Treatment of pancreatitis-associated extrahepatic biliary tract obstruction by choledochal stenting in seven cats

OBJECTIVES: To report the clinicopathological findings and outcome in cats with pancreatitis-associated extrahepatic biliary tract obstruction (EHBO) treated by choledochal tube stenting. METHODS: Medical records of cats with EHBO secondary to pancreatitis that underwent choledochal stenting were reviewed. Information on outcome was obtained by re-examination of the cat or by telephone interview with the owners. RESULTS: All cats had pancreatitis confirmed by histopathological examination of biopsy samples (n=6) or suspected based on gross examination at surgery (n=1). In six cats, a section of 3.5 to five French gauge red rubber catheter and in one cat a section of 22 G intravenous catheter were used as a choledochal stent. Two cats developed re-obstruction of the biliary tract within a week of the original surgery. One cat had confirmed episodes of ascending cholangitis postoperatively. Two cats had chronic intermittent vomiting in the postoperative period. Two cats died during the perioperative period. Five cats survived to discharge, three of which died seven to 24 months postoperatively and two of which remain alive to date. CLINICAL SIGNIFICANCE: Choledochal stenting is an alternative to biliary diversion for management of feline pancreatitis-associated EHBO in select cases. However, there may be greater morbidity with this technique in cats compared with dogs.     

Pathogenesis and outcome of extrahepatic biliary obstruction in cats

Extrahepatic biliary obstruction (EHBO) was confirmed at surgery or necropsy in 22 cats. Biliary or pancreatic adenocarcinoma was diagnosed by histopathology in six cats and one cat had an undiagnosed mass in the common bile duct. The remaining 15 cats had at least one of a complex of inflammatory diseases including pancreatitis, cholangiohepatitis, cholelithiasis and cholecystitis. The most common clinical signs were jaundice, anorexia, lethargy, weight loss and vomiting. Hyperbilirubinaemia was present in all cases. Distension of the common bile duct and gall bladder was the most commonly observed finding on abdominal ultrasound. Nineteen cats underwent exploratory laparotomy for biliary decompression and diversion. Mortality in cats with underlying neoplasia was 100 per cent and, in those with non-neoplastic lesions, was 40 per cent. Long-term complications, in those that survived, included recurrence of cholangiohepatitis, chronic weight loss and recurrence of obstruction. Based on these findings, the prognosis for EHBO in cats must be considered guarded.     

Use of hepatobiliary scintigraphy in the diagnosis of extrahepatic biliary obstruction in dogs and cats: 25 cases (1982-1989).

Twenty-five animals (21 dogs and 4 cats) in which hepatobiliary scintigraphy (HBS) was performed between 1982 and 1989 were included in a retrospective study to determine the utility of HBS for diagnosis of extrahepatic biliary obstruction. Final diagnoses, which were based on liver biopsy results and surgical findings in all animals, were hepatocellular disease alone (n = 17), hepatocellular disease and extrahepatic biliary obstruction (n = 7), and normal liver (n = 1). Hepatobiliary scintigraphy was performed by use of 99mTc-diisopropyl iminodiacetic acid in all cases. All 7 cases of extrahepatic biliary obstruction were confirmed at surgery. In animals with biliary obstruction, HBS failed to demonstrate radiolabel within either the gallbladder or intestine at any time. Using nonvisualization of the intestine by 180 minutes as the scintigraphic criterion for diagnosis of biliary obstruction, sensitivity was 83% and specificity was 94% in this series. Hepatobiliary scintigraphy was concluded to be an accurate indicator of extrahepatic biliary obstruction in this group of animals. High serum bilirubin concentration at the time HBS was performed did not appear to reduce the diagnostic usefulness of the scintigraphic findings.     

Osteosarcoma in cats: 22 cases (1974-1984)

Osteosarcoma was diagnosed in 22 cats. Diagnosis was based on results of physical, radiographic, and histologic findings. Fifteen tumors arose from the appendicular skeleton, 4 from the skull, 2 from the pelvis, and 1 from a rib. Radiography revealed that in 14 of 15 cats (93%) with appendicular tumors, the lesion was metaphyseal, primarily lytic, with a "moth-eaten" appearance; absence and presence of periosteal new bone formation were associated with the tumors in 12 and 3 cats, respectively. The remaining 7 cats had axial tumors that were characterized by the presence of periosteal new bone formation in addition to bony lysis. Of the 15 cats with appendicular tumors, 12 were treated by amputation and 3 were euthanatized at the time of diagnosis. Of the cats undergoing amputation for treatment of their appendicular tumors, 6 cats were still alive 64 months after surgery (range, 13 to 64 months); the median survival time of the 5 cats (1 cat was lost to follow-up evaluation) that died was 49.2 months (range, 1 to 122 months). Four of 12 cats (33%) survived greater than or equal to 5 years after diagnosis. Of the cats with axial tumors that were not euthanatized at the time of diagnosis (6 of 7), the median survival time was 5.5 months. Based on these findings, we concluded that cats with appendicular osteosarcoma have a better prognosis than those with axial osteosarcoma, and that amputation is a viable treatment for cats with appendicular osteosarcoma.     

Corynebacterium urealyticum urinary tract infection in dogs and cats: 7 cases (1996-2003)

OBJECTIVE: To identify clinical features of Corynebacterium urealyticum urinary tract infection in dogs and cats and antimicrobial susceptibility patterns of C urealyticum isolates. DESIGN: Retrospective study. ANIMALS: 5 dogs and 2 cats. PROCEDURE: Medical records of dogs and cats for which C urealyticum was isolated from urine samples were reviewed. Isolates from clinical cases, along with previously lyophilized unsubtyped isolates of Corynebacterium spp collected between 1977 and 1995, were examined and, if subtyped as C urealyticum, tested for antimicrobial susceptibility. RESULTS: Signalment of infected animals was variable. Prior micturition disorders were common, and all animals had signs of lower urinary tract disease at the time C urealyticum infection was diagnosed. Median urine pH was 8.0; WBCs and bacteria were variably seen in urine sediment. In vitro antimicrobial susceptibility testing of 14 C urealyticum isolates revealed that all were susceptible or had intermediate susceptibility to chloramphenicol, tetracycline, and vancomycin and most were susceptible to enrofloxacin. Thickening of the bladder wall and accumulation of sediment were common ultrasonographic findings. Contrast radiography or cystoscopy revealed findings consistent with encrusting cystitis in 3 dogs. Infection resolved in 2 dogs following surgical debridement of bladder plaques and antimicrobial administration. In 2 other dogs and 1 cat treated with antimicrobials, infection with C urealyticum resolved, but urinary tract infection with a different bacterial species developed. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that preexisting urinary tract disorders are common in dogs and cats with C urealyticum infection. Treatment with appropriate antimicrobials in combination with surgical debridement might eliminate C urealyticum infection.     

Correlation between hepatobiliary scintigraphy and surgery or postmortem examination findings in dogs and cats with extrahepatic biliary obstruction, partial obstruction, or patency of the biliary system: 18 cases (1995-2004)

OBJECTIVE: To evaluate the usefulness of serum biochemical variables and scintigraphic study results for differentiating between dogs and cats with complete extrahepatic biliary obstruction (EHO) and those with partial EHO or patent bile ducts. STUDY DESIGN: Retrospective case series. ANIMALS: 17 dogs and 1 cat. PROCEDURE: Animals that underwent hepatobiliary scintigraphy and had either surgical or postmortem confirmation of the degree of bile duct patency were included. Scintigraphic images were evaluated and biliary tracts were classified as patent, partially obstructed but patent, or obstructed. Surgery or postmortem examination was considered the gold standard for diagnosis, and compared with those findings, sensitivity and specificity of scintigraphy were calculated. RESULTS: With absence of radioactivity in the intestinal tract as the diagnostic criterion for EHO, the sensitivity and specificity of scintigraphic diagnosis were both 83% when final images were acquired at 19 to 24 hours, compared with 100% and 33%, respectively, when 180 minutes was used as the cutoff time. Animals with partial biliary obstruction had less intestinal radioactivity that arrived later than that observed in animals with patent biliary tracts. CONCLUSIONS AND CLINICAL RELEVANCE: Animals in which intestinal radioactivity has not been observed after the standard 3 to 4 hours should undergo additional scintigraphic imaging. Findings in animals with partial biliary obstruction include delayed arrival of radioactivity and less radioactivity in the intestine. Distinguishing between complete and partial biliary tract obstruction is important because animals with partial obstruction may respond favorably to medical management and should not be given an erroneous diagnosis of complete obstruction.     

Choledochal tube stenting for decompression of the extrahepatic portion of the biliary tract in dogs: 13 cases (2002-2005)

OBJECTIVE: To determine clinicopathologic features, surgical management, complications, and long-term outcome associated with diseases of the extrahepatic portion of the biliary tract treated via choledochal stent placement in dogs. DESIGN: Retrospective case series. ANIMALS: 13 dogs. PROCEDURE: Data were obtained from medical records, and follow-up information was obtained via reexamination or telephone interview with owners or referring veterinarians. RESULTS: 10 dogs had extrahepatic biliary obstruction (EHBO), 6 as a result of pancreatitis. Two dogs had rupture of the common bile duct associated with cholelithiasis. In 1 dog, a stent was placed prophylactically after gastroduodenostomy was performed for a perforated duodenal ulcer. Nine of 13 dogs survived the perioperative period and were discharged. No recurrence of EHBO or other complications developed in the discharged dogs while the stents were in place. Median follow-up period from surgery to last owner contact was 13.3 months. In 1 dog, the stent was removed endoscopically 10 months after surgery and EHBO recurred 9 months after stent removal because of cholangitis. In 4 of 5 dogs that were discharged from the hospital, in which the fate of the stent could be confirmed and the stent was secured to the duodenal wall with absorbable suture materials, the stents were passed in the feces 1 to 11 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Choledochal tube stenting is an effective method of decompression of the extrahepatic portion of the biliary tract in dogs and provides a less complex alternative to traditional cholecystoenterostomy techniques in select cases.     

Antegrade pyelography for suspected ureteral obstruction in cats: 11 cases (1995-2001)

OBJECTIVE: o determine sensitivity and specificity of radiography, ultrasonography, and antegrade pyelography for detection of ureteral obstructions in cats. DESIGN: Retrospective study. ANIMALS: 11 cats. PROCEDURE: Medical records of cats that had radiography, ultrasonography, and antegrade pyelography performed for suspected ureteral obstructions were examined. Ultrasound-guided pyelocentesis and fluoroscopic-assisted antegrade pyelography were performed on 18 kidneys in 11 cats. Obstructive ureteral lesions were confirmed in all cats by surgical or necropsy examination. Sensitivity and specificity of survey radiography, ultrasonography, and antegrade pyelography for identification of ureteral obstructions were calculated. Surgical or necropsy findings were used as the standard for comparison. RESULTS: All cats were azotemic. Mean +/- SD serum creatinine and BUN concentrations were 10.2 +/- 6.1 and 149 +/- 82 mg/dL, respectively. Fifteen of 18 ureters were found to be obstructed at surgery or necropsy. Sensitivity and specificity were 60 and 100% for radiography and 100 and 33% for ultrasonography, respectively, in identification of ureteral obstructions. Leakage of contrast material developed in 8 of 18 kidneys during antegrade pyelography and prevented diagnostic interpretation in 5 of 18 studies. For the 13 diagnostic studies, specificity and sensitivity were 100% by use of the antegrade pyelography technique. Correct identification of the anatomic location of the ureteral obstruction was obtained in 100% of diagnostic antegrade pyelography studies and in 60% of radiography or ultrasonography studies. CONCLUSIONS AND CLINICAL RELEVANCE: Antegrade pyelography can be a useful alternative in the diagnosis and localization of ureteral obstructions in azotemic cats, although leakage of contrast material may prevent interpretation of the study.     

Lower respiratory tract infections in cats: 21 cases (1995-2000)

Twenty-one lower respiratory tract infections diagnosed in cats at University of Sydney Veterinary Centre between 1995 and 2000 were identified retrospectively. Patient records were analysed to determine historical, clinical, clinicopathologic and radiographic features of lower respiratory tract infections. Response to therapy was also assessed. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Mycobacterium thermoresistible, Cryptococcus neoformans, Toxoplasma gondii, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study provides a detailed retrospective analysis of infectious lower respiratory tract disease in this population of cats.     

Smoke exposure in cats: 22 cases (1986-1997).

OBJECTIVE: To review clinical findings and clinical course for cats exposed to smoke in residential fires and to determine clinical variables that may have prognostic importance. DESIGN: Retrospective study. ANIMALS: 22 cats admitted to our veterinary teaching hospital between 1986 and 1997 with a history of smoke exposure during a residential fire. PROCEDURE: Medical records were reviewed for history, clinical signs, physical examination findings, changes in respiratory tract signs, initial hematologic analysis, treatment, results of thoracic radiography, and outcome. RESULTS: Fifteen of 22 (68%) cats were categorized in the uncomplicated group, 5 (23%) in the complicated group, and 2 (9%) were discharged after a short period because of financial considerations. Twenty (91%) cats survived, but 2 (9%) were euthanatized because of severe respiratory compromise or neurologic changes. Predominant thoracic radiographic changes were diffuse interstitial pattern (6 cats) and focal alveolar pattern (5). The majority (8/13) of cats that were stable or had improved by the day after admission had an uncomplicated clinical course while hospitalized, whereas cats that were worse on the day after admission tended to have a complicated clinical course. CONCLUSIONS AND CLINICAL RELEVANCE: Cats that survive a residential fire and are admitted to a hospital have a good chance to be discharged. Cats that do not have signs of respiratory tract dysfunction at admission probably will not develop severe respiratory complications. For cats with signs of respiratory dysfunction at admission, better prognostic information will be determined by monitoring progression of the respiratory condition on the day after admission.     

Surgical management of gallbladder mucoceles in dogs: 22 cases (1999-2003)

OBJECTIVES: To describe preoperative, surgical, and postoperative findings and determine prognostic indicators and treatment recommendations in dogs treated surgically for gallbladder mucocele. DESIGN: Retrospective study. ANIMALS: 22 client-owned dogs. PROCEDURES: Medical records of dogs with gallbladder mucoceles that were treated surgically were reviewed. History, clinical signs, results of selected clinicopathologic analyses and abdominal ultrasonography, surgical procedure performed, results of histologic examination of a liver biopsy specimen, and survival time were recorded. Follow-up information was obtained via telephone interview with owners and referring veterinarians. RESULTS: Dogs were 7 to 15 years of age and had non-specific clinical signs (vomiting, anorexia, and lethargy). Physical examination findings included icterus, signs of depression, and signs of discomfort on palpation of the abdomen. Sixteen dogs had a definitive diagnosis and 6 dogs were strongly suspected of having a gallbladder mucocele on the basis of results of abdominal ultrasonography. Fifteen dogs survived after surgery; 3 of these dogs had bile-induced peritonitis, and 4 had pancreatitis. One dog was euthanatized as a result of severe pancreatitis, and 1 was euthanatized because of acute renal failure; 5 dogs died as a result of pancreatitis, cholecystitis, or bile-induced peritonitis. Hepatic abnormalities were detected histologically in all dogs. CONCLUSIONS AND CLINICAL RELEVANCE: No predictors of survival were identified. No associations between outcome of surgical treatment (survival vs nonsurvival) and preoperative findings, biliary rupture, surgical procedure performed, results of histologic examination of the liver, or development of pancreatitis were found. Cholecystoduodenostomy and cholecystectomy appear to be acceptable treatments for gallbladder mucocele.     

Radiographic evidence of degenerative joint disease in geriatric cats: 100 cases (1994-1997)

OBJECTIVE: To determine prevalence of radiographic evidence of degenerative joint disease (DJD) in geriatric cats. DESIGN: Retrospective study. POPULATION: 100 cats > 12 years of age. PROCEDURE: One investigator reviewed radiographs and for each articulation (or group of articulations) that was visible assigned a grade of severity (0, 1, 2, 3) for DJD. Another investigator reviewed medical records and recorded signalment, environment, previous disease, diseases evident at time of radiography, FeLV vaccination and infection status, feline immunodeficiency virus serologic status, serum creatinine concentration, serum globulin concentration, and any other important findings. Associations between DJD of grade 2 or 3 and variables recorded from the medical record were determined. RESULTS: Radiographic evidence of DJD was evident in 90% of cats. Neurologic disease was associated with lesions in the lumbosacral portion of the vertebral column. Severe lesions were found in 17% of the elbow joints, but an underlying cause was not determined. CONCLUSIONS AND CLINICAL RELEVANCE: Degenerative joint disease was detected radiographically in most geriatric cats and may be an overlooked cause of clinical disease. Clinicians should be alert to the possibility that DJD is associated with neurologic signs.     

Use of low molecular weight heparin in cats: 57 cases (1999-2003)

OBJECTIVE: To determine duration of administration, complications, and frequency of aortic thromboembolism associated with administration of low molecular weight heparin (dalteparin) in cats. DESIGN: Retrospective study. ANIMALS: 57 cats treated with dalteparin PROCEDURE: Data were recorded from the medical records of cats treated with dalteparin, and owners were contacted by telephone for information regarding ease of administration and possible adverse effects. RESULTS: Dalteparin was easily administered by owners. Median dose was 99 U/kg (45 U/lb) once or twice daily. Bleeding complications were infrequent. Of 43 cats with cardiomyopathy that received owner-administered dalteparin for a median follow-up time of 172 days, 8 cats developed documented or possible arterial thromboembolism. CONCLUSIONS AND CLINICAL RELEVANCE: Dalteparin was easily administered by owners and was well tolerated by cats. Whether dalteparin administration can reduce the frequency or severity of arterial thromboembolism is not yet known.     

Peritoneal dialysis in cats with acute kidney injury: 22 cases (2001-2006)

Background: Peritoneal dialysis (PD) has been described for use in animals with acute kidney injury refractory to fluid therapy. However, no study has examined the use of PD in a large group of cats. Hypothesis: PD is an important adjunctive therapy to treat acute kidney injury in cats. Animals: The medical records of 22 cats with acute kidney injury that had received PD were examined. Animals were excluded if acute uremia was a result of postrenal causes such as uroabdomen or urethral obstruction. Methods: Medical records were reviewed for the following: indication for PD, outcome, number of cycles performed, survival time, and predialysis and postdialysis results for blood urea nitrogen (BUN), creatinine, potassium, chloride, sodium, phosphorus, total protein, and albumin concentrations, and urine output.

Results:

Indications for PD include acute‐on‐chronic kidney injury, acute kidney injury caused by toxins, bilateral ureteroliths, bilateral ureteral ligation as a complication of ovariohysterectomy, and unknown causes. The median survival time for all cats on PD was 4 days, although the median survival time for the cats that were discharged was 774 days. The most common complications were dialysate retention and sequestration of dialysate SC. There was a significant (P< .05) decrease between predialysis and postdialysis results for BUN, creatinine, potassium, phosphorus, total protein, and albumin concentrations. There was a significant (P< .05) difference in survival times between sexes. Conclusions and Clinical Importance: PD is an effective option for treatment of cats with acute kidney injury refractory to fluid therapy.     

Variables associated with outcome in dogs undergoing extrahepatic biliary surgery: 60 cases (1988-2002)

OBJECTIVE: To report clinical findings and define clinical variables associated with outcome in dogs undergoing extrahepatic biliary surgery. STUDY DESIGN: Retrospective study. ANIMALS: Sixty dogs that had extrahepatic biliary tract surgery. RESULTS: Primary diagnoses included necrotizing cholecystitis (36 dogs, 60%), pancreatitis (12 dogs, 20%), neoplasia (5 dogs, 8%), trauma (4 dogs, 7%), and gallbladder rupture from cholelithiasis without necrotizing cholecystitis (3 dogs, 5%). Bile peritonitis occurred in 19 (53%) dogs with necrotizing cholecystitis, 4 dogs with trauma, and 3 dogs with cholelithiasis without evidence of necrotizing cholecystitis. Cholecystectomy (37 dogs, 62%) and cholecystoduodenostomy (14 dogs, 23%) were the 2 most commonly performed procedures. Median hospitalization for survivors was 5 days (range, 1-15 days). There were 43 surviving dogs (72%) and 17 nonsurvivors (28%, 4 died, 13 euthanatized). Presence of septic bile peritonitis (P=.038), elevation in serum creatinine concentration (P=.003), prolonged partial thromboplastin times (PTTs; P=.003), and lower postoperative mean arterial pressures (P=.0001) were significantly associated with mortality. CONCLUSIONS: Extrahepatic biliary surgery is associated with high mortality and a relatively long hospitalization time for survivors. Cholecystectomy and cholecystoduodenostomy were the most common surgical procedures to treat the 4 major biliary problems (necrotizing cholecystitis, pancreatitis, neoplasia, and trauma) observed in this cohort of dogs. The relatively high mortality rate likely reflects the underlying diseases and their effects on the animal (septic bile peritonitis, higher serum creatinine, prolonged PTT, and lower postoperative mean arterial pressure) rather than complications of surgery. CLINICAL RELEVANCE: Septic bile peritonitis, preoperative elevated creatinine concentration, and immediate postoperative hypotension in dogs undergoing extrahepatic biliary tract surgery are associated with a poor clinical outcome. Adequate supportive care and monitoring in the perioperative period is critical to improve survival of dogs with extrahepatic biliary disease.     

Laryngeal, laryngotracheal, and tracheal masses in cats: 27 cases (1998-2003)

Medical records of 27 cats with masses of the larynx and trachea were examined. Six cats had inflammatory masses, and 21 cats had neoplastic lesions. A definitive diagnosis was reached in 22 cats with a single biopsy. The median age of the cats was 12.0 years (range 6 to 20 years). Dyspnea was the most common clinical sign. Accurate diagnoses were best obtained through direct laryngeal or tracheal examination combined with histological examination of tissue biopsies. Kaplan-Meier survival data for all inflammatory and neoplastic lesions showed a median survival of 5 days, with 7.4% of cats alive at 1 year.     

Use of fluoroscopically guided percutaneous antegrade urethral catheterization for the treatment of urethral obstruction in male cats: 9 cases (2000-2009)

Objective-To describe the technique and determine outcome for male cats with urethral obstruction treated with fluoroscopically guided percutaneous antegrade urethral catheterization (PAUC). Design-Retrospective case series. Animals-9 client-owned neutered male cats with urethral obstruction and inability to pass a retrograde urinary catheter. Procedures-Information regarding the procedure and hospitalization was obtained from medical records. Long-term follow-up was obtained via medical record review or telephone interview. Results-Diagnoses included iatrogenic urethral tear (n = 6), obstructive urethral calculi (1), urethral ulceration (1), and urethral stricture (1). Seven of the 9 procedures were successful. The 2 patients in which PAUC failed had mechanical obstructions preventing guide wire access across the urethral obstruction. Procedure times ranged from 25 to 120 minutes. No complications were noted in any patients during the procedure. One patient was euthanized because of unrelated disease. Follow-up information was available for 6 of 8 surviving patients. No complications that could be directly attributed to the procedure were noted. All 6 patients had a perineal urethrostomy performed 0 days to 6 weeks following the procedure because of reobstruction of the lower urinary tract. None of these patients had documented urethral strictures and none had recurrence of clinical signs following perineal urethrostomy. Conclusions and Clinical Relevance-Results suggested that PAUC can be a simple, rapid, minimally invasive, and safe technique to facilitate transurethral catheterization in select cases. Patients with iatrogenic urethral tears may be good candidates. Patients with impacted urethral calculi, severe strictures or ulcerations, or a nondistended urinary bladder may be less amenable to PAUC.     

Lomustine for treatment of mast cell tumors in cats: 38 cases (1999-2005)

OBJECTIVE: To determine clinical activity and toxic effects of lomustine when used to treat cats with mast cell tumors (MCTs). DESIGN: Retrospective case series. ANIMALS: 38 cats with measurable, histologically or cytologically confirmed MCTs treated with lomustine at a dosage > or = 50 mg/m(2). PROCEDURES: Medical records were reviewed to determine response to treatment and evidence of drug toxicoses. The Kaplan-Meier method was used to estimate remission duration. RESULTS: 26 cats had cutaneous MCTs, 7 had MCTs of the mesenteric lymph nodes, 2 had gastrointestinal tract MCTs, 2 had hepatic MCTs, and 1 had MCTs involving multiple organs. Targeted lomustine dosage was 50 mg/m(2) in 22 cats and 60 mg/m(2) in 16 cats. Median administered dosage of lomustine was 56 mg/m(2) (range, 48 to 65 mg/m(2)), and median number of doses administered was 2 (range, 1 to 12). Seven cats had a complete response and 12 had a partial response, for an overall response rate of 50%. Median response duration was 168 days (range, 25 to 727 days). The most common toxicoses were neutropenia and thrombocytopenia. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that lomustine had activity against MCTs in cats and was well tolerated. Further, findings suggested that treatment with lomustine should be considered for cats with MCTs for which local treatment is not an option.     

Outcome of ameroid constrictor occlusion of single congenital extrahepatic portosystemic shunts in cats: 12 cases (1993-2000)

OBJECTIVE: To determine postoperative (< or = 6 days), short-term (< or = 90 days), and long-term (> or = 6 months) outcomes of cats undergoing ameroid constrictor occlusion of single congenital extrahepatic portosystemic shunts (PSS) and identify factors associated with outcome. DESIGN: Retrospective study. ANIMALS: 12 cats. PROCEDURE: Cats with single congenital PSS that underwent surgical placement of ameroid constrictors were identified. Follow-up information was obtained through telephone interviews and facsimile correspondence with referring veterinarians and owners. Results-All cats survived the surgery and were discharged from the hospital. One cat had seizures during the postoperative period. Five cats were clinically normal during follow-up evaluations within 90 days after the surgery. Long-term follow-up information was available for 9 cats. Three were clinically normal, 4 had been euthanatized because of progressive neurologic disease, and 2 had neurologic abnormalities that could not be controlled with medication. Four of 7 cats with continued or recurrent neurologic abnormalities 1 or more months after surgery had normal scintigraphic or hepatic function test results 2 to 6 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the long-term outcome of ameroid constrictor occlusion of PSS in cats is poor. Owners of older cats and cats with preexisting neurologic signs should be made aware of the potential for a poor outcome when considering surgical correction of this disease.