Fragmented palmar metacarpophalangeal sesamoids in dogs: a long-term evaluation

Long-term clinical and radiographicresponse to surgical and conservativemanagement of 22 dogs with fragmentedsesamoids was evaluated. Mean follow-up was 3.6 years (range = 3 monthsto 11.0 years).

Initial (retrospective) and follow-up(prospective) radiographs of the affectedpalmar sesamoids and associatedmetacarpophalangeal joints were evaluatedusing a graded scoring system. A lameness evaluation and physicalexamination were performed at followupin a blinded manner. In addition,owners were asked to complete a questionnaireregarding their pet’s thoraciclimb lameness.

There was not any difference betweengroups (sesamoidectomy, conservativemanagement, incidental finding)in age at onset, duration of lamenessprior to therapy, body weight at treatment, time to follow-up, number ofaffected joints, nor owner perceptionsof whether they thought the lamenessimproved, resolved, or recurred, andwhether or not they were pleased withthe outcome.

Sesamoid fragmentation treated bysesamoidectomy resulted in significantlygreater progression of radiographicchanges that were consistentwith degenerative joint disease.

Chronic lameness resolved or improvedto the point of owner satisfactionwith conservative therapy in most cases. Continued lameness, or recurrent,although improved lameness associatedwith heavy activity, occurred followingsurgical extirpation of the affectedsesamoids in many cases. Given thesefindings, a more conservative approachto the treatment of chronic lamenessassociated with sesamoid fragmentationmay be warranted.

Long-term clinical and radiographic response to surgical and conservative management of 22 dogs with fragmented sesamoids was evaluated. Mean follow-up was 3.6 years. Sesamoid fragmentation treated by sesamoidectomy resulted in significantly greater progression of radiographic changes that were consistent with degenerative joint disease. Chronic lameness resolved or improved to the point of owner satisfaction with conservative therapy in most cases. Continued or recurrent lameness was common following sesamoidectomy. Conservative therapy should be attempted prior to sesamoidectomy for dogs with chronic lameness associated with palmar metacarpophalangeal sesamoid fragmentation.

Ratite cancellous xenograft: effects on avian fracture healing

A segmental radial defect model was used to radiographically and histologically evaluate response to ratite cancellous xenograft in pigeons. The control group showed little evidence of callus production with all fractures proceeding to nonunion. Lymphocytic response to xenograft peaked at four weeks and diminished thereafter. Fractures treated with cancellous xenograft had significant increases in new bone production.

Avian Fracture Healing Following Stabilization with Intramedullary Polyglycolic Acid Rods and Cyanoacrylate Adhesive vs. Polypropylene Rods and Polymethylmethacrylate

Avian fracture healing was evaluated for twelve weeks following the repair of transverse mid-diaphyseal humeral fractures. Radiographic, histological, and biomechanical assessment of healing was used to compare a currently used method of repair - a permanent intramedullary polypropylene rod and polymethylmethacrylate bone cement, to a new biodegradable repair technique which utilized intramedullary polyglycolic acid rods and cyanoacry-late adhesive. Histological response to the biodegradable implants consisted of a granulomatous foreign body reaction that did not impair fracture healing. Fibrous encapsulation occurred around the permanent devices. Biodegradable repairs developed more periosteal callus, and early complications were more common following biodegradable repair, but there was little difference between the two groups biomechanically. Polyglycolic acid implants appear to be viable alternatives for the repair of some avian fractures. Investigation into the use of other biodegradable polymers for avian fracture fixation is warranted.

Avian fracture healing following the repair of trans-verse humeral fractures with intramedullary biodegradable polyglycolic acid (PGA) rods and cyanoacrylate adhesive was compared to healing following repair with polypropylene rods and polymethylmethacrylate (PMMA) bone cement. Foreign body reaction to the PGA/cyanoacrylate fixation occurred, but did not impair fracture healing. Biomechanical testing revealed few differences between the two fixation methods at 0-12 weeks following fracture repair.

Association of Gallbladder Mucocele Histologic Diagnosis with Selected Drug Use in Dogs: A Matched Case-Control Study

Background

The cause of gallbladder mucocele (GBM) formation in dogs currently is unknown. Many available drugs represent a newer generation of xenobiotics that may predispose dogs to GBM formation.

Objective

To determine if there is an association between the histologic diagnosis of GBM in dogs and administration of selected drugs.

Animals

Eighty‐one dogs with a histologic diagnosis of GBM and 162 breed, age, and admission date‐matched control dogs from a single referral institution.

Methods

Medical records of dogs with GBM and control dogs from 2001 to 2011 were reviewed. Owner verification of drug history was sought by a standard questionnaire. Reported use of heartworm, flea, and tick preventatives as well as nonsteroidal anti‐inflammatory drugs, analgesics, corticosteroids, or medications for treatment of osteoarthritis was recorded.

Results

Dogs with GBM were 2.2 times as likely to have had reported use of thyroxine (as a proxy for the diagnosis of hypothyroidism) as control dogs (95% confidence interval [CI], 0.949–5.051), 3.6 times as likely to have had reported treatment for Cushing's disease (95% CI, 1.228–10.612), and 2.3 times as likely to have had reported use of products containing imidacloprid (95% CI, 1.094–4.723). Analysis of a data subset containing only Shetland sheepdogs (23 GBM and 46 control) indicated that Shetland sheepdogs with GBM formation were 9.3 times as likely to have had reported use of imidacloprid as were control Shetland sheepdogs (95% CI, 1.103–78.239).

Conclusions and Clinical Importance

This study provides evidence for an association between selected drug use and GBM formation in dogs. A larger epidemiologic study of Shetland sheepdogs with GBM formation and exposure to imidacloprid is warranted.

Canine pubic symphysiodesis: investigation of electrocautery dose response by histologic examination and temperature measurement

OBJECTIVES

To determine thermal necrosis zone and the maximal temperature achieved with various electrocautery doses applied to the pubic symphysis of immature dogs, and to establish the minimal electrocautery dose needed to affect thermal necrosis of the germinal chondrocytes of the immature canine pubis.

STUDY DESIGN

A randomized, controlled, prospective study.

ANIMALS

Twelve puppies, 15 to 17 weeks of age.

METHODS

Each treated puppy was randomly selected to receive 3 of 33 possible doses of electrical current applied at uniform intervals along the pelvic symphysis. Three treatment sites were sham-operated controls. All treatment zones were biopsied 7 days after application of electrocautery. Confocal laser microscopy with calcein green and ethidium homodimer red stains were used to determine cell type and viability within treatment and control zones. The physeal diameter and thermal necrosis zone were measured. Thermal necrosis zone and dose, and temperature and dose were compared using regression analysis. Prediction equation analysis was used to establish dose recommendations.

RESULTS

Doses of 40 W produced a highly significant linear relationship (R(2) =.88, P <.01) with thermal necrosis zone, and a significant linear relationship (R(2) =.76, P <.02) with maximal temperature.

CONCLUSIONS

The thermal necrosis zone within the pelvic symphysis and maximal temperature achieved can be reliably predicted using electrocautery doses of 40 W. For application of electrocautery to induce pubic symphysiodesis, doses should be chosen based on measured or estimated physeal size. Using prediction equation analysis, the surgeon can plan mean thermal necrosis zone with acceptable variance.

CLINICAL RELEVANCE

Unipolar needle electrocautery can be used to reliably achieve symphyseal necrosis. Prediction equation analysis can be used to determine 40-W doses.

Effects of pubic symphysiodesis in dysplastic puppies

OBJECTIVE

To determine the long-term effects of juvenile pubic symphysiodesis (JPS) in dysplastic puppies.

STUDY DESIGN

Prospective, randomized, clinical trial.

ANIMALS

Seven dysplastic Chesapeake Bay retrievers and 2 beagle-crosses (BX1 and 2).

METHODS

Five puppies had JPS performed with electrocauterization at 12, 16, 20, 22, and 24 weeks of age, respectively. Two puppies served as controls. BX1 and BX2 were used to obtain biopsies of the symphysis. Hips were evaluated for: pelvic development (transverse computerized tomography for acetabular angle [AA] and dorsal acetabular rim angle [DARA]); laxity [hip extended and stress radiography [distraction index (DI)]); Ortolani maneuver with reduction angles; acetabular coverage (Norberg angles); and function (coxofemoral range of motion, hip pain, and gait analysis by force-plate technique at 44 and 137 weeks of age).

RESULTS

The pubis fused prematurely in every puppy that was operated on with the JPS technique. Greater acetabular responses were related to younger ages at surgery. The final mean AA in dogs that had JPS was 25 degrees greater than preoperative values; 40% increased over control. The DARA final mean was 10 degrees, 52% less than preoperative values and 46% less than control. The final mean DI in dogs having JPS was 0.28, 47% improved over preoperative values and 58% better than control. Mean pelvic dimensions in dogs that had JPS were 18% less than control. Gait analyses were normal for all dogs at 137 weeks. No urinary or bowel complications occurred.

CONCLUSIONS

Significant ventrolateral acetabular rotation, increased hip coverage, diminished hip laxity, normal pain-free gait, and insignificantly reduced pelvic size occurred after JPS.

CLINICAL SIGNIFICANCE

Dysplastic hips in young dogs were significantly improved by JPS.

Surgery of the canine vagina and vulva

Accurate diagnosis of canine vaginal abnormalities often requires general anesthesia, vaginoscopy, and contrast radiography. Abdominal ultrasonography, thoracic radiography, computed tomography, and histopathology may also be advised for the workup of mass lesions before surgery. Many procedures such as episioplasty and resection of pedunculated vaginal masses or edematous tissue are easily performed with proper planning and equipment (e.g., electrocautery). Consideration should be given to referring more complicated procedures such as resection of large vaginal masses or vaginal stenoses to a board-certified surgeon. Finally, preoperative placement of a fentanyl patch and pre- or postoperative epidural analgesia are highly recommended for any vulvovaginal surgical procedure.

Management of hypertension controls postoperative neurologic disorders after renal transplantation in cats

OBJECTIVES

To determine the prevalence and describe the management of hypertension and central nervous system (CNS) complications after renal transplantation in cats. We also compared the prevalence of CNS complications between cats monitored and treated for postoperative hypertension and a previously described, historical control group of cats not monitored or treated for postoperative hypertension.

STUDY DESIGN

Retrospective clinical study.

ANIMALS OR SAMPLE POPULATION

A total of 34 client-owned cats that received renal allografts for the treatment of end-stage renal failure.

METHODS

Medical records were reviewed. Data obtained included preoperative and postoperative systolic blood pressures, antihypertensive therapy, response to treatment, neurologic signs, and clinical outcome. The results were compared with a historical control group of feline renal allograft recipients that were neither monitored nor treated for postoperative hypertension.

RESULTS

Severe postoperative hypertension occurred in 21 of 34 of cats. Hypertension was treated in all 21 cats with subcutaneously administered hydralazine which reduced systolic blood pressure to less than 170 mm Hg in 15 minutes in 20 of 21 cats; hydralazine produced hypotension in one cat and failed to control hypertension in 1 cat. After transplantation, seizures were observed in one cat and other neurologic complications (stupor, ataxia, and central blindness) were observed in three cats. The prevalence of seizures and neurologic complication-related deaths after transplantation was significantly reduced with treatment of postoperative hypertension.

CONCLUSIONS AND CLINICAL RELEVANCE

Hypertension is a major contributing factor to postoperative seizure activity after renal transplantation in cats; treatment of hypertension reduces the frequency of neurologic complications.

Comparison of topical administration of clotrimazole through surgically placed versus nonsurgically placed catheters for treatment of nasal aspergillosis in dogs: 60 cases (1990-1996)

OBJECTIVE

To examine the clinical response to topical administration of clotrimazole in dogs with nasal aspergillosis, to compare effect of surgically placed versus nonsurgically placed catheters used for administration on outcome, and to examine whether subjective scoring of computed tomographic images can predict outcome.

DESIGN

Retrospective case series.

ANIMALS

60 dogs with nasal aspergillosis.

PROCEDURE

Information including signalment, history, diagnostics, treatment method, and outcome was retrieved from medical records of dogs with nasal aspergillosis treated between 1990 and 1996 at the University of California School of Veterinary Medicine or cooperating referral practices. Final outcome was determined by telephone conversations with owners and referring veterinarians. Images obtained before treatment were subjectively assessed to develop an algorithm for predicting outcome.

RESULTS

Clotrimazole solution (1%) was infused during a 1-hour period via catheters surgically placed in the frontal sinus and nose (27 dogs) and via nonsurgically placed catheters in the nose (18). An additional 15 dogs received 2 to 4 infusions by either route. Topical administration of clotrimazole resulted in resolution of clinical disease in 65% of dogs after 1 treatment and 87% of dogs after one or more treatments. The scoring system correctly classified dogs with unfavorable and favorable responses 71 to 78% and 79 to 93% of the time, respectively.

CLINICAL IMPLICATIONS

Topical administration of clotrimazole, using either technique, was an effective treatment for nasal aspergillosis in dogs. Use of non-invasive intranasal infusion of clotrimazole eliminated the need for surgical trephination of frontal sinuses in many dogs and was associated with fewer complications.

Renal transplants in cats: 66 cases (1987-1996)

OBJECTIVE

To document the morbidity and survival time after renal transplants in cats with end-stage renal failure.

DESIGN

Retrospective case series.

ANIMALS

66 cats that had renal transplants.

PROCEDURE

Information regarding signalment, history, diagnostic testing, and postoperative morbidity and mortality was retrieved from medical records of cats with renal failure that had renal transplants at the University of California School of Veterinary Medicine between 1987 and 1996.

RESULTS

47 of 66 (71%) cats that had renal transplants survived until discharge. Nineteen cats died in the perioperative period. Most common causes of death were seizure-related complications (7 cats) and renal pedicle complications (4). One discharged cat was unavailable for follow-up monitoring. Of the 46 cats discharged and available for follow-up monitoring, 28 died. Most common causes of death in these cats were renal complications (9 cats) and death related to immunosuppression (8; mean and median survival times, 15 and 12 months, respectively). Of the 18 cats that were still living at the time this report was written, mean and median survival times were 26 and 22 months, respectively.

CLINICAL IMPLICATIONS

Renal transplantation resulted in long-term survival of many cats that would have otherwise died from, or have been euthanatized as a result of, renal failure. Problems with ureteral obstruction can be minimized. Postoperative CNS disorders were the most prevalent complication.

Central nervous system disorders after renal transplantation in cats

OBJECTIVE

This study describes the incidence and severity of postoperative central nervous system (pCNS) disorders in feline renal transplant recipients.

STUDY DESIGN

A retrospective study based on the medical records of cats that received renal allografts from 1987 to 1996.

ANIMALS OR SAMPLE POPULATION

Fifty-seven client-owned cats received renal allografts for the treatment of renal failure.

METHODS

The frequency, duration, severity, and treatment of episodes of pCNS disorders were recorded from the medical records.

RESULTS

Twelve (21%) of 57 cats had pCNS disorders 1 hour to 5 days after the surgical procedure. Seven cats survived; four had single or multiple seizure episodes, and two had seizure episodes or disorientation followed by a period of coma. One cat became temporarily ataxic and blind after restraint for venipuncture. Five cats died; all had episodes of disorientation or seizures, or both, that progressed to a nonrecoverable comatose state, respiratory arrest or cardiac arrest, or both. There were no significant differences between the two groups in preoperative serum creatinine, blood urea nitrogen, or cholesterol levels, and intraoperative blood pressure measurements. There were no significant differences in the postoperative serum glucose levels, electrolytes levels, or osmolality between the two groups. The cats with pCNS disorders had a mean preoperative trough cyclosporine A (CyA) whole blood level of 429 ng/mL; cats without pCNS disorders had a significantly (P = .0116) higher mean preoperative trough CyA whole blood level of 736 ng/mL.

CONCLUSION

Central nervous system disorders are a common and often fatal complication of renal transplantation in cats.

CLINICAL RELEVANCE

Recognition of pCNS disorders, and possible causes, will help develop hypotheses to investigate the problem.

Basal cell carcinoma in a blue-fronted amazon parrot (Amazona aestiva)

Tumors of the integumentary system are relatively common in companion birds. Dermal tumors in pet birds can be epithelial, mesenchymal, or vascular in origin. Basal cell carcinomas appear to be extremely rare in birds. An adult female blue-fronted Amazon parrot was examined because it exhibited bilateral cervical masses that extended from the base of the skull to the ingluvial region. The tumors were removed by surgical excision. Microscopic examination of the masses revealed neoplastic epithelial cells that extended to all borders of the sections; scattered vessels with neoplastic cells within their lumens were also found. The histopathologic diagnosis was basal cell carcinoma. Six weeks postoperatively, the masses recurred and the bird was euthanatized. This report suggests that basal cell carcinomas should be considered as a differential for avian dermal tumors. This neoplastic condition can be aggressive and has the potential to metastasize.

Pulmonary lobectomy in the management of pneumonia in five cats

Five cats underwent lobectomy for the management of pneumonia. The mean presurgical duration of treatment was eight months. A potentially immunosuppressive disease process was present preoperatively in two of the five cats. Preoperatively, two of the cats had radiographically diffuse pneumonia, while three had focal pneumonia. A single pulmonary lobe was removed in four cats, with one cat having two pulmonary lobes removed. There were no life-threatening complications and no clinical recurrence noted during a mean follow-up period of 37.8 months. The benefit of pulmonary lobectomy in focal pneumonia may lie in removing the nidus of infection. In diffuse, chronic or medically refractory pneumonia, obtaining an aetiological diagnosis may be the main benefit of lobectomy. Selective lobectomy for the treatment of pneumonia may be beneficial but a thorough preoperative evaluation is warranted.

Pulmonary lobectomy in the management of pneumonia in dogs: 59 cases (1972-1994)

OBJECTIVE

To evaluate the risk and efficacy of pulmonary lobectomy in dogs with pneumonia.

DESIGN

Retrospective study.

ANIMALS

59 dogs with pneumonia.

PROCEDURE

Review of medical records and telephone conversations.

RESULTS

54.2% of dogs had resolution of pneumonia after lobectomy, 20.3% died in the perioperative period, and 25.4% survived the perioperative period but pneumonia did not resolve. Pneumonia was caused by bacteria (25 dogs), fungi (12), foreign bodies (8), parasites (1), viruses (1), and allergies (1). In 11 dogs, the etiologic agent was not isolated. Bacterial or fungal pneumonias were significantly less likely to resolve compared with foreign body pneumonia or when an etiologic agent was not isolated. Perioperative mortality rate increased significantly with an increase in number of pulmonary lobes removed. Complications during surgery significantly increased perioperative mortality rate. Surgical era (1972 to 1983 vs 1984 to 1994) was a significant predictor of mortality, with the odds of dying in the perioperative period being 11 times greater between 1972 to 1983. The odds of failure to resolve pneumonia was 3 times greater during 1972 to 1983.

CLINICAL IMPLICATIONS

Number of pulmonary lobes removed and complications during surgery significantly affect perioperative mortality rate. Identification of etiologic agents may help in predicting dogs likely to resolve pneumonia after surgery.

Effect of pubic symphysiodesis on acetabular rotation and pelvic development in guinea pigs

OBJECTIVE

To evaluate the effect of premature closure of the pubic symphysis on pelvic development.

ANIMALS

18, 21-day-old male guinea pigs.

PROCEDURE

The pubic symphysis was surgically approached in 10 guinea pigs of the symphysiodesis group and in 4 of the sham-operated group; 4 guinea pigs served as unoperated controls. The pubic symphysis was destroyed by use of electrocautery in the 10 guinea pigs of the symphysiodesis group. All guinea pigs were allowed to grow to skeletal maturity and were euthanatized at 33 weeks of age. Body weight was recorded throughout the study and was compared between groups. Histologic examination of the symphyses confirmed premature closure of the pubic symphyseal growth plates in guinea pigs of the symphysiodesis group. Pelvic measurements taken from pretreatment radiographic views and from video images of harvested pelves were compared between groups.

RESULTS

There were no significant differences between groups with regard to pretreatment radiographic variables, rate of weight gain, or body weight at any time. Pubic symphysiodesis resulted in significant narrowing of the caudal aspect of the pelvis, narrowing and shortening of the pubic bones, and outward rotation of the acetabula.

CONCLUSIONS

The pubic symphyseal growth plates contribute significantly to development of the pelvis. Premature closure of these growth plates (pubic symphysiodesis) results in outward rotation of the acetabula, which might be beneficial in some cases of can be hip dysplasia; however, this rotation is accompanied by concomitant narrowing of the caudal aspect of the pelvis.

Computed tomographic assessment of noninvasive intranasal infusions in dogs with fungal rhinitis

The distribution of infusate administered to 12 dogs with fungal rhinitis, using a noninvasive, intranasal technique, was evaluated by computed tomography (CT). In every dog, contrast medium was identified on the postinfusion CT images, within the frontal sinuses, and throughout all areas of the nasal cavity. Adverse effects were transient and mild. The results of this study indicate that intranasal infusion may be a viable alternative to trephination of the frontal sinuses to administer antifungal medications in dogs with fungal rhinitis.

Distribution of topical agents in the frontal sinuses and nasal cavity of dogs: comparison between current protocols for treatment of nasal aspergillosis and a new noninvasive technique

To document and compare patterns of distribution of topically applied antifungal medication, heads from 42 canine cadavers were assigned to seven treatment groups which included two current surgical treatment protocols for nasal aspergillosis, and a new, noninvasive method. Catheters (8 Fr) were placed through trephine holes into the frontal sinuses and nasal cavity. Dilute dye was injected through the catheters and the heads were sectioned sagittally. The administration of 5 mL of dye into the lateral frontal sinus and nasal cavity (group IA, 10 mL total) was compared with 25 mL injected through catheters placed bilaterally in the lateral frontal sinus and nasal cavity (group II, 100 mL total). Both were compared with the administration of 50 mL of dye through a catheter placed in the dorsal nasal meatus via each nostril (group III). The heads in group III had significantly (P < .05) better dye distribution to all cavities than group IA and better distribution to the rostral frontal sinus than group II. Groups IV to VI were designed to show the pattern of distribution of dye to the contralateral nasal cavity and frontal sinuses. In all groups, dye injected into the lateral frontal sinus did not cross into the ipsilateral rostral frontal sinus or vice versa unless the transverse septum dividing the compartments had been penetrated during trephination.

Resolution of lameness associated with Scottish fold osteodystrophy following bilateral ostectomies and pantarsal arthrodeses: a case report

Bilateral hind-limb lameness, associated with tarsal exostoses in a Scottish fold diagnosed as having Scottish fold osteodystrophy, resolved following staged bilateral ostectomies and pantarsal arthrodeses. Degenerative changes in the phalangeal joints of the hind limbs have progressed radiographically, but lameness has not recurred 48 weeks following the second arthrodesis. Additional skeletal abnormalities were detected radiographically in both carpi and in several caudal vertebrae. A partial, left-sided conduction deafness was diagnosed by evaluating brain stem auditory-evoked responses.