondary to salivary gland infarction in a dog treated by zygomatic sialoadenectomy via zygomatic osteotomy.

Outcome of a dog with urinary bladder osteosarcoma treated with a total cystectomy and ureterocutaneostomy

A 10-year-old, neutered female, French bulldog was presented with a history of dysuria, hematuria, stranguria, and pollakiuria. Diagnostic tests revealed a large mass at the neck of the bladder without any evidence of metastatic disease. Total cystectomy with bilateral cutaneous ureterostomy creation was elected. Histopathology of the bladder mass revealed extraskeletal osteosarcoma, which was resected completely. Neither recurrence nor metastasis had been detected as of 65 months after surgery. Extraskeletal osteosarcomas are typically malignant and carry a poor prognosis. This is the first report of bladder osteosarcoma in a dog treated by total cystectomy and ureterocutaneostomy with excellent long-term control.

Recurrence analysis of intraoperative acridine orange-photodynamic therapy for dogs with intranasal tumors

Intraoperative acridine orange-photodynamic therapy (AO-PDT) and cribriform plate irradiation are used to treat canine intranasal tumors. The purpose of this study was to evaluate the effects of AO-PDT on intranasal tumors and the recurrence rate of tumors after this treatment. Treatments with AO-PDT were performed on 38 dogs through a narrow window of the dorsal nasal cavity. The median progression-free interval was 12 mo and recurrence was detected in 21 dogs. Based on computed tomography, recurrence in 16 dogs was biased to the following areas: lateral (n = 10), medial (n = 2), ventral (n = 0), rostral (n = 0), and caudal (n = 8). Side effects were mild and included subcutaneous emphysema and rhinitis. The median survival time was 24 mo. Although AO-PDT with cribriform irradiation is an effective treatment for intranasal tumors, AO-PDT techniques should be improved to treat the nasal cavity more uniformly and thoroughly.

Transoral approach for mandibular and sublingual sialoadenectomy in a cat

Sialocele is an uncommon condition in cats. The treatment of choice for sublingual sialocele is excision of the ipsilateral mandibular and sublingual salivary gland/duct complex. Lateral and ventral cervical approaches have been described for mandibular-sublingual sialoadenectomy; however, the transoral approach, described here, has never been reported in cats. Ranula in the present case was likely caused by an inadvertent trauma of the sublingual duct during resection of a sublingual lesion performed by the referring veterinarian. The definitive surgery consisted of mass removal and sialoadenectomy through a unique oral approach. The surgery was effective without complications encountered after 6 months of follow-up. Key clinical message: This article reports a novel, transoral approach, for mandibular and sublingual sialoadenectomy in the cat. This approach decreases the surgical time and prevents recurrence of the mucocele.

Clinical features, treatment, and outcome of aural hematomas in horses: 7 cases (2008-2019)

OBJECTIVE

To characterize the clinical features, treatment, and outcome of aural hematomas in horses.

ANIMALS

7 horses with 1 or 2 aural hematomas (8 ears in total) treated at a veterinary teaching hospital in 2008 through 2019.

PROCEDURES

Data retrieved from medical records included signalment, pertinent historical information, clinical signs, diagnostic procedures (including dermatologic assessment), and treatments. Case outcome was determined from documentation in the medical record or via telephone communication with owners or referring veterinarians.

RESULTS

3 horses were presented after recurrence of aural hematoma following treatment by the referring veterinarian. Four horses had a history of allergic skin disease prior to aural hematoma development. Most (6/7) horses were unilaterally affected. Diagnostic assessments included otoscopic evaluation (3 horses), ultrasonography (3 horses), cytologic examination of ear canal swab samples (3 horses), and histologic examination of a pinnal biopsy specimen (1 horse). Of the 8 pinnae, 2 were treated by nonsurgical needle drainage (1 with concurrent corticosteroid injection) and the remaining 6 underwent surgical incision and placement of compressive sutures. Follow-up information was available for 6 horses, and all affected pinnae were fibrotic with 4 horses having permanent drooping of the pinna. One horse developed a hematoma in the contralateral pinna 1 year after hospital discharge.

CONCLUSIONS AND CLINICAL RELEVANCE

Equine aural hematoma is a rare condition. The main principle of treatment is drainage, and treatment options commonly used in small animal practice can be successfully applied in horses. Permanent changes in the cosmetic appearance of the pinna are likely to develop owing to secondary fibrosis.

Ovarian remnant syndrome in a cat with ovarian tissue in the omentum

CASE DESCRIPTION

A 2-year-old spayed female domestic shorthair cat was evaluated for recurring estrous behavior after ovariohysterectomy and 2 subsequent exploratory laparotomies.

CLINICAL FINDINGS

Physical examination revealed no abnormalities. A serum sample tested positive for anti-Müllerian hormone and had a progesterone concentration consistent with the presence of an ovarian remnant. Results of abdominal ultrasonographic examination suggested presence of a slightly hyperechoic mass caudal to the left kidney.

TREATMENT AND OUTCOME

Exploratory laparotomy was performed when the cat was showing estrous behavior. Tissues at the right and left ovarian pedicles and the uterine stump appeared grossly normal but were excised and submitted for histologic examination. Two small nodules associated with the omentum were removed, and histologic examination results for one of these nodules indicated ovarian tissue with secondary and graafian follicles. Clinical signs of estrus resolved after surgery, and hormonal assay results were within ranges expected for an ovariectomized cat.

CLINICAL RELEVANCE

To the authors' knowledge, the present case represented the first clinical report of ovarian remnant syndrome in a cat or dog in which persistent ovarian tissue was not found at the site of an ovarian pedicle. Our findings emphasized the importance of exploring the entire abdominal cavity when evaluating a patient for possible ovarian remnant tissue and confirming the excision of ovarian remnant tissue by histologic assessment.

Iridociliary adenoma in a greater sulfur-crested cockatoo (Cacatua galerita galerita)

A 34-year-old female greater sulfur-crested cockatoo (Cacatua galerita galerita) was referred for suspected left globe rupture. Ophthalmic examination revealed effacement of the anterior chamber and cornea by a large mass. The left eye was enucleated due to suspicion of globe rupture, secondary to a neoplastic process or chronic trauma. Histopathological examination revealed complete effacement of the internal ocular structures by a neoplasm morphologically consistent with an iridociliary adenoma. The diagnosis was confirmed by Periodic acid-Schiff histochemistry and immunohistochemistry for S100, Melan-A/PNL2, and vimentin antigens. The cockatoo recovered well from surgery, with appropriate healing of the enucleation site, and no evidence of recurrence at 1-year follow-up. Key clinical message: To the authors' knowledge, this is the first report of iridociliary adenoma in a greater sulfur-crested cockatoo, and the third report of such a neoplasm in a psittacine species with a description of the use of immunohistochemistry to confirm a diagnosis of a rare tumor in a bird species.

Molecular characterization of a marine turtle tumor epizootic, profiling external, internal and postsurgical regrowth tumors

Sea turtle populations are under threat from an epizootic tumor disease (animal epidemic) known as fibropapillomatosis. Fibropapillomatosis continues to spread geographically, with prevalence of the disease also growing at many longer-affected sites globally. However, we do not yet understand the precise environmental, mutational and viral events driving fibropapillomatosis tumor formation and progression.Here we perform transcriptomic and immunohistochemical profiling of five fibropapillomatosis tumor types: external new, established and postsurgical regrowth tumors, and internal lung and kidney tumors. We reveal that internal tumors are molecularly distinct from the more common external tumors. However, they have a small number of conserved potentially therapeutically targetable molecular vulnerabilities in common, such as the MAPK, Wnt, TGFβ and TNF oncogenic signaling pathways. These conserved oncogenic drivers recapitulate remarkably well the core pan-cancer drivers responsible for human cancers. Fibropapillomatosis has been considered benign, but metastatic-related transcriptional signatures are strongly activated in kidney and established external tumors. Tumors in turtles with poor outcomes (died/euthanized) have genes associated with apoptosis and immune function suppressed, with these genes providing putative predictive biomarkers.Together, these results offer an improved understanding of fibropapillomatosis tumorigenesis and provide insights into the origins, inter-tumor relationships, and therapeutic treatment for this wildlife epizootic.

Lateral rhinotomy and coblation for treatment of a nasal hamartoma in a dog

CASE DESCRIPTION

A 4-year-old spayed female French Bulldog was referred for treatment of a suspected right-sided nasal angiofibroma associated with a 4-month history of unilateral nasal discharge and stertor.

CLINICAL FINDINGS

The dog appeared healthy other than right-sided mucoid debris and decreased airflow through the right naris. The dog was anesthetized, and a large intranasal mass was observed obstructing the right nasal passage and abutting the nasal septum.

TREATMENT AND OUTCOME

A lateral rhinotomy was performed, and rigid endoscopes (0° and 30°) were used to examine the right nasal cavity. The mass filled the anterior aspect of the nasal cavity and involved a portion of the nasal turbinates with some erosion. A coblation unit was used to ablate tumor tissue laterally to remove the tumor in piecemeal fashion. Recovery was routine with only minor epistaxis after surgery, and the dog was discharged the next day. Eight months after surgery, follow-up CT revealed right-sided nasal turbinate and conchal atrophy consistent with prior mass ablation. No macroscopic recurrence was detected, and the owners reported only rare, clear rhinorrhea.

CLINICAL RELEVANCE

Findings suggested that coblation may be an alternative to radiation therapy for vascular tumors with minimal invasion and low metastatic potential.

Clinical and serologic remission of acquired myasthenia gravis in a domestic ferret (Mustela putorius furo)

CASE DESCRIPTION

A 4.5-year-old neutered male domestic ferret (Mustela putorius furo) was examined because of clinical signs compatible with neuromuscular disease.

CLINICAL FINDINGS

Results of electrophysiologic assessment, including measurement of compound muscle action potentials following repetitive nerve stimulation, and measurement of the anti-acetylcholine receptor antibody titer were consistent with a diagnosis of acquired myasthenia gravis.

TREATMENT AND OUTCOME

Medical treatment with pyridostigmine and prednisolone was instituted. The first signs of clinical improvement were observed 2 months later, followed by a slow but steady improvement over the next months. Anti-acetylcholine receptor antibody titer was measured 10 months after initiation of treatment and was markedly decreased, compared with the initial titer. Pyridostigmine and prednisolone dosages were tapered over the following 4 months without any evidence of recurrence of clinical signs. Thirty months after initial examination, the ferret was clinically normal and not receiving any treatment. A follow-up anti-acetylcholine receptor antibody titer was similar to previously published values for healthy ferrets.

CLINICAL RELEVANCE

Findings indicated that clinical and serologic remission can be achieved in ferrets with myasthenia gravis. However, owner willingness to provide extensive supportive care was vital to the outcome for this patient, as was the owner's decision to not euthanize the ferret despite an initial lack of response to treatment.

Comparison of lateral surgical margins of up to two centimeters with margins of three centimeters for achieving tumor-free histologic margins following excision of grade I or II cutaneous mast cell tumors in dogs

OBJECTIVE

To determine whether conservative lateral surgical margins (equal to tumor diameter for tumors < 2 cm in diameter or 2 cm for larger tumors) were noninferior to wide (3-cm) lateral surgical margins for achieving tumor-free histologic margins following excision of grade I and II cutaneous mast cell tumors (MCTs) in dogs.

ANIMALS

83 grade I and II MCTs excised with a deep surgical fascial margin and requisite lateral surgical margins from 68 dogs from 2007 to 2017. Tumors representing scar revision or local recurrence were excluded.

PROCEDURES

A pathology department database was searched to identify qualifying MCTs, and medical records were cross-referenced to obtain data regarding patients and tumors. Outcome (complete vs incomplete excision as histologically determined) was compared between conservative- and wide-margin groups. A noninferiority margin of ≥ 0.9 was used for the risk ratio (probability of complete excision for the conservative- vs wide-margin group), implying that noninferiority would be established if the data indicated that the true risk of complete excision with the conservative-margin approach was at worst 90% of that for the wide-margin approach.

RESULTS

The proportion of excised MCTs with tumor-free histologic margins was similar between the conservative- (43/46 [93%]) and wide- (34/37 [92%]) margin groups. There were no differences in tumor diameter or location between treatment groups. The risk ratio (1.02; 95% confidence interval, 0.89 to 1.19) met the criterion for noninferiority.

CONCLUSIONS AND CLINICAL RELEVANCE

The conservative-margin approach appeared to be noninferior to the wide-margin approach for achieving tumor-free histologic margins in the dogs of this study, and its use could potentially reduce the risk of postoperative complications. (J Am Vet Med Assoc 2020;256:567-572.

Apocrine gland anal sac adenocarcinoma in cats: 30 cases (1994-2015)

OBJECTIVE To describe the signalment, clinical signs, biological behavior, and outcome for cats with apocrine gland anal sac adenocarcinoma (AGASACA) that underwent surgical excision. DESIGN Retrospective case series. ANIMALS 30 client-owned cats. PROCEDURES Databases of 13 Veterinary Society of Surgical Oncology member-affiliated institutions were searched for records of cats with a histologic diagnosis of AGASACA that underwent tumor excision. For each cat, information regarding signalment, clinical signs, diagnostic test results, treatment, and outcome was extracted from the medical record. The Kaplan-Meier method was used to determine median time to local recurrence (TLR), disease-free interval (DFI), and survival time. Cox regression was used to identify factors associated with TLR, DFI, and survival time. RESULTS Perineal ulceration or discharge was the most common clinical sign in affected cats. Eleven cats developed local recurrence at a median of 96 days after AGASACA excision. Incomplete tumor margins and a high nuclear pleomorphic score were risk factors for local recurrence. Nuclear pleomorphic score was negatively associated with DFI. Local recurrence and a high nuclear pleomorphic score were risk factors for death. Median DFI and survival time were 234 and 260 days, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, in cats, perineal ulceration or discharge should raise suspicion of AGASACA and prompt rectal and anal sac examinations. Local recurrence was the most common life-limiting event in cats that underwent surgery for treatment of AGASACA, suggesting that wide margins should be obtained whenever possible during AGASACA excision. Efficacy of chemotherapy and radiation therapy for treatment of cats with AGASACA requires further investigation. (J Am Vet Med Assoc 2019;254:716-722).

Outcomes for dogs with functional thyroid tumors treated by surgical excision alone

OBJECTIVE

To describe clinical findings and survival times for dogs with functional thyroid tumors treated with surgery alone and investigate potential prognostic factors for outcome in these patients.

ANIMALS

27 client-owned dogs.

PROCEDURES

Medical records of 9 institutions were reviewed to identify dogs with hyperthyroidism secondary to thyroid neoplasia that were treated with surgery alone between 2005 and 2015. Data collected included signalment, hematologic and physical examination findings, tumor staging results, time from diagnosis to treatment, surgical procedure performed, histologic findings, evidence of recurrence or metastatic disease, and date of death or last follow-up. Median survival time and 1-, 2-, and 3-year survival rates were assessed by Kaplan-Meier analysis. Associations between variables of interest and the outcome of death were assessed with Cox proportional hazards models.

RESULTS

Dogs from 8 institutions met inclusion criteria. Median age at diagnosis was 10 years (range, 8 to 13 years). Golden Retrievers and Labrador Retrievers were commonly represented (5 dogs each). Polyuria with polydipsia (15/27 [56%]) and weight loss (12 [44%]) were the most common clinical signs; 2 dogs without clinical signs had hyperthyroidism identified by routine hematologic analysis. One dog had metastatic disease at the time of diagnosis. Most tumors (23/27 [85%]) were malignant. Estimated median survival time was 1,072 days. No significant prognostic factors were identified.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with resectable functional thyroid tumors had a good prognosis with surgical excision alone. Survival times for these dogs were similar to those in previous studies that included dogs with nonfunctional thyroid tumors.

Outcomes following balloon dilation for management of urethral obstruction secondary to urothelial carcinoma in dogs: 12 cases (2010-2015)

OBJECTIVE

To describe outcomes for dogs that underwent balloon dilation for palliative treatment of urethral obstruction caused by urothelial carcinoma.

ANIMALS

12 client-owned dogs.

PROCEDURES

Medical records were searched to identify dogs with urothelial (bladder, urethra, or prostate) carcinoma that underwent balloon dilation for treatment of urethral obstruction between April 2010 and December 2015. Information regarding history, signalment, clinical signs, diagnostic imaging findings, balloon dilation technique, clinical outcomes, complications, and additional treatments was obtained by review of medical records.

RESULTS

Improvement in clinical signs of urethral obstruction was observed after the initial dilation procedure for 9 of 12 dogs. Urethral obstruction was known to recur in 5 dogs 48 to 296 days after the initial procedure. Three of these dogs underwent a second dilation procedure, with clinical improvement in all 3 dogs for 41 to 70 days. One of 2 dogs that had a third procedure after the second reobstruction had clinical improvement in urinary tract signs until subsequent death from metastatic disease 22 days later. Complications included hematuria, urinary incontinence, and dysuria; these resolved within a few days after treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Urethral balloon dilation was a minimally invasive procedure that provided relief of urethral obstruction from urothelial carcinoma in most dogs of the study population. Prospective studies are needed to identify optimal techniques for balloon dilation in dogs with neoplastic urethral obstructions and to identify patients that are likely to benefit most from the treatment.

Partial vertical ear canal resection in two cats

CASE DESCRIPTION

An 18-year-old domestic medium-hair cat (cat 1) and a 16-year-old domestic shorthair cat (cat 2) were evaluated because of obstructive skin lesions involving the perimeter of the left external auditory canal.

CLINICAL FINDINGS

Otitis externa was present in affected ears secondary to obstructive soft tissue growths involving the outer margin of the external auditory canal and outer third of the vertical ear canal. Histologic examination of a preoperative biopsy sample revealed multiple ulcerated ceruminous gland adenomas in the affected ear of cat 1. Histologic examination of the submitted tissue from cat 2 confirmed ceruminous cystomatosis with surface colonization of yeast compatible with Malassezia spp.

TREATMENT AND OUTCOME

Both cats underwent partial resection of the upper third of the affected vertical ear canal and associated diseased skin. The incised margin of the pinna was sutured to the margin of the remaining portion of the vertical ear canal with absorbable sutures. Both cats were disease free over a 12-month (cat 1) or 10-month (cat 2) follow-up period. Cat 1 later developed a small ceruminous gland adenocarcinoma in the adjacent rostrolateral margin of the vertical ear canal 1 year after surgery; the mass was resected, and the patient was free of recurrence 4 months later.

CLINICAL RELEVANCE

Partial resection was an effective alternative to complete vertical ear canal resection for lesions involving the upper third of the vertical ear canal in these cats; the partial resection procedure was deemed simpler to perform and less traumatic to the cat. Functional and cosmetic results were excellent, with preservation of the overall anatomy of the external auditory canal.

Incidence of postoperative complications and outcome of 48 dogs undergoing surgical management of insulinoma

BACKGROUND

Information regarding outcome of dogs undergoing surgical management for insulinoma is based on studies of a small number of dogs.

OBJECTIVES

To report the outcomes of dogs undergoing surgery as treatment for insulinoma, the prevalence of postoperative diabetes mellitus (DM) in this group and to determine if development of DM can be predicted.

ANIMALS

Forty-eight client-owned dogs, with a histopathological diagnosis of insulinoma, from three European referral hospitals.

METHODS

Retrospective observational study. Dogs were identified from a search of electronic hospital records. Cox's regression was used to determine factors associated with postoperative survival and relapse, and logistic regression was used to determine factors associated with the development of DM.

RESULTS

Median survival time (MST) was 372 days (range 1-1680 days), with dogs with stage I disease having the longest survival time. Stage I dogs had MST of 652 days (range 2-1680 days), whereas dogs with either stage II or III disease had MST of 320 days (range 1-1260 days; P = 0.045). Postoperative hyperglycemia was identified in 33% (16/48) of the dogs, of which 9 (19% of the total population) developed persistent DM. No factors that could be used as predictors for development of DM were identified.

CONCLUSIONS AND CLINICAL IMPORTANCE

Stage of disease and postoperative hypoglycemia were associated with greater odds of relapse and decreased survival time; these could be used when discussing prognosis. In this study, postoperative DM developed more commonly than previously reported, but no factors were identified that might be useful predictors.

Cranial tibial fascia autograft for wound closure following hemipelvectomy in a cat

A 13-year-old cat underwent an extensive caudal external hemipelvectomy to excise a soft tissue sarcoma affecting the left proximal thigh. The cranial tibial fascia was harvested from the ipsilateral limb following amputation and used as a free graft in the reconstruction of the resultant pelvic and abdominal wall defect. Wound healing was uncomplicated, and 6 months following surgery there was no evidence of tumor recurrence or loss of integrity of the abdominal wall or lateral rectal support. Key clinical message: The cranial tibial fascia appears to be an effective autograft tissue for reconstructive surgery and may be applicable for closure of extensive hemipelvectomy procedures performed for tumors affecting the femoral region.

Identification of A Novel Papillomavirus Associated with Squamous Cell Carcinoma in A Domestic Cat

Papillomaviruses infect the skin and mucosal surfaces of diverse animal hosts with consequences ranging from asymptomatic colonization to highly malignant epithelial cancers. Increasing evidence suggests a role for papillomaviruses in the most common cutaneous malignancy of domestic cats, squamous cell carcinoma (SCC). Using total DNA sequencing we identified a novel feline papillomavirus in a nasal biopsy taken from a cat presenting with both nasal cavity lymphoma and recurrent squamous cell carcinoma affecting the nasal planum. We designate this novel virus as Felis catus papillomavirus 6 (FcaPV6). The complete FcaPV6 7453 bp genome was similar to those of other feline papillomaviruses and phylogenetic analysis revealed that it was most closely related to FcaPV3, although was distinct enough to represent a new viral type. Classification of FcaPV6 in a new genus alongside FcaPVs 3, 4 and 5 is supported. Archived excisional biopsy of the SCC, taken 20 months prior to presentation, was intensely positive on p16 immunostaining. FcaPV6, amplified using virus-specific, but not consensus, PCR, was the only papillomavirus detected in DNA extracted from the SCC. Conversely, renal lymphoma, sampled at necropsy two months after presentation, tested negative on FcaPV6-specific PCR. In sum, using metagenomics we demonstrate the presence of a novel feline papillomavirus in association with cutaneous squamous cell carcinoma.

A perineal cystic hamartoma causing constipation in an intact female Irish water spaniel

A perineal fluid-filled structure was discovered in a 6-year-old intact female Irish water spaniel suffering from intermittent constipation. Diagnostic tests revealed the structure was immediately caudal to the vagina and compatible with a cyst. Surgical excision was required for resolution of clinical signs. Histology confirmed the structure was a cyst. The exact origin is unknown; however, the variety of lining epithelia, including sections with mucin production, and a well-differentiated smooth muscle layer, were most consistent with development from the lower hindgut or urogenital sinus during embryonic growth. The histologic and anatomical similarities with human retrorectal cystic hamartomas were key in establishing the diagnosis of a perineal cystic hamartoma. Following removal, constipation resolved, and the cyst did not recur.

Common bile duct obstruction palliated with common bile duct re-implantation (choledochoduodenostomy) in a cat

A cat was presented with complete biliary obstruction at the level of the distal common bile duct (CBD), with loss of normal architecture. The area was excised and submitted for histopathology. Concurrent cholecystitis and gall bladder necrosis necessitated cholecystectomy. The proximal CBD was preserved and re-implanted adjacent to the original duodenal papilla. The cat recovered and remained asymptomatic for 6 months. At clinical relapse a carcinoma of suspected biliary origin was confirmed, and the cat was euthanized. In situations in which the CBD lumen cannot be re-established, the pathology is limited to the distal CBD, and the gall bladder is not available for cholecystoenterostomy, CBD re-implantation may be an option to salvage and retain a functional biliary tree.

Limb-shortening limb salvage (LSLS) in a cat with metatarsal osteosarcoma

The objective of this report was to document a successful partial limb amputation surgery in a cat with metatarsal osteosarcoma (OSA) including the use of pad grafts from the amputated foot. Limb shortening of the hindlimb through a partial amputation resulted in excellent limb function and usage. The patient retained functional use of the limb after surgery, with no lameness. There was no evidence of metastasis or local recurrence seen 323 days post-surgery. Limb shortening partial amputation is a reasonable option and can result in excellent limb use after surgery despite a significant loss in limb length.

Intraoperative acridine orange photodynamic therapy and cribriform electron-beam irradiation for canine intranasal carcinomas: 14 cases

Canine intranasal carcinomas are almost always malignant. Surgery alone often results in rapid tumor regrowth. Radiotherapy is the treatment of choice for dogs with intranasal tumors. Here, we retrospectively assessed treatment of intranasal carcinoma by marginal tumor resection followed by intraoperative acridine orange (AO) photodynamic therapy (PDT) and cribriform plate electron-beam intraoperative radiotherapy (IORT). Fourteen canine cases were assessed, 12 of which had stage I tumors, one with stage III, and one with stage IV. Recurrence was detected in 8, with a median recurrence from the time of treatment of 6 months (range: 3 to 16 months). The median progression-free survival time and overall survival time after treatment were 13 and 22 months, respectively. Adverse events were mild. Marginal tumor resection followed by intraoperative AO-PDT and cribriform plate electron-beam IORT may increase the tumor control time in dogs with marginally resectable intranasal malignant tumors beyond that incurred by surgery alone.

Outcome and clinical, pathological, and immunohistochemical factors associated with prognosis for dogs with early-stage anal sac adenocarcinoma treated with surgery alone: 34 cases (2002-2013)

OBJECTIVE To determine survival time and metastatic rate for dogs with early-stage anal sac adenocarcinoma (ASACA) treated with surgery alone and assess whether specific clinical, pathological, or immunohistochemical factors were predictive of outcome for those dogs. DESIGN Retrospective case series. ANIMALS 34 dogs with early-stage, nonmetastatic ASACA that were treated with surgery only. PROCEDURES Medical record databases of 2 referral hospitals were searched to identify dogs examined between 2002 and 2013 that had a diagnosis of nonmetastatic ASACA that was < 3.2 cm at its largest diameter. Only dogs that received surgical treatment alone were included in the study. For each dog, information extracted from the medical record included signalment, clinical and diagnostic test findings, tumor characteristics, and outcome. When available, archived tumor specimens were histologically reviewed and tumor characteristics were described; Ki-67 and E-cadherin expressions were evaluated by use of immunohistochemical methods. Clinical, pathological, and immunohistochemical factors were assessed for associations with survival time and tumor recurrence and metastasis rates. RESULTS Median survival time was 1,237 days. Seven dogs had tumor recurrence and 9 dogs developed metastatic disease at a median of 354 and 589 days, respectively, after primary tumor removal. Cellular pleomorphism was positively associated with development of metastatic disease. No other factors evaluated were associated with outcome. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated dogs with early-stage nonmetastatic ASACA generally had a favorable outcome following surgical removal of the primary tumor alone. Routine rectal examination may be a simple and useful method for detection of dogs with early-stage ASACA.

Basal Cell Adenoma of the Salivary Gland and Possible Recurrence as Basal Cell Adenocarcinoma in a Black-tailed Prairie Dog (Cynomys ludovicianus)

We describe a black-tailed prairie dog (Cynomys ludovicianus) with a benign biphasic nodular tumour that recurred as a malignant biphasic tumour at the same site 2 years after resection. Both tumours were biphasic with regard to the glandular epithelium and basal cells and contained little of the mucus, cartilage or fibrous tissue that characterize pleomorphic adenoma and carcinoma ex-pleomorphic adenoma. Both the first and second tumours exhibited histopathological features similar to those exhibited by human basal cell adenoma and adenocarcinoma, respectively. Both were resected and the animal was alive with no recurrence or metastasis at the time of writing, 9 months after the second surgery.

Retrobulbar malignant peripheral nerve sheath tumor in a golden retriever dog: A challenging diagnosis

A 9-year-old golden retriever dog was diagnosed with a left retrobulbar mass. Fine-needle aspirations and incisional biopsies resulted in discordant diagnoses: myxosarcoma/myxoma or rhadomyosarcoma, respectively. Immunohistochemistry following exenteration allowed definitive diagnosis of malignant peripheral nerve sheath tumor with fibromyxomatous differentiation. Fifteen weeks after surgery, an aggressive recurrence resulted in euthanasia.