Symptoms of Heart Disease in Dogs and Cats Heart Disease Symptoms to Watch Out For

BY | October 11 | COMMENTS PUBLISHED BY
Symptoms of Heart Disease in Dogs and Cats
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Heart disease can manifest in these symptoms, or even be asymptomatic. Learn what heart disease symptoms you and your vet can look for.

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Heart disease in cats and dogs can be difficult to identify before heart failure, because it may in fact be asymptomatic, or without any symptoms. This can be problematic if the heart disease is progressing quickly and needs medical attention before heart failure becomes a likelihood. 

If your dog or cat is exhibiting any symptoms of heart disease, it is crucial that you seek veterinary attention. Your vet will be far more likely to identify signs of heart disease just by performing a simple physical examination.

Heart disease symptoms can be categorized into behavioral and physical symptoms.

Behavioral Symptoms of Heart Disease in Dogs and Cats

  • Lethargy is a common indicator of heart disease. When the heart becomes enlarged, it becomes inefficient, which can result in low energy and lethargy.

  • Depression may not be easy to identify, and heart disease may not be the first thing associated with depression, but dogs and cats with heart disease often suffer from it.

  • Decreased appetite may indicate that your dog or cat is feeling under the weather, and even if heart disease is not the first ailment associated with loss of appetite, itโ€™s a very good reason to get your dog or cat in to see a veterinarian for testing.

Physical Symptoms of Heart Disease in Dogs and Cats

  • Heart failure is the most serious symptom and the result of heart disease. In many cases, the dog or cat was not known to have heart disease until they experience heart failure.

  • Increased heart rate can be the result of an enlarged, inefficient heart, trying hard to keep up with the demands put on it by the body.

  • Coughing may be caused by blood overflow in the lungs, or in dogs, it can be caused by a persistent right aortic arch putting pressure on the esophagus.

  • Fluid in the lungs or abdomen occurs when one side of the heart begins to fail. Fluid can build up in the lungs when the left side of the heart fails to function properly, and will usually build up in the abdomen when the right side of the heart begins to fail.

  • Other common physical symptoms of heart disease are weight loss, general weakness, swelling and bloating of the stomach, bluish gums, vomiting, diarrhea, and constipation. These symptoms may be easily spotted at home.

Once youโ€™re at the vetโ€™s office, your vet may perform one or more tests.

Heart Disease Tests Explained

  • Physical Examination A physical exam is the first test your veterinarian can perform to get a sense of what further testing should be done. Your veterinarian will listen for a heart murmur and check for evidence of fluid in the lungs or abdominal cavity. In addition to the physical exam, a thorough history must be obtained, with information regarding activity levels and whether the animal coughs.

  • Chest X-Rays A chest x-ray is the logical next test after the physical exam because it allows the veterinarian to see inside the chest cavity without surgery. The x-ray can show the vet whether your cat or dog has an enlarged heart, and can show the vet the surrounding blood vessels. Fluid in the lungs and abdomen may also be clearly visible in an x-ray.

  • Echocardiography An echocardiogram is a test performed by a vet to determine problems with the blood flow within the heart. It can show the veterinarian where there are valve weaknesses and can show dimensions of the heart, and how well it pumps.

  • Electrocardiography An EKG can determine the rhythm of the heartbeat. It can determine whether your petโ€™s heart has an arrhythmia, which is an irregular heartbeat.
  • NT-proBNP Blood Testing ProBNP blood testing is an effective way for a veterinarian to pinpoint whether the symptoms are due to heart disease or respiratory disease. This test can even show an early predisposition to heart disease.
  • Blood Pressure Monitors A blood pressure monitor will indicate whether your dog or cat is at risk of a condition called hypertension, or high blood pressure.

Once all necessary tests have been performed, your vet will then determine the proper treatment. Some conditions such as congestive heart failure can be medically managed using medications such as Vetmedin tablets for dogs.

What Causes Heart Disease in Dogs and Cats

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Heart disease in dogs and cats is caused by either a genetic predisposition or a physical trigger, such as enzyme deficiencies or hyperthyroidism. Genetic heart disease is called congenital and non-genetic heart disease is called acquired heart disease.

There are some breeds of dogs that are very prone to heart diseases, such as Newfoundlands, Dobermans, and Great Danes. Some breeds, such as the Cavalier King Charles Spaniel, are genetically likely to develop a heart murmur, which leads to heart disease.

Causes of Congenital Heart Disease

  • Patent Ductus Arteriosis - Dogs Dogs are often diagnosed with patent ductus arteriosus (PDA) which occurs when the connecting blood vessel between the aorta and the pulmonary artery does not close properly after birth.

  • Aortic Stenosis - Dogs Large breed dogs are the most likely candidates for aortic stenosis, which is a narrow or partially blocked aorta.

  • Pulmonic Stenosis โ€“ Dogs Some dogs suffer from heart disease caused by pulmonic stenosis, which is a narrowing of the pulmonary artery. This artery carries blood to the lungs to be oxygenated, so this form of heart disease forces the heart to work harder to pump blood to the lungs.

  • Ventricular or Atrial Septal Defect โ€“ Dogs and Cats Your dog or catโ€™s heart (and yours) is separated into areas called ventricles and atria. A ventricular septal defect is a hole in the heart wall between the right and left ventricle of the heart, while an atrial septal defect is a hole between the left and right atria.

  • Persistent Right Aortic Arch - Dogs When puppies are born, they have an aortic arch which is supposed to deteriorate after birth, but if that arch does not go away, it can become wrapped around the esophagus.

  • Dysplasia โ€“ Cats Dysplasia is a malformation of the heart valves.

Causes of Acquired Heart Disease

  • Dietary Deficiency โ€“ Dogs and Cats Dogs and cats need a healthy balanced diet to keep their heart strong and efficient. If they do not get enough of the enzymes taurine and L-carnitine, the strength of the heart may diminish, resulting in cardiomyopathy (an enlarged heart) and heart disease. It is important to investigate your choice of pet food because if it is not providing your pet with enough taurine and carnitine, a supplement should be given.

  • Pericardial Disease โ€“ Dogs The pericardium is the sac that surrounds the heart, and when diseased, it can restrict the heart and prevent consistent strong heartbeats.

  • Heartworm Infection โ€“ Dogs and Cats If a dog or cat becomes infected with heartworm, and it goes untreated, it can lead to heart disease.

  • Endocarditis - Dogs The most common form of heart disease in dogs is a valvular problem called endocarditis, while in cats it is the least common. Endiocardiosis is usually found in older dogs because the valve has been working for so long it now fails to close and open all the way. This causes the valve to become leaky and allows some blood to leak back into the atrium or ventricle from which it came. This form of leak can do a lot of damage after a while. The heart becomes enlarged and can push up against the windpipe, causing a cough. The overflow of blood can also get pushed into the lungs. These leaky valves are also called heart murmurs, which are rated on a scale from one to six, with six being the most damaging.

  • Hypertrophic Cardiomyopathy โ€“ Cats When something happens that causes the heart to struggle to do its job, the heart can become enlarged, which is called cardiomyopathy. Hypertrophic cardiomyopathy occurs when the heart muscle thickens, resulting in abnormal heart function.

  • Dilated Cardiomyopathy - Dogs Dilated cardiomyopathy is a result of a taurine deficiency in the diet. This is no longer as common as it used to be due to increased taurine in most cat foods available today.

  • Restrictive Cardiomyopathy - Cats Restrictive cardiomyopathy results in stiffness in the ventricles of the heart, with a currently unknown cause.

  • Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) - Dogs and Cats Arrhythmogenic right ventricular cardiomyopathy is an arrhythmia, or an irregular heartbeat, in the right side of the heart.

  • Hyperthyroidism โ€“ Cats Hyperthyroidism causes the blood to have a high level of hormones, which is very hard on the heart, resulting in heart disease. It's often the cause of hypertrophic cardiomyopathy in cats.

The symptoms and treatments for heart disease may vary based on whatโ€™s causing the disease in your pet. For example, congestive heart failure can be managed with medications such as Vetmedin. However, dosage information is critical as some dogs may need a Vetmedin 5mg tab while others may need as low as 1.25 mg or as high as 10 mg. Always consult a vet before buying pet medication.

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis, or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.
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