Hepatotoxicity of stanozolol in cats.

OBJECTIVE: To determine hepatotoxicity of stanozolol in cats and to identify clinicopathologic and histopathologic abnormalities in cats with stanozolol-induced hepatotoxicosis. DESIGN: Clinical trial and case series. ANIMALS: 12 healthy cats, 6 cats with chronic renal failure, and 3 cats with gingivitis and stomatitis. PROCEDURES: Healthy cats and cats with renal failure were treated with stanozolol (25 mg, i.m., on the first day, then 2 mg, p.o., q 12 h) for 4 weeks. Cats with gingivitis were treated with stanozolol at a dosage of 1 mg, p.o., every 24 hours. RESULTS: Most healthy cats and cats with renal failure developed marked inappetence, groomed less, and were less active within 7 to 10 days after initiation of stanozolol administration. Serum alanine transaminase (ALT) activity was significantly increased in 14 of 18 cats after stanozolol administration, but serum alkaline phosphatase activity was mildly increased in only 3. Four cats with serum ALT activity > 1,000 U/L after only 2 weeks of stanozolol administration had coagulopathies; administration of vitamin K resolved the coagulopathy in 3 of the 4 within 48 hours. All 18 cats survived, and hepatic enzyme activities were normal in all cats tested more than 4 weeks after stanozolol administration was discontinued. Two of the 3 cats with gingivitis developed evidence of severe hepatic failure 2 to 3 months after initiation of stanozolol treatment; both cats developed coagulopathies. Histologic evaluation of hepatic biopsy specimens from 5 cats revealed diffuse hepatic lipidosis and cholestasis without evidence of hepatocellular necrosis. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that stanozolol is hepatotoxic in cats.

Effect of stanozolol on body composition, nitrogen balance, and food consumption in castrated dogs with chronic renal failure.

OBJECTIVE: To determine the effect of stanozolol on body composition, nitrogen balance, and food consumption in castrated dogs with chronic renal failure. DESIGN: Blinded crossover trial. ANIMALS: 22 castrated Beagles with experimentally induced chronic renal failure. PROCEDURE: Dogs were divided into 2 groups of 11 dogs each. During each of two 6-week treatment periods, dogs in 1 group received stanozolol, and those in the other group received a control agent. Nitrogen balance, body composition, and food consumption were determined. RESULTS: During administration of stanozolol, the amount of food consumed per dog, lean body mass, and nitrogen balance increased. Stanozolol did not have a significant effect on body fat, bone mineral content, or food consumption per kilogram of body weight. CLINICAL IMPLICATIONS: For dogs with mild-to-moderate, nonuremic, experimentally induced, chronic renal failure, stanozolol had positive effects on nitrogen balance and lean body mass.

Clinical and clinicopathologic abnormalities in greyhounds with cutaneous and renal glomerular vasculopathy: 18 cases (1992-1994)

OBJECTIVE: To determine clinical signs and clinicopathologic abnormalities in Greyhounds with cutaneous and renal glomerular vasculopathy and to determine whether there were any differences between dogs with and without renal azotemia. DESIGN: Retrospective study. ANIMALS: 18 Greyhounds. PROCEDURE: Results of CBC, serum biochemical analyses, urinalyses, coagulation tests, tests of RBC morphology, bacterial culture of blood samples, and serologic tests for Rickettsia rickettsii, Ehrlichia canis, E platys, and Leptospira interrogans were reviewed. Glomerular filtration rates and urine protein:creatinine ratios were determined in most dogs. t-Tests and a test of equality of proportions were used to compare dogs that developed renal azotemia with dogs that did not. RESULTS: None of the dogs was bacteremic or had serologic evidence of infectious disease. Ten dogs had renal azotemia, 16 had anemia, 11 had hypoalbuminemia, and 18 developed thrombocytopenia. Compared with dogs without renal azotemia, dogs with renal azotemia had significantly lower mean platelet count, hematocrit, and serum albumin concentration and significantly higher mean neutrophil count and creatine kinase activity. All 10 dogs with renal azotemia died or were euthanatized; 7 of 8 dogs without azotemia survived. CLINICAL IMPLICATIONS: Greyhounds with cutaneous and renal glomerular vasculopathy that developed renal azotemia had evidence of more severe systemic disease than did dogs that did not have azotemia and, despite supportive treatment, had a poorer prognosis.

Glomerular ultrastructural lesions of idiopathic cutaneous and renal glomerular vasculopathy of greyhounds.

Idiopathic cutaneous and renal glomerular vasculopathy (CRGV) (Alabama rot) is a potentially fatal disease of unknown etiology that affects the skin and kidneys of racing- and training-age Greyhounds. Ultrastructural examinations were performed on two healthy control Greyhounds and 12 Greyhounds diagnosed with CRGV based on the presence of characteristic, well-demarcated cutaneous ulcers of the extremities (12/12), thrombocytopenia (< 200,000 platelets/dl) (12/12), and acute renal insufficiency (BUN > 40 mg/dl, serum creatinine > 2.0 mg/dl) (7/12). Early glomerular ultrastructural changes included endothelial swelling, detachment, and necrosis; membranous whorl formation; and platelet adhesion and aggregation. Some capillaries were occluded with aggregated platelets, cellular fragments, and fibrin. Later changes included narrowing of capillary lumina and thickening of glomerular capillary walls by subendothelial accumulation of flocculent, amorphous, variable electron-dense material and occasionally erythrocytes, cellular processes, and fibrin. Glomerular endothelial cells were increased in number and plump, with villouslike cytoplasmic projections. Mesangial cell cytoplasmic processes occasionally were interposed between the endothelium and the basement membrane. No etiologic agents or electron-dense deposits typical of immune complexes were observed. Although the specific etiology was not determined, the ultrastructural changes suggest that glomerular endothelial damage is an important early event in the pathogenesis of CRGV.

Gross and microscopic lesions of 230 Kansas greyhounds.

Two hundred thirty greyhounds from Kansas were submitted to Kansas State University for necropsy to identify and document their diseases. Sex distribution was 124 females (1 spayed) and 106 males (1 castrated). Age range was 5 days-150 months. The mean body, heart, and liver weights for adult dogs (> 12 months) were 30 kg, 367 g, and 1,019 g, respectively. Greyhounds were divided into six groups by histories: skeletal injuries, 24 (10%); nonskeletal injuries, 23 (10%); old age (mean = 89 months), 25 (11%); poor performers, 83 (36%); sick, 68 (30%); and no history, 7 (3%). Gross lesions by system were as follows: skin, 85 (37%); lung, 13 (6%); skeletal, 36 (16%); gastrointestinal, 55 (23.9%); central nervous system, 3 (1%); thyroid, 5 (2%); cardiovascular and hemopoietic, 36 (16%); spleen, 30 (13%); male reproductive, 13 (12%); kidney, 9 (4%); liver, 7 (3%); and no gross lesions, 23 (10%). Correlation of the histories to the gross lesions showed that poor performers had the largest number with no gross lesions, the skeletal injury and sick groups had more gastrointestinal changes, and the nonskeletal injury and sick groups had most of the male reproductive abnormalities. Microscopic lesions of the 6 tissues examined were as follows: lung, 21 (9%); small intestine, 15 (6.5%); brain, 6 (3%); heart, 9 (4%); kidney, 57 (24.3%); liver, 26 (11.3%); and no microscopic lesions, 131 (57%).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of bacterial infection and castration on prostatic tissue zinc concentration in dogs.

An Escherichia coli bacterial prostatitis was experimentally induced to determine the effect of bacterial infection on prostatic tissue zinc concentrations in castrated and gonadally intact male dogs. Five of the 22 mixed-breed dogs (group 1) had no culture evidence of infection 2 weeks after the instillation of bacteria into the prostate gland. The remaining 17 infected dogs were allotted to 2 groups; 1 group of dogs was subjected to castration (group CA, 7 dogs), and the other group of dogs was subjected to sham operation (group SO, 10 days). The groups were divided into groups of dogs with prostatic infection at necropsy (groups CA-I and SO-I), and those dogs without prostatic infection at necropsy (groups CA-N and SO-N). Urine, prostatic fluid, and prostatic tissue (week 0, 7, +/- 12) specimens were obtained for bacteriologic culturing to determine whether prostatic infection was present. Prostatic tissue was obtained at necropsy (week less than 6, 7, or 12) for analysis of zinc concentration by atomic absorption spectrophotometry. The logarithmic mean prostatic tissue zinc concentrations were compared between groups. Group CA had a significantly lower prostatic zinc concentration than all other groups. Zinc concentrations were not statistically different between any of the other groups. Castration did decrease the prostatic tissue concentration of zinc, a known natural antibacterial factor. However, resistance to infection and resolution of infection were not correlated with prostatic tissue zinc concentrations in this experimental model.

Effects of castration on chronic bacterial prostatitis in dogs.

An Escherichia coli bacterial prostatitis was experimentally induced in dogs to determine the effect of castration on chronic bacterial prostatitis. Two weeks after instillation of bacteria directly into the prostate gland, 17 of 22 adult mixed-breed male dogs had positive urine or prostatic fluid cultures or both. Seven of the 17 dogs were randomly chosen to be castrated, and 10 of the 17 served as sham-operated controls. At weekly intervals, urine was obtained from 17 dogs for aerobic microbiologic culturing. At each week, dogs with no bacterial growth in the cultured urine had prostatic fluid collected for aerobic microbiologic culture. Dogs with negative urine, prostatic fluid, and prostatic tissue needle biopsy culture results at week 7 were euthanatized. For remaining dogs, weekly cultures were continued until the dogs were euthanatized at week 12. None of the 7 castrated dogs and 6 of the 10 dogs subject to sham operation had prostatic infection at the time of necropsy. The castrated dogs had a mean infection duration of 4.2 weeks, which was statistically shorter than the 9.5-week mean duration of infection in the sham-operated controls. Cultures of prostatic tissue obtained immediately after euthanasia correlated 100% with urine and prostatic fluid cultures taken before euthanasia. All of the 6 dogs with positive prostatic cultures at termination had moderate to marked lymphoplasmacytic chronic prostatitis. The 11 dogs that were not infected at the end of the study had normal to moderate lymphoplasmacytic chronic prostatitis on histologic examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Generalized demodicosis in a cat responsive to amitraz.

Generalized demodicosis was diagnosed in a 14-year-old castrated male domestic short-hair cat. No underlying disease was detected. The cat responded incompletely or poorly to commonly recommended treatment, but responded well to total body dipping with 0.0125% amitraz at weekly intervals.

Adrenal function testing in the cat: the effect of low dose intravenous dexamethasone administration.

The plasma cortisol responses of 11 normal cats to intravenous dexamethasone at a dose rate of 0.01 mg kg-1 whole bodyweight, were evaluated. Mean plasma cortisol concentrations decreased significantly (P less than 0.01) at three hours and eight hours following dexamethasone administration. Results of this study indicate that plasma cortisol levels are significantly decreased for at least eight hours following low dose intravenous dexamethasone administration in normal cats.