Page 182 - Feline Cardiology

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Dilated Cardiomyopathy

Key Points

• Dilated cardiomyopathy is an adult onset myocardial disease characterized by systolic dysfunction.
• Dilated cardiomyopathy was most commonly associated with taurine deficiency but this is now rarely observed in cats on a
balanced, feline diet. The etiology of many cases is unknown.
• Affected cats that are eating a taurine-deficient diet may respond well to taurine supplementation.

INTRODUCTION supplemented with taurine, but it is still occasionally
diagnosed even in cats on a normal diet. Dilated cardio­
Dilated cardiomyopathy is an adult onset primary myo­ myopathy associated with taurine deficiency is still
cardial disease characterized by dilation of the left ventri­ observed in cats receiving unbalanced diets (vegetarian,
cular lumen and decreased systolic myocardial function. certain homemade diets, diets designed for other species
Occasionally dilated cardiomyopathy is referred to by [i.e., dog food]). Interestingly, there is some indication
other names, including congestive cardiomyopathy or that there may be a heritable component to the develop­
myocardial systolic dysfunction. Dilated cardiomyopathy ment of dilated cardiomyopathy associated with taurine
used to be the most common form of feline myocardial deficiency with some families at greater risk of develop­
disease until it was determined that many cats suffered ing cardiomyopathy than others (Lawler et al. 1993;
from taurine deficiency due to insufficient levels of Novotny et al. 1994).
taurine in commercial pet food (Pion et al. 1987). It is Additionally, feline dilated cardiomyopathy is still rec­
now considered an uncommon feline myocardial disease. ognized in small numbers of cats eating an appropriate
diet; the etiology of dilated cardiomyopathy in these
ETIOLOGY, PATHOPHYSIOLOGY, AND cases is unknown. A recent report of feline cardiomy­
GROSS PATHOLOGY opathy that included 11 cats with dilated cardiomyopa­
thy did not find any to be associated with taurine
Etiology deficiency (Ferasin et al. 2003).
The prevalence of dilated cardiomyopathy in the cat is Viral nucleic acid and histopathologic findings con­
not well known but it is certainly much less than that of sistent with myocarditis were identified in a small
hypertrophic cardiomyopathy. One report of the preva­ number of cats with dilated cardiomyopathy; therefore,
lence of dilated cardiomyopathy in the late 1990s found an infectious etiology has been suggested for some cases
a prevalence of about 5–7% (Fox et al. 1999). The preva­ (Meurs et al. 2000). Viral myocarditis is also associated
lence of this form of cardiomyopathy has significantly with the development of dilated cardiomyopathy in
decreased now that commercial pet foods are properly humans and other species (Hare 2008).

Feline Cardiology, First Edition. Etienne Côté, Kristin A. MacDonald, Kathryn M. Meurs, Meg M. Sleeper.
© 2011 John Wiley & Sons, Inc. Published 2011 by John Wiley & Sons, Inc.

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