Understanding heart disease & congestive heart failure in pets.

When it comes to the health of our pets, the majority of pet owners take for granted that our pet’s heart is healthy and in perfect working order. However it is important to understand how the heart works and to recognise signs and symptoms of heart disease (cardiomyopathy) and congestive heart failure.

Diagram of the anatomy of the heart

How the heart works

The heart functions as the physiological pump to the body. The heart is divided into left and right sides pumping deoxygenated from the body to the lungs  and oxygenated blood from the lungs to the body. The heart is further divided into upper atriums receiving blood and lower ventricles used for pumping. The divisions between the chambers are called valves which assist in the mechanical action of pumping blood and preventing blood in the atriums mixing with blood in the ventricles.

Heart Disease and congestive heart failure in pets

All tissues in the body require oxygen to function, therefore how an animal’s heart works is vital. Cardiomyopathy is the medical term for “disease of the heart muscle”; “dilated cardiomyopathy” is a disease in which the heart muscle is flabby and weak. Typically the heart is enlarged and not functioning optimally. The causes of cardiomyopathy generally are unknown, however certain dog breeds have a genetic predisposition. Over time the condition can deteriorate as the heart becomes overloaded and often leads to congestive heart failure (CHF).

Congestive heart failure (CHF) occurs when the pumping ability of the heart is deficient and results in an insufficient oxygen supply to the tissues. The precursors to heart failure in dogs is variable and in some cases dependent on the age, breed or size. Small breed dogs such as Pomeranians, Maltese and Poodles tend to develop CHF as a result of a leaking valve (usually the Mitral valve). Whereas larger breed dogs CHF is usually caused by Dilated Cardiomyopathy, as mentioned above.

In cats, cardiomyopathy (usually hypertrophic) and congestive heart failure is less common than in dogs, however is usually as a result of conditions such as high blood pressure, hyperthyroidism and other heart defects or abnormalities.

Signs & symptoms of heart disease or congestive heart failure

  • Prolonged spells of coughing
  • Difficulty breathing (shortness of breath, rapid breathing)
  • Weakness or lethargy (lack of energy)
  • Weight loss and loss of appetite
  • Fainting or collapsing
  • Abdominal swelling
  • Depression
  • Restlessness, especially at night


With the exception of severely affected animals, cardiomyopathy and congestive heart failure is treatable. Treatment is dependent  on your veterinarian’s diagnosis, what type of heart ailment is identified  and/or the stage of  the disease. Treatment usually includes prescription medication to optimise the heart’s functioning abilities and a diet change (lower in sodium).

In conclusion

When it comes to your pet’s health, visiting your veterinarian annually for a general health check up or biannually for dogs and cats over 7 years of age, is recommended. If you have noticed changes in your pets behaviour or general well being, rather visit your veterinarian. The earlier your pet is diagnosed, the more effective the treatment and monitoring of heart disease.



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s