Ty is an older dog who showed up in our office with a cough shortly after being at a kennel. Our first thought was that she had acquired a respiratory infection common after exposure to other dogs. When her cough persisted, we were convinced it was far more serious. She had a slight heart murmur, but the owner was not aware of any other symptoms of heart disease.
The normal procedure for a dog with suspected heart disease is to take radiographs and an electrocardiogram looking for heart enlargement. Some dogs and cats require an ultrasound exam to further investigate their heart function.
Ty has mitral valve disease, also called degenerative valve disease. She is still alive years after her disease was diagnosed and doing as well as she can for her age on medication.
As the heart fails, pulmonary edema, or fluid in the lungs, can cause a cough. In addition, the enlarged heart pushes on the airway called the main stem bronchus. One of the first drugs we use is Lasix (furosamide). This is a diuretic that helps remove excess fluid from the lung. Enacard (enalapril) helps to lessen the load on the heart, and a remarkable new drug called Vetmedin has helped many a dog with a failing heart improve and dramatically lengthen their lifespan.
Vetmedin (pimobendan) strengthens the contraction of the heart. Although not as useful in humans, it is literally a life-saver for many dogs with heart failure due to mitral valve insufficiency.
Silky was another patient with similar classic signs of heart disease. After three years of treatment, we recently saw him for his twice-a-year senior checkup. Even with advancing years and chronic end-stage heart disease, he was doing so well that he was difficult to restrain. I could hardly do a proper exam beyond listening to his heart.
Silky's owner is happy with the comfort of an extended time with her pet. As a veterinarian with years of experience, even I was surprised at how well my patient was doing for such a long time with chronic heart failure.
In addition to a cough, other signs of heart failure include a decrease in exercise tolerance, an increase in the respiration rate, and a distended abdomen with weight and muscle loss. Owners may also notice fainting, restlessness and lack of appetite. Murmurs detected at a routine veterinary exam and heard on examination of the heart should alert owners. Not all murmurs are significant, however, and in some young puppies murmurs can disappear. Older dogs may have a murmur without symptoms for years.
Some breeds of dogs are very prone to heart disease. In addition to the Cavalier King Charles spaniel, which commonly develops mitral valve disease, others include miniature poodles, cocker spaniels, miniature schnauzers and dachshunds. Smaller dogs are more prone to degenerative valve disease, which accounts for 75 percent or more of the heart problems that we see in dogs.
Although dogs and cats can have a number of heart issues, they differ from humans in a number of ways. Heart attacks and strokes that are common in people are actually rare in dogs. Blood pressure elevation, seen in a high percentage of older people, is not common in pets.
Dental disease can be a contributing factor in animal heart disease. Bacteria in the mouth can spread by the bloodstream and affect other organs, including heart valves. Keeping a clean mouth with routine teeth cleaning has many benefits in the older patient.
Part of every comprehensive health exam is an auscultation of the heart. We listen for arrhythmias and murmurs. If chronic valve disease is detected early and medications are used properly, dogs can have months and even years of additional quality of life.
Walking dogs is one of the best ways to ensure an owner's cardiovascular fitness. It is important to not ignore the signs of heart disease in our pets as well.
Lawrence Gerson is a veterinarian and founder of the Point Breeze Veterinary Clinic. His biweekly column is intended to educate pet owners. Consultation with a veterinarian is necessary to diagnose and treat individual pets. If you have a question you'd like addressed in Pet Points, email email@example.com. Please include your name and municipality or neighborhood. First Published April 7, 2012 12:00 AM