Listed below are several of the more prevalent cardiac diseases of dogs. This is article is intended to be used as a summary of some of the common cardiac diseases. The article was not written by a cardiologist and is for general knowledge only. Please consult with your veterinarian for any cardiac conditions diagnosed.

The heart is a muscular organ consisting of four chambers- a right and left atrium and right and left ventricles. Valves are located between the atrium ,ventricles, and the two major vessels leading to the heart to prevent blood from flowing abnormally. Blood is circulated through the body by the pumping action of the heart. Deviations in the size of the chambers, or strength or elasticity of the muscle, or disease of the valves, will affect the flow of blood in the body and subsequently the dynamics of all the organs in the body. Once the heart begins to malfunction a vicious cycle develops and abnormal fluid build-up begins in different areas of the body depending on which side and part of the heart are involved. Thus, congestive heart failure develops.

Cardiomyopathy in dogs

Dilated cardiomyopathy:

This is a flaccidity of the heart muscle similar to cats. The heart cannot pump properly causing congestive heart failure. There is a suspicion that this may be a genetic disease. We see a breed predilection in the Doberman pincher, boxer, giant breeds i.e. Irish wolf hound, Scottish deer hound, great dane. We also see a taurine related dilated cardiomyopathy in cocker spaniels.

Clinical signs are difficulty breathing, weakness, coughing, weight loss, abdominal distension, fainting, and sudden death.

Exam findings include decreased pulses, abnormal heart sounds and beats, muffled heart sounds, murmurs.

Diagnosis is based upon x-ray and ultrasound.

Treatment for congestive heart failure include treating with ACE inhibitors, such as enalapril, digoxin, and the diuretic furosamide and low salt diets. Evidence suggests that the nutriceutical supplements taurine and carnatine as well as Co enzyme Q 10 may be of help.

The prognosis is poor.

In our practice we recommend that all American cocker spaniels be placed on taurine as puppies and continued for life.

Hypertrophic cardiomyopathy of dogs:

This is a rare disease of dogs caused by a thickening of the heart musculature. Due to the thickening of the heart muscle, the size of the heart chamber is smaller resulting in decreased ability of the heart to pump blood to the rest of the body.

This disease has been described in dogs of all ages.

Signs range from asymptomatic to those of congestive heart failure, including heart murmur, difficulty breathing, coughing, and exercise intolerance

Diagnosis is best made with x-ray and ultrasound

Treatment includes rest, low salt diets, diuretics such as furosamide, beta blockers such as atenalol or propanolol or calcium channel blockers such as diltiziam. People with hypertrophic cardiomyopathy improved symptomatically when given verapmil on a long term basis. Low salt diets may be recommended.

The prognosis is poor.