Heart disease and related conditions, such as stroke, are significant contributors to human mortality. Around 10% of pets develop heart conditions. Rather than developing arterial plaques, which is the leading cause of acquired heart disease in humans, pets may be born with or acquire conditions impacting their heart structure or function, most often the heart valves or muscle, although many other disorders are possible. Our Smithtown Animal Hospital team explains the most common heart diseases affecting pets, ways to identify heart disease, and how we manage these conditions long-term.
Heart valve disease in dogs
The most common heart disease type in dogs affects the mitral valve, which controls blood flow from the left atrium to the left ventricle. Mitral valve disease causes the valve to thicken and prevents complete closure, allowing some blood to flow backward and get stuck in the left atrium rather than going out to the body. When the disease first begins, the backflow is minimal and doesn’t cause any problems, but the condition slowly progresses over time, typically years. Eventually, the backflow can cause the left atrium to enlarge, leading to heart failure.
Nearly all small-breed dogs and around one-third of large-breed dogs who acquire a heart condition are diagnosed with mitral valve disease. Most who develop the condition in older age do not progress to heart failure within their lifetime, but some breeds, including Cavalier King Charles spaniels and dachshunds, are predisposed to a fast-progressing version that strikes earlier in life.
Heart muscle disease in pets
Heart muscle diseases (i.e., cardiomyopathies) are the most common heart diseases in cats and large-breed dogs. Cats typically develop hypertrophic cardiomyopathy, which causes the heart to enlarge because of thickened, stiff muscles. Persian cats, Maine coons, and Ragdolls have a genetic risk for developing cardiomyopathy. Large-breed dogs, such as golden retrievers and Doberman pinschers, develop dilated cardiomyopathy, in which the heart enlarges, and the muscles become thin, flaccid, and weak. Boxers may develop a breed-specific cardiomyopathy that creates heart rhythm problems.
Cardiomyopathy generally has a worse prognosis than mitral valve disease, because the damage progresses more rapidly and eventually causes heart failure in many cases. Dogs and cats with cardiomyopathy are also at greater risk for serious blood clots, which can damage organs or cause death by blocking blood flow.
Congenital heart disease in pets
Congenital heart diseases are those pets have at birth. Congenital heart disease most often affects dogs and only rarely affects cats. Heart defects may include abnormal communication (i.e., holes) between heart chambers, misshapen valves, or narrowed blood vessels. Many of these diseases can be addressed and corrected surgically, allowing affected pets to live a normal life. Severe congenital defects may cause early death from heart failure if they cannot be surgically repaired.
Heart disease signs and diagnosis in pets
An abnormal heart sound (i.e., murmur) is typically the first cardiac problem sign. These murmurs may range from quiet and barely detectable to a loud and palpable rumble in a pet’s chest. Murmur intensity is often, but not always, related to disease severity, and the sound’s location may help a veterinarian narrow down a pet’s heart disease diagnosis. As the disease progresses and the heart enlarges and begins to fail, an affected pet may cough because their heart is pressing on their airway, or they may have difficulty breathing because of lung fluid buildup. Fluid can also accumulate in other body areas, including the limbs or abdomen. To make a definitive heart disease diagnosis, a veterinarian may have to take X-rays, perform an ultrasound examination, and conduct an electrocardiogram (EKG), completely analyzing an affected pet’s heart size and function.
Pet heart disease treatment and prevention
During your pet’s early heart disease stages, your veterinarian can usually manage your furry pal’s signs with medications that improve heart muscle strength, reduce blood vessel resistance, modify blood pressure, prevent arrhythmias and blood clots, reduce fluid buildup, and help the heart pump more efficiently. Some cardiac diseases require only one medication, while other conditions require several at one time. Heart conditions that progress to heart failure require intensive medical management, with multiple medications and frequent monitoring.
Most pets’ heart disease is not preventable. Providing a nutritionally complete diet and keeping a pet at a healthy weight may ameliorate some risk factors. Some recent U.S. Food and Drug Administration (FDA) reports indicate that certain grain-free, dry dog foods are linked to an increased risk for dilated cardiomyopathy. While the cause is still undetermined, we recommend that you avoid feeding your dog boutique pet food brands until more is known. To detect primary heart diseases and noncardiac diseases that may contribute to heart disease development, such as thyroid conditions, your veterinarian should routinely examine your pet’s health. If your veterinarian determines that your pet has a cardiac condition, they will initiate a treatment plan.
Pets who develop heart disease often live many years after their diagnosis, but their longevity hinges on diligent monitoring and consistent treatment. Our Smithtown Animal Hospital team can identify early heart disease signs more easily when a pet routinely has a wellness visit at least once per year. If your pet has a high risk for developing a cardiac condition, we will perform specific heart disease testing. To schedule your pet’s wellness care examination or to learn more about heart disease screening, diagnosis, treatment, or prognosis, give our team a call.