About 10% of all dogs have heart disease. Most importantly, the incidence of heart disease increases dramatically with age with 30-35% of dogs aged 13 and over affected.
Heart disease (or congestive heart failure) is an unfortunate but tolerable condition for your dog. Although treatments cannot reverse heart disease, your dog can live a relatively normal life. Aging is the most common reason dogs develop heart conditions, but other factors like heartworms can also lead to heart disease.
Heart disease typically causes the heart to enlarge, and this enlargement causes a loss of efficiency. The heart then begins to hold more fluid than it should and this is where the real problems begin. For this reason, veterinarians recommend feeding dogs a low-sodium food that will help reduce fluid build-up and make it easier for their hearts to work effectively.
THE VARIOUS FORMS OF HEART DISEASE
While dogs of any size and age may develop heart failure, the type of heart disease a dog contracts often depends on its breed/size. There are two main categories of canine heart disease — congenital and acquired.
#1. Congenital Heart Diseases are problems a dog is born with, such as a hole in the wall between heart chambers (known as a ventricular septal defect). These diseases are rare and tend to be very severe, limiting the dog’s lifespan.
#2. Acquired Heart Diseases are more common (around 95% of cases) and develop over time. They are frequently associated with aging or physical injury to the heart from trauma (such as getting hit by a car) or certain infections (like heartworm disease).
The location of the problem and the specific tissues involved determine the type of acquired heart disease.
The location of the problem and the specific tissues involved determine the type of acquired heart disease.
- Valvular disease occurs when the valves between heart chambers leak. This leads to abnormal blood flow in the heart and can result in hypertension and fluid collection outside the blood vessels, commonly in the lungs and belly. The most frequently involved valve is the mitral valve. Older small breed dogs, such as Chihuahuas, miniature and toy Poodles, Pomeranians and miniature Schnauzers, are predisposed to this condition.
- Myocardial disease involves the heart muscle. It can occur if the heart muscle becomes too thick (hypertrophic), too thin and stretched (dilated), or has been damaged from injury or infection.
- Arrhythmia is a general term describing abnormal electrical signals in the heart that cause individual cells in the muscle tissue to contract at different times or at an incorrect rate. This can lead to a heartbeat that’s too fast or too slow, or to a lack of coordination between the different parts of the heart. In any of these situations, the heart is unable to pump blood effectively.
WHAT ARE THE SIGNS TO WATCH OUT FOR?
If your dog exhibits the following symptoms, take him to your veterinarian for an accurate diagnosis:
- A low-pitched cough that sometimes leads to gagging. Coughing is a very common symptom of many illnesses, one of those being heart disease. Minor coughs will not last more than a few days. If after three days your dog is still coughing, or is experiencing other symptoms, seek veterinary care.
- Breathing difficulties including shortness of breath, laboured breathing or rapid breathing.
- Reduced ability to exercise
- Loss of appetite is almost always a symptom of something. If combined with any of the other symptoms, it could be a strong indicator of heart disease.
- Noticeable weight loss is definitely a symptom of heart disease, though weight gain can be as well.
- More likely than weight gain is a bloated or distended abdomen, giving your dog a potbellied appearance.
- If your dog faints or collapses at any time, seek veterinary help. It may be a sign of many different serious illnesses, heart disease being one of them.
- If you notice behaviour changes in your dog, such as being less playful, reluctance to exercise, reluctance to accept affection, being withdrawn, or an appearance of depression, these are all signs of heart disease.
HOW IS HEART DISEASE DIAGNOSED?
These symptoms are common in other diseases, so it is important for your veterinarian to check for heart disease using some of the following methods:
- A Stethoscope exam can reveal murmurs and fluid in the lungs
- Palpation can reveal unusual pulses
- Chest X-rays reveal heart enlargement
- An ECG. This test measures electrical signals from your dog's heart and tells how fast it's beating and if that rhythm is healthy.
- An Ultrasound. Ultrasound uses sound waves to look at the size, shape, and movement of the heart.
- Blood and urine tests can reveal heartworms and the condition of other internal organs.
CAN DOGS HAVE HEART ATTACKS?
In humans a "heart attack" usually refers to myocardial infarction (MI). Myocardial infarction refers to death of the cells in an area of the heart muscle or myocardium. Cell death is usually due to oxygen deprivation caused by obstruction of the coronary blood vessels that supply blood to the heart muscles. "Heart attacks" are rare in dogs but unexpected and sudden death in dogs diagnosed with any form of heart disease is possible.
POSSIBLE TREATMENT OPTIONS FOR HEART DISEASE
While there is no specific research on how to prevent heart disease in dogs, there is some evidence that reducing inflammation can improve heart function. The best recommendation is to give your dog a lifestyle that does not encourage inflammation in the body. Do not allow him to get overweight and give him plenty of exercise. Good dental hygiene and a diet rich in antioxidants will also help keep systemic inflammation to a minimum, so brush your dog’s teeth and feed him plenty of fruits and vegetables along with whole high quality meat.
Although there is no cure for the common causes of heart failure in dogs, there are treatments available that can greatly improve and extend your dog’s life. If your dog has been diagnosed with heart failure and clinical signs are visible, it is likely that your vet will recommend a treatment programme. Your dog's treatment depends on what specific heart problem he has and what may be causing it.
Your vet may recommend one or more of the following:
- Medications to help the heart work and correct irregular heartbeats
- Medications to slow fluid build-up in the lungs
- Surgery to correct a torn valve or to insert a pacemaker to correct the heart beat
- A commercial or prescription low-salt diet to help decrease fluid build-up in your dog's body
- Limited activity or exercise to manage weight without putting too much strain on your dog's heart
Medication can also clear heartworms or bacterial infections if they're caught early enough.
This app allows you to count and record resting respiratory rate for a number of different pets and then facilitates the transfer of this information to your vet. You may also elect to post your results on Facebook or Twitter.