Pets With Heart Disease

Many of the forms of heart disease in cats and dogs are progressive; however, with proper management and diet, your pet may be able to have a better quality of life.

NORMAL HEART AND CIRCULATION

The heart is the most important muscle in your pet's body. It is the pump which drives blood containing nutrients and oxygen through the blood vessels to the cells of the body:

1. Air is inhaled into the lungs where oxygen is picked up by tiny blood vessels. The oxygen-rich blood is then carried to the left side of the heart by a large blood vessel.

2. The heart pumps the oxygen-rich blood through the arteries to the body's tissues, collecting absorbed nutrients from the intestinal tract.

3. The cells of the body remove the oxygen and nutrients from the blood. Waste products from the cells, such as carbon dioxide, are removed by the blood.

4. The de-oxygenated blood then returns to the right side of the heart from the body through the veins.

5. The right side of the heart pumps the de-oxygenated blood back to the lungs, where the carbon dioxide is removed, and more oxygen is picked up. The left and right sides of the heart are separate, so that the entire system is a circuit moving blood in one direction through the body. Most forms of heart failure involve a decrease in the pumping ability of the heart on one or both sides. This results in a build up of fluid causing fluid accumulation and congestion in the chest and/or in the abdomen.

HEART DISEASE IN DOGS

Heart disease in dogs is often caused by defects in the valves or the heart muscle (myocardium). Animals with heart failure may retain salt (sodium chloride) and water in their bodies leading to fluid retention. This fluid may accumulate in the lungs and in the abdomen, leading to coughing, difficulty in breathing, and abdominal distension. If the heart is not working as an efficient pump, the amount of blood circulating to the body will be decreased, causing fatigue, weakness, and a pale appearance of the gums.

Treatment for heart failure may include feeding a low sodium diet and restricted exercise, along with the use of one or more drugs. The drugs are used to increase the strength of contraction of the heart muscle, encourage water loss in the urine, and dilate the blood vessels so that the heart can more easily circulate the blood. With careful assessment of your pet's individual needs by your veterinary surgeon, and your commitment to management at home, your pet may be able to lead a relatively comfortable life.

HEART DISEASE IN CATS

In cats, heart muscle problems (cardiomyopathies) are the most common type of heart disease. One form of this disease is due to feeding a deficient diet; other forms of the disease include one due to excess thyroid hormone (hyperthyroidism), and those from unknown causes. Any of these diseases can lead to accumulation of fluid in the chest and breathing problems. Cats of any age can be affected with diseases of the heart muscle. Heart disease due to an underlying problem, such as hyperthyroidism may be corrected when the under lying problem is addressed. With proper management, some cats with a history of heart disease can lead a relatively normal life.

LOOKING AFTER PETS WITH HEART DISEASE

A low sodium diet may compliment drug therapy and help to minimise fluid retention and reduce coughing and discomfort.

It is important not to feed any snacks, treats or titbits unless advised by your veterinary surgeon, as these may contain a higher level of sodium than your pet requires.

If your pet is overweight, you may be advised to try a low calorie diet, as extra weight may increase stress on the heart and lungs. Animals with heart disease may have a decreased appetite from feeling unwell and as a side effect of heart drugs that are necessary for them. Special diets must not only benefit health, but must also taste good. Your veterinary surgeon will work with you to encourage your pet to eat an appropriate diet. Feed the prescribed diet as advised by your veterinary surgeon and only to the affected pet.

DRUG REGIMES IN THE TREATMENT OF HEART DISEASE

A number of different approaches are taken to the treatment of heart disease, depending on the individual situation. These include:

1. Diuretics. So-called "water tablets", and the commonest is FRUSEMIDE. These tablets increase fluid excretion, and help to disperse the retention of fluid associated with heart failure.

2. Cardiac Glycosides. These drugs act on the heart muscle directly. They slow the heart, improve the strength of its contractions, and overall improve the efficiency of its pumping action. The best known is DIGOXIN.

3. Vasodilators. These drugs are relatively new to the veterinary world. They have a complex action, opening up the circulation in the "periphery" of the body. This takes the strain off the heart, and in so doing, allows it to pump more effectively. These drugs include enalapril and benazepril.

4. Pimodendan is one of the latest cardiac drugs and improves cardiac output in the failing heart. Trials have shown it to be highly effective.

OFTEN these groups of drugs are used in combinations, and your vet will guide you as to the needs of your pet. Do follow carefully the instructions you are given.