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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine clinical features of dilated cardiomyopathy (DCM) in Great Danes and to determine whether DCM is familial in this breed.

Design—Retrospective study.

Animals—17 Great Danes with DCM.

Procedure—Medical records of Great Danes in which DCM was diagnosed on the basis of results of echocardiography (fractional shortening < 25%, endsystolic volume index > 30 ml/m2 of body surface area) were reviewed. Pedigrees were obtained for affected animals, as well as for other Great Danes in which DCM had been diagnosed.

Results—Dilated cardiomyopathy appeared to be familial and was characterized by ventricular dilatation, congestive heart failure (left-sided or biventricular), and atrial fibrillation. Pedigree analysis suggested that DCM was inherited as an X-linked recessive trait, but the mode of inheritance could not be definitively identified.

Conclusions and Clinical Relevance—Results suggest that DCM may be an X-linked recessive trait in Great Danes. Thus, dogs with DCM probably should not be used for breeding, and female offspring of affected dogs should be used cautiously. Male offspring of affected females are at an increased risk of developing DCM and should be evaluated periodically for early signs of disease. Results of pedigree analysis were preliminary and should be used only as a guide for counseling breeders, rather than as a basis for making breeding decisions. (J Am Vet Med Assoc 2001;218:729–732)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the usefulness of echocardiography in the diagnosis of heartworm disease in cats and to compare this modality with other tests.

Design—Retrospective study.

Animals—43 cats with heartworm infection that had echocardiographic examinations at 2 veterinary teaching hospitals between 1985 and 1997. Twenty-two of these 43 cats also underwent radiography of the thorax and heartworm antibody and heartworm antigen testing.

Procedure—Cats were determined to be infected with Dirofilaria immitis infection on the basis of 1 or more of the following findings: positive modified Knott or antigen test result, echocardiographic evidence of heartworm disease, or confirmation of the disease on postmortem examination. The percentage of echocardiographs in which heartworms were evident was compared with the percentage of radiographs in which pulmonary artery enlargement was evident and results of antigen or antibody tests in cats in which all tests were performed.

Results—Overall, heartworms were detectable by use of echocardiography in 17 of 43 cats, most often in the pulmonary arteries. In the 22 cats in which all tests were performed, antibody test results were positive in 18, antigen test results were positive in 12, and pulmonary artery enlargement was evident radiographically and heartworms were identifiable echocardiographically in 14. Heartworm infection was diagnosed exclusively by use of echocardiography in 5 cats in which the antigen test result was negative.

Conclusions and Clinical Relevance—Although echocardiography was less sensitive than antigen testing, it was a useful adjunctive test in cats that had negative antigen test results in which there was a suspicion of heartworm disease. The pulmonary arteries should be evaluated carefully to increase the likelihood of detection of heartworms echocardiographically. ( J Am Vet Med Assoc2001;218:66–69)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To devise a technique for gradual occlusion of the caudal vena cava in dogs and determine effects of complete occlusion of the caudal vena cava.

Animals—8 mixed-breed hounds that weighed between 25 and 30 kg.

Procedure—Baseline evaluation of dogs included serum biochemical analyses and determination of glomerular filtration rate (GFR) with dynamic renal scintigraphy and plasma clearance analysis. An occluder was placed around the vena cava in the region cranial to the renal veins. The occluder was attached to a vascular access port. The vena cava was gradually occluded over 2 weeks. The GFR was measured every 2 weeks after surgery, and venograms were performed every 3 weeks after surgery. Blood samples were collected every 48 hours for the first week and then weekly thereafter to measure BUN and creatinine concentrations and activities of alanine transaminase, alkaline phosphatase, and creatinine kinase. Dogs were euthanatized 6 weeks after surgery, and tissues were submitted for histologic examination. The GFR and biochemical data were compared with baseline values.

Results—Gradual occlusion of the caudal vena cava was easily and consistently performed with this method, and adverse clinical signs were not detected. Formation of collateral vessels allowed overall GFR to remain constant despite a decrease in function of the left kidney. Measured biochemical values did not deviate from reference ranges.

Conclusions and Clinical Relevance—Gradual occlusion of the caudal vena cava may allow removal of adrenal gland tumors with vascular invasion that would otherwise be difficult or impossible to resect. (Am J Vet Res 2003;64:1347–1353)

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in American Journal of Veterinary Research

Abstract

Objective—To determine whether plasma concentrations of tumor necrosis factor-α (TNF-α) are increased in cats with congestive heart failure (CHF) secondary to cardiomyopathy.

Animals—26 adult cats with CHF and cardiomyopathy and 9 healthy control cats.

Procedure—Plasma concentrations of TNF-α were measured in cats with CHF and cardiomyopathy. Tumor necrosis factor-α was measured by quantifying cytotoxic effects of TNF-α on L929 murine fibrosarcoma cells.

Results—Concentrations of TNF-α were increased (0.13 to 3.6 U/ml) in 10 of 26 cats with CHF but were undetectable in the other 16 cats with CHF and all control cats. In 20 of 26 cats with CHF, right-sided heart failure (RHF) was evident; TNF-α concentrations were increased in 9 of these 20 cats. The remaining 6 cats had left-sided heart failure (LHF); TNF-α concentrations were increased in only 1 of these cats. Age of cats with LHF (mean ± SD, 12.1 ± 6.2 years) was not significantly different from age of the cohort with RHF (10.5 ± 5.2 years). Body weight of cats with increased TNFα concentrations (5.4 ± 1.8 kg) was not significantly different from body weight of cats with CHF that did not have measurable concentrations of TNF-α (4.7 ± 1.6 kg).

Conclusionss and Clinical Relevance—Concentrations of TNF-α were increased in many cats with CHF. Cats with RHF were most likely to have increased TNF-α concentrations. Increased plasma concentrations of TNF-α in cats with CHF may offer insights into the pathophysiologic mechanisms of heart failure and provide targets for therapeutic interventions. (Am J Vet Res 2002;63:640–642)

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in American Journal of Veterinary Research