Page 147 - Problem-Based Feline Medicine

9 – THE CAT WITH ABNORMAL HEART SOUNDS AND/OR AN ENLARGED HEART 139

Differential diagnosis Cats with symptoms may show open-mouth breathing
and/or cyanosis after mild to moderate exercise.
Cardiomyopathy.
Hyperthyroidism. Diagnosis

Treatment Thoracocentesis findings
Aspiration of the chest fluid commonly yields a milky
Treatment should be directed towards the underlying
white fluid (can be slightly pink). This fluid may feel
disease.
greasy.
Refer to page 305 (The Cat With Weight Loss and a
Determination of fluid triglyceride level with a paired
Good Appetite) for hyperthyroidism and page 526 (The
serum triglyceride sample (obtained at the same time)
Anemic Cat) for anemia.
always reveals a higher triglyceride level in the chest
If congestive heart failure is present, with concurrent fluid.
myocardial failure refer to section on dilated cardiomy- Cytological evaluation usually reveals a homogeneous
opathy, page 151. population of mature lymphocytes and neutrophils.
If congestive heart failure is present without myocar- Bacterial culture is negative.
dial failure refer to section on hypertrophic cardiomy-
opathy, page 128. Radiographic findings
Marked pleural effusion.
Prognosis
Elevated trachea.
Varies depending on disease process.
Obscured cardiac silhouette.
CHYLOUS EFFUSION* Collapsed lung lobes.
Electrocardiographic findings
Classical signs
Normal.
● Dyspnea/tachypnea.
Abnormalities may be seen if there is concurrent heart
● Anorexia.
disease.
● Lethargy.
Echocardiographic findings
See main reference page 77 (The Cat With Hydrothorax).
Many cats have a normal echocardiogram.
Clinical signs In some cases, chylous effusion may be secondary to
severe heart disease of any etiology.
Chylous effusion in cats is often of unknown cause.
The most common causes are right heart failure from
cardiomyopathy or heartworm or mediastinal neoplasia HEARTWORM DISEASE*
associated with lymphoma or thymoma. Chylothorax
may occur secondary to a thrombus associated with an Classical signs
indwelling jugular catheter.
● Respiratory distress.
Dyspnea and tachypnea are common presenting clini- ● Coughing.
cal signs. Commonly an abdominal respiratory compo- ● Vomiting.
nent is seen. ● Sudden death.
The presence of chest fluid results in muffled
heart sounds and absent lung sounds in the ventral Clinical signs
thorax.
Many cats are asymptomatic.
Cats develop poor appetite when a large amount of
fluid is present (> ~150 ml). Sudden death is seen in some cases.