Caring for Pets with Heart Disease

By Dr Joanna De Klerk

Heart disease is not often curable, but the good news is that it can be managed extremely well. So, if your four-legged friend has just been diagnosed with a heart condition, try not to despair. There are excellent medications and lifestyle changes you can implement into your furbaby’s life, which will extend his quality of life with very little effort. Before you know it, it will simply be a habit and your beloved pet will live a happy life.

What is Heart Disease?

Heart disease in itself is an overarching name for many different conditions of the heart. The heart is an essential organ which is made up of a strong muscle. It contracts to pump blood to the lungs and then to the body, to deliver oxygen and nutrients for the body’s cells in order for them to work.

Within the heart there are several valves which ensures the blood keeps moving forwards. If your pet has recently been diagnosed with heart disease, you might have heard your vet say he has a heart murmur. Murmurs are when there is a turbulent flow of blood in the heart, which frequently is caused by faulty valves or narrowing of parts of the heart.

There are six different grades of murmur, from Grade I to Grade VI. Grade I is the quietest, and is often difficult to hear, even with a stethoscope. Whereas Grade VI is extremely loud and can often be heard with your ear if you place it against your furchild’s chest. For most heart conditions (there are some exceptions), the severity of the heart disease is linked with the severity of a murmur, and even some Grade I murmurs are simply due to stress, rather than a clinical condition.

When there is a disrupted flow of blood, the muscle of the heart has to contract much harder to pump out the same amount of blood as usual. This means the muscle gets thicker, giving the appearance of the heart becoming larger, but often just on the affected side of the heart.

For a while, the heart can cope, but eventually the blood will begin to back up due to a slower process of blood flowing through the heart. Therefore, there is a greater pressure inside the veins than usual, and as a result, excess fluid is pushed out of the veins into the lungs or abdomen.

Due to this progressive process, heart disease typically presents as lethargy, due to decreased oxygen to the cells, coughing, due to an increased heart size pushing on the lungs and bronchi, and fluid build-up in the lungs and abdomen, resulting in difficulty breathing and a pot-bellied appearance. Eventually, heart disease can lead to fainting and death. However, there are excellent medications which can help your furbaby deal with the extra load on his heart, extending the amount of time your four-legged friend has a quality, happy life.

The Differences Between Cats and Dogs

Dogs and cats don’t tend to get the same heart conditions; however, the same drugs and same lifestyle management changes are often recommended.

Your pup is more likely to have something wrong with a structural component of the heart, such as a valve or outflow tract. Whereas your kitty is more likely to have something wrong with the musculature of the heart, resulting in an inability to pump effectively.

Sometimes in cats, an underlying condition is to blame, such as hyperthyroidism. So, it is important to investigate if that’s the case and get that under control too.

Diet and lifestyle can also have a strong influence on the health of the heart and likelihood for heart disease to develop. But more often than not, it’s down to genetics (especially linked to many dog breeds) and a bit of bad luck.

Monitoring Your Pet with Heart Disease

Your pet’s heart disease needs to be closely monitored to ensure that it is not progressing, and your beloved friend isn’t beginning to show clinical symptoms. So, it is important to regularly visit your vet. Check-ups every three to six months will pick up on any changes since the last time you were there. Your vet might perform the following tests:

  • Listening with a stethoscope to assess if the heart rate or heart murmur has worsened.
  • Ultrasound scan to check the structure of the heart.
  • Blood pressure test to check the peripheral blood pressure.
  • Blood test to check parameters such as proBNP (which indicates heart muscle damage) and sodium (which is commonly retained in heart disease).

At home, you can also keep an eye on your pet’s condition to ensure they are still coping well. You should check the following things at least once a week:

  • General demeanour: Has your furbaby started slowing down? Been reluctant to go for their walk? Or become less interested in playing with their toys?
  • Respiratory rate: How fast is your pet breathing? Without disturbing him, count how many times he breathes in 15 seconds, then multiply it by four to get a breaths per minute reading. This should be under 30 breaths per minute at rest.
  • Heart rate: How fast is your pet’s heart beating? Place your hand just behind your dog’s left elbow, or on the chest of your cat, and count how many times the heart beats in 15 seconds. Like the breaths, multiply it by four to get a beats per minute calculation. You can also ask your vet where to feel for the femoral pulse on the inside of the back leg. The beats per minute measurement will vary depending on the size of your dog, so you should ask your veterinarian what a normal rate would be for your dog.

Medications for Heart Disease

There are several different classes of drugs which your veterinarian might use to manage your furry friend’s heart disease. It is often the case that your vet will prescribe one or two to start with and add in more when your pet is no longer coping.

Diuretic medications, also known as ‘water tablets’, increase the amount of fluid that your pet will urinate out. This helps to get rid of fluid build-up in the lungs and abdomen.

Cardiac glycosides are an excellent drug to improve the pumping ability of the heart. They improve the strength of the contractions, ensuring the maximum amount of blood is pumped out with each beat.

Finally vasodilators, also known as ACE-inhibitors, are complicated medications. However, their overall aim is to reduce the pressure in the veins away from the heart, reducing fluid being pushed out into the body, and decreasing the strain on the heart.

Some drugs will need to be administered once a day, others two or three times. And when you have several to administer, it can get confusing. So, it is a good idea to write out a chart with timings, which you can tick when you’ve given your dog the medication. A pill box can also be helpful to organise which pills to give when.

Most heart medications come in the form of pills, although occasionally you might be given a liquid. For some pets, putting the pill in the food is an easy way of getting it in, however, many pets (especially cats) get wise to it. You should never crush a pill to mix it in food without the go ahead from your vet, as some pills are enterically coated, meaning they have a special protective layer on them to ensure they reach the intestines without being damaged by the stomach acid. If you struggle to get pills in your furbaby, ask your vet how to effectively use a ‘pill popper’, which is a device that makes putting the pill in your pet’s mouth much easier (and often saves your fingers too!).

Nutrition for Heart Disease

There are prescription diets on the market which your vet can advise you one, that will help manage your pet’s heart disease.

A diet low in salt (sodium chloride) is really important, as salt and water are often retained with heart disease, and that’s the exact opposite of what heart medications are trying to achieve!

Many supermarket foods are extremely high in salt, which might push you towards trying to make a homemade meal. However it is difficult to balance a homemade meal, so it is better to buy a commercial food. Be aware that many titbits are also high in salt, such as cheese and processed meats.

A salt restricted diet should be between 0.2-0.25% sodium on a dry matter basis for dogs, and about 0.25-0.33% on a dry matter basis for cats.

Drinking water can also contain sodium, and is hard to control, so rather than giving your heart patient tap water, you should also consider changing to distilled or low sodium bottled water.


As heart disease advances, your furry friend will begin to struggle more with exercise. However, moderate exercise will help keep the heart healthy, so it shouldn’t be avoided.

With the go ahead from your vet, encourage your beloved pet to be active in a way which doesn’t cause excessive panting, weakness or shortness of breath.

It is also excellent for your furchild’s mental health, especially when they are feeling low.

Take Home Message

While heart disease is a serious condition, it can be relatively well managed with the help of your vet, medications and some simple lifestyle changes for your beloved pet. The sooner you implement all these things, the better the outcome, and in many cases your four-legged friend can go on to have a happy, healthy, normal life.

Caring For Pets With Heart Disease