The dog looked obviously in discomfort, with his tongue hanging out, panting for breath. After a thorough examination, I told the owner, “Your dog has a heart problem.” Oh!, she said, sounding surprised, “You mean dogs have a heart?” I am not exaggerating, this is true and it happened 18 years ago, at a time when I had gone against convention to study cardiology in dogs. Ok, so maybe this particular client didn’t exactly have a brilliant IQ, but understanding of heart diseases in pets was at an astonishing low in those days. Things have changed now, and poeple don’t seem surprised when an ECG is suggested as part of a preoperative workup or when cardiac diseases are diagnosed in their pets.
Heart disease in dogs
One common question I encounter is do dogs get heart attacks? Heart attacks or myocardial infarcts are extremely rare in dogs. However, there are other heart diseases which are prevalent, depending on the breed, age and sex. The larger breeds commonly suffer from a condition affecting the heart muscle called ‘dilated cardiomyopathy’. In this condition, the heart muscles get progressively weaker till the pumping action of the heart is hampered, causing a build up or congestion of blood in the lungs or abdomen. This condition ultimately leads to congestive heart failure and is generally seen in dogs above 4 years of age. In some breeds, this problem could be due to deficiency of carnitine, which is an amino acid found in meat. So, vegetarian dogs have a higher chance of being affected. In some dogs, the uptake of carnitine by the cardiac muscle is reduced, and they can be supplemented with carnitine powder in their diet. Special cardiac diets are available which incorporate all the ingredients needed for a dog with heart disease. The other common entity is called ‘valvular heart disease’. This is commonly seen in smaller breeds. Since this is an age related condition, it is most commonly seen in dogs over 7-years of age. In this condition, the heart valves undergo an age-related deterioration.
The valve leaflets curl up with age, so that when the heart pumps blood, part of it flows backward through the defective valve. The end result is the same- fluid gets built up in the lungs, ultimately causing heart failure.
Signs of heart disease
Unfortunately, symptoms of heart disease in dogs are insidious. The dogs slows down and gets tired after exercise or exertion. The owner often mistakes this for signs of normal ageing, or thinks that the pet is lazy and needs to be exercised more. This is followed by coughing, which is seen after excitement or exertion or at nights. The cardiac cough is a dry cough, and owners describe it as ‘the dog trying to clear his throat’. Breathlessness is seen for a prolonged period after exercise, and in advanced stages, even at rest. Sometimes the abdomen gets bloated due to filling up of fluid (called ascites). Swelling of lower legs (called oedema) may also be seen. If there are rhythm disturbances, the dog may have episodes of fainting. In chronic, advanced cases, there is weight loss. It is therefore very important for the owner to have a high index of suspicion. If these diseases are detected early, they can be managed better. Also the incidence of heart disease is very high- 70% of dogs above 7 years have heart problems.
An yearly cardiac examination for dogs over 7 years, which includes a physical examination, X-rays and electrocardiogram is advised. If signs of heart disease are noticed, contact your vet. If heart disease is diagnosed, diet modification, along with certain medications will be started. These will have to be continued throughout your pet’s life, with modifications done whenever necessary. So remember, timely intervention is the key to an early diagnosis of heart disease.
(Dr. Sangeeta Vengsarkar Shah (Ph : 24461748) has a specialisation in cardiology.)