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Comorbidities: Managing Cats That Have

Coexistent Cardiac Disease and Extracardiac

Disorders

Key Points

• Identification of acute, transient exacerbations of chronic conditions (cardiac, renal, or other), and differentiation of these from
end-stage disease, are essential for accurate prognosis and treatment of cardiac and extracardiac disorders.
• The new onset of a gallop sound during intravenous fluid therapy in a hospitalized cat with heart disease should raise the
concern of impending congestive heart failure, and fluid rate/type should be adjusted accordingly.
• Repositol glucocorticoid injections expand cats’ plasma volume, possibly causing iatrogenic congestive heart failure if cats
have pre-existing heart disease.
• Diuretic resistance may explain a persistence of congestive heart failure, and escalating dosages of diuretics should prompt an
investigation for diuretic resistance, as well as a reassessment of the diagnosis of congestive heart failure if any uncertainty
exists.
• Administration of diuretics and parenteral fluids simultaneously is self-defeating. The clinician should decide whether the
patient needs more intravascular volume or less, and choose therapy accordingly (e.g., decrease diuretic dose rather than
begin IV fluids).
• Triggers that may cause congestive heart failure in cats with previously compensated heart disease include acute salt ingestion
(canned fish, other salty foods), overconsumption of commercial treats, repositol glucocorticoid injections, acute tachycardia-
inducing events (general anesthesia, veterinary appointments), and parenteral fluids. Identifying such triggers is important
because the long-term prognosis is likely better than when congestive heart failure occurs as a sole result of natural heart
disease progression.

INTRODUCTION patient with concurrent illness where diuretic adminis-
tration could be detrimental: what is the best way to
In many feline patients, heart disease exists simultane- manage a patient’s heart failure without excessive impact
ously with an extracardiac disorder and treatment of on the extracardiac disorder? Perhaps the most common
either one may be detrimental to the other. Common example of this dilemma is the cat with concurrent con-
examples include disorders where fluid therapy may be gestive heart failure and chronic kidney disease, where
required (e.g., chronic kidney disease, dehydration of diuretic administration increases levels of blood urea
any cause) or where glucocorticoids are the treatment of nitrogen and creatinine to a level that raises concern, yet
choice (e.g., inflammatory bowel disease, allergic airway where the reduction or cessation of diuretics would
disease, chronic dermatopathies). In both of these exam- trigger recurrence of pulmonary edema/pleural effu-
ples, the risk of precipitating congestive heart failure sion. These difficult situations are discussed in this
iatrogenically is a legitimate concern in the cat with chapter, with recommendations and discussion of
coexisting heart disease. Another layer of this conun- methods to find an appropriate balance between such
drum exists when treating congestive heart failure in a commonly occurring, but often opposing, disorders.

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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