Page 261 - Feline Cardiology

268 Section G: Congestive Heart Failure

(46/112 cats: 41%), left or right atrium (12/112 cats: HISTORY AND CHIEF COMPLAINT
11%), and less frequently in renal arteries, iliac arteries,
carotid arteries, and pulmonary and hepatic vessels (SK
Liu 1970). These “red” thromboemboli consist of fibrin Key Points
meshes that entrap red blood cells and leukocytes.
Pathologic abnormalities of the heart depend on the • Nonspecific abnormalities noted on history of cats
etiology of the heart failure and are discussed in specific diagnosed with heart failure include: weight loss,
chapters. inappetence, and lethargy.
• Dyspnea and tachypnea are the most common chief
SIGNALMENT complaints of cats presenting with heart failure.

Key Points Typical abnormalities noted by the owners of cats with
heart failure include weight loss, lethargy, and hyporexia
• There is a wide age distribution of cats with heart or anorexia. A majority of cats (72% in one study) with
failure, ranging from less than 1 year to geriatric, which heart failure have a history of inappetence (Torin et al.
reflects the wide age distribution of the underlying
2007). Cats may be more reclusive and less interactive
Congestive Heart Failure • The domestic shorthair is the most common breed of cat pnea are the most common complaints, and owners may
cardiac disorders.
with other pets or family members. Dyspnea and tachy-
diagnosed with heart failure, likely because it represents
describe abnormalities including coughing, vomiting
a greater proportion of the feline population.
(owners may confuse with coughing), open mouth
breathing, tachypnea, or dyspnea. Episodic weakness or
Because both congenital and developmental heart dis-
Some cats may have had a chronic history of a heart
eases may lead to heart failure, there is a wide distribu- collapse may be noted by obtaining a careful history.
murmur, especially cats with congenital heart disease or
tion of ages ranging from kitten to geriatric. According hypertrophic cardiomyopathy. Cats with congenital
to a sentinel study in the 1960s, 43% of cats dying from heart disease may have a history of poor growth (Liu et
heart failure were less than 1 year of age and less than al. 1970). History of a previous thromboembolic event
1% were over 16 years of age (Liu et al. 1970). Seventeen may include an episode of pain and lameness/paresis
percent of the cats in this study had congenital heart and is relatively common in cats with severe heart
disease, and a majority (77%) of them died of heart disease. Sometimes the first clinical sign is sudden
failure by 1 year of age. The most common breed diag- cardiac death, which was the presenting complaint in
nosed was the domestic shorthair (63%) followed by 25% of cats dying of heart failure (Liu et al. 1970).
Siamese (32%), which were overrepresented in both
congenital and acquired disease categories. There was no PRECIPITATING FACTORS THAT MAY
sex predisposition for congenital or acquired disease CONTRIBUTE TO CONGESTIVE HEART FAILURE
leading to heart failure. Another study reported that the
most common cause of ascites in cats less than 1 year of
age was congenital heart disease (Wright et al. 1999). Key Points
However, when analyzing all cats diagnosed with ascites
secondary to right heart failure, there was even distribu- • A precipitating event is common in cats presenting
tion of age and sex (Wright et al. 1999). Similar to the with heart failure. Recent fluid administration, general
previous study, the domestic shorthair was the most anesthesia, or repositol corticosteroid administration are
common breed diagnosed with ascites and right heart the most common antecedent events.
failure (63%) (Wright et al. 1999). In cats with HCM, • Diseases that increase circulating blood volume, such as
there was no difference in age, sex, or breed among significant anemia, may precipitate heart failure in cats
clinical groups of heart failure, arterial thromboembo- with underlying heart disease.
lism, syncope, or subclinical disease (Rush et al. 2002). • Hyperthyroidism is another cause of high output heart
In summary, heart failure is evenly distributed among disease, and may contribute to development of heart
failure, especially in cats with underlying heart disease.
all age groups of cats, with no sex predilection beyond • Isolated systemic hypertension does not typically lead to
that of the underlying cardiac disorder. The domestic heart failure, but may contribute to diastolic dysfunction
shorthair is overrepresented for development of heart in cats with underlying heart disease.
failure.