Page 134 - Problem-Based Feline Medicine

126 PART 3 CAT WITH SIGNS OF HEART DISEASE

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● Peritoneal–pericardial diaphragmatic hernia (p 153)
A murmur may or may not be heard. The cardiac silhouette is extremely enlarged on thoracic radi-
ographs. Many cats are asymptomatic, but some cats present for gastrointestinal signs or respira-
tory distress.
METABOLIC
● Hypertensive heart disease*** (p 133)
A systolic murmur, tachycardia and/or gallop rhythm may be heard. Hypertension in cats is most
commonly secondary to chronic renal failure or hyperthyroidism. Essential or idiopathic hyperten-
sion is less common.
● Hyperthyroid heart disease*** (p 131)
A systolic murmur, tachycardia and/or gallop rhythm may be heard. Hyperthyroid heart disease is
associated with other clinical signs of hyperthyroidism including weight loss, restlessness, palpa-
ble thyroid nodule, low frequency of gastrointestinal signs and is seen in older cats.
● High cardiac output state* (p 138)
A murmur, gallop rhythm or tachycardia may be heard on auscultation. It can be caused by ane-
mia secondary to other disease states or hyperthyroidism. The heart size may be variable
depending on the disease or the chronicity of the anemia.

NEOPLASTIC
● Neoplasia** (p 137)
Displaced or muffled heart sounds can be caused by neoplasia from a mass or effusion. Lymphoma
is the most common neoplasia seen in cats and occasionally infiltrates the myocardium.
INFECTIOUS
● Infectious
Infectious diseases can rarely cause secondary cardiomyopathies in cats. Most cats die unexpect-
edly and/or are systemically ill. Etiologies suspected are viral (feline infectious peritonitis), sec-
ondary bacterial or parasitic (toxoplasmosis). Bacterial (pyothorax, myocarditis, pericarditis) and
viral (myocarditis, pericarditis) infections can cause displaced or muffled heart sounds and/or
arrhythmias (p 157).
● Heartworm disease* (p 139)
Dirofilaria immitis (heartworm disease) in cats is less common than in dogs. Cardiac signs are
variable and may include signs of right heart failure, gallop rhythm or murmurs. Coughing, vomit-
ing or sudden death may also occur. Heartworm disease in cats is more common in male cats, out-
door cats, and occurrence depends on geographical location.
IDIOPATHIC

● Hypertrophic cardiomyopathy*** (p 128)
A systolic murmur varying in location, arrhythmia and/or gallop rhythm may be heard. It is the
most common form of heart disease in cats and occurs usually in male and middle-aged cats. It
can also be seen in young (less than 1 year of age) cats and older cats. It may be genetically trans-
mitted in some pure-breed cats. The heart may or may not be enlarged on radiographs.