Objective—To determine clinical features of dilated
cardiomyopathy (DCM) in Great Danes and to determine
whether DCM is familial in this breed.
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
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
Objective—To determine the usefulness of echocardiography
in the diagnosis of heartworm disease in cats and to compare this modality with other tests.
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)
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)
Objective—To determine whether plasma concentrations
of tumor necrosis factor-α (TNF-α) are increased
in cats with congestive heart failure (CHF) secondary
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
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)