Heart failure occurs when the heart no longer pumps sufficient blood to meet the metabolic demands of the body. This triggers a complex sequence of events that can lead to fluid build-up (congestion) within the lungs (pulmonary edema) or around the lungs (pleural effusion).  This fluid build-up produces the symptoms recognized in heart failure:

• Reluctance to move
• Decreased appetite
• Difficulty breathing
• Vomiting
• Abdominal distension (uncommon in cats)

There are many possible causes for heart disease in cats, but emergency treatment for congestive heart failure is independent of the underlying disease. The goal of emergency therapy is to relieve the clinical signs and prolong survival by improving oxygenation, reducing pulmonary edema, and optimizing cardiac output.

Initial management will depend on the severity of clinical signs and usually includes:

• Oxygen supplementation via oxygen cage, nasal catheter, or oxygen mask
• Lasix (furosemide) to reduce fluid build-up
• Sedation to reduce stress may be beneficial and necessary for many patients
• Pleurocentesis may be needed to stabilize the patient
• Nitroglycerine ointment to reduce cardiac workload
• Benazepril to improve cardiac output by reducing vascular resistance

Once stable enough for handling, a thorough physical examination and diagnostic tests will be performed. Testing may include:

• Radiographs
• Chemistry panel/T4 and complete blood count 
• Blood pressure measurement
• ECG – if arrhythmia is detected
• Ultrasound – ultimately needed to determine underlying structural heart disease, develop a long-term management strategy and provide a prognosis

Long-term management of CHF includes treating underlying diseases such as hyperthyroidism and hypertension, use of Lasix to manage volume overload, and benazepril to reduce cardiac workload.  Aspirin may be useful in prevention of blood clots. Potassium supplementation or the addition of spironolactone may be needed with long term use of Lasix.

All feline heart disease has the potential to progress, resulting in the development of clinical signs consistent with congestive heart failure. Treatment of congestive heart failure can result in remission of clinical signs, but relapses are to be expected.  Measures can be taken to help reduce the likelihood/rate of relapse.

• Reduce stress and limit exercise
• Diet of low sodium food (avoid pounce treats, canned tuna, high sodium broths)
• Prevent drug reactions by using lowest effective dose of medication
• Be alert to signs of complication (anorexia, difficulty breathing, vomiting, weakness)
• Schedule regular appointments to monitor kidney function (affected by heart medications) and radiographic changes in the lungs.

Relapses:

Often increasing dose of diuretic will control signs; however, improving cardiac function by improving filling, correcting arrhythmias, improving contractility, and vasodilatation will more likely result in improved survival.