By Heather Larson
Knowing what health issues your dog is susceptible to gives you the chance to catch a malady early when you have ample time to modify it. When the issue concerns the heart, you can slow down the disease before it progresses to heart failure, says Dr. Christopher Stauthammer, associate professor of veterinary cardiology at the College of Veterinary Medicine at the University of Minnesota in St. Paul. “Heightened awareness gives your dog a better quality of life, increased quantity of life, and minimizes the need for additional medication,” Stauthammer says.
The two types of inherited heart disease veterinarians see most often in dogs are degenerative mitral valve disease (DMVD) and dilated cardiomyopathy (DCM), clarifies Dr. Bill Tyrrell, a veterinary cardiologist in private practice at CVCA: Cardiac Care for Pets with locations in Maryland, Virginia, and Kentucky. DMVD affects small breeds more frequently, while larger breeds have more incidences of DCM.
If you own or plan to adopt one of the following breeds, you need to watch for symptoms they may exhibit that are common to heart disease. You should also take your dog for regular veterinary checkups, so a medical professional can also watch for clinical signs of changes in the heart.
The incidence of degenerative mitral valve disease (DMVD) occurs more frequently in this breed than any other. Fifty percent of Cavaliers develop a heart murmur, indicating onset of the disease, by age 5, and 100 percent by age 10, Tyrrell says. With DMVD, a leaky mitral valve causes blood to go backward into the left atrium of the heart. (Usually this valve closes when the heart contracts and the blood moves forward into the body.)
“Because the condition is inherited, we can’t do much to prevent it,” Tyrrell says. “Early symptoms of congestive heart failure include decreased exercise tolerance, labored breathing, and coughing. If you notice any of these, see your veterinarian right away. If your veterinarian detects a heart murmur, he may refer you to a veterinary cardiologist. Otherwise, schedule annual checkups with your general practice veterinarian until the dog reaches age 6 and then twice a year after that.” That way, the condition can be addressed before it becomes problematic, Tyrrell says.
Dachshunds often develop a leaky heart valve, or DMVD. Tyrrell says DMVD usually appears in this breed between 8 and 10 years of age. Regular annual veterinary checkups should reveal this condition early. As a Dachshund ages, you should increase those examinations to every six months, so the condition can be addressed before it becomes problematic.
DMVD can be controlled by medication, Tyrrell says. It also helps to keep the dog’s weight down so the heart doesn’t have to work harder than normal.
Degenerative mitral valve disease usually develops in middle age in these smaller breeds, Stauthammer says. “We see an even higher incidence in the elderly population,” he says. “The valve on the left side of the heart becomes structurally thickened, which makes the blood flow backward, causing a heart murmur.”
This enlarges the heart and triggers heart failure, Stauthammer says. Catching it early is the key so the disease can be treated with medications, a sodium-restricted diet, and fish oil supplements.
Dobermans are at risk for dilated cardiomyopathy (DCM), a disease of the heart muscle that causes the left ventricle to enlarge and cease functioning correctly. In the early or later phase of the disease, bad arrhythmias may develop that can be life threatening. As the disease progresses, an affected dog may faint, lose weight, exhibit shortness of breath, cough, or retain fluid that causes his belly to distend, Tyrrell says.
DCM occurs more frequently in male Dobermans, says Dr. Pamela Lee, assistant professor of cardiology at the Veterinary Teaching Hospital at Washington State University in Pullman, Washington.
If you know your Doberman’s family history and it includes incidences of DCM, tell your veterinarian so he or she can watch for symptoms, especially a heart murmur or abnormal heart rhythm. Tyrrell says annual exams should be ramped up to twice yearly when your dog reaches 4 years of age. Annual screening by a board certified cardiologist via electrocardiogram and echocardiogram should also be considered in all Dobermans, especially those with a family history of DCM, Tyrrell says.
Boxers are susceptible to arrhythmogenic right ventricular cardiomyopathy (ARVC). “ARVC is a genetic heart disease that results from fatty cells being deposited in the right ventricle muscle crowding out the normal cells. This can result in ventricular arrhythmias (life-threatening heart rhythm abnormality),” Tyrrell describes. “In early stages, dogs may display bad heart arrhythmias which affects their exercise ability and often results in fainting and, sadly, even sudden death.”
The most common congenital heart disease seen in Goldens is aortic stenosis. The aortic valve doesn’t form properly during gestation, and when the dog is born, the valve sticks. That makes the heart muscle thicken, Stauthammer says.
The narrowing of the valve can be mild, moderate, or severe. Most common in larger breeds, aortic stenosis may be apparent at birth if it’s in the moderate or severe stage. Milder cases usually appear in the dog’s first year. Ask your general practice veterinarian to listen for a heart murmur if you have a Golden puppy.
Another heart condition, sick sinus syndrome (SSS), affects this breed’s adult females the most. West Highland White Terriers and Cocker Spaniels are also prone to SSS. “The dog’s natural pacemaker doesn’t work and that causes fainting episodes,” Stauthammer explains.
Other symptoms of SSS include lethargy, exercise intolerance, irregular heartbeats (either fast or slow), or no visible symptoms at all, especially if the dog is already a couch potato.
Dogs who suffer from this condition often need to have an artificial pacemaker implanted. Nobody knows what causes this irregularity, but with yearly checkups, the dog should live a normal life, Stauthammer says.