It is the week of Valentine’s Day! This means different things to different people. To some it means romantic dinners, to others (most of us) it means that delicious candy will soon be on sale. The one thing that everyone thinks about is hearts. Sure, we think about cute red and pink heart shapes, but sometimes, if you are in the right profession you think about actual beating hearts. What better time to talk about pet heart health? Since they shouldn’t partake in the candy, their gift can be increasing awareness of animal heart disease.
Our pets do not get “heart attacks” as people do, but many of them have heart disease that will ultimately be fatal. Pets can have heart disease for many years before owners even know. Our pets slowly compensate and are unable to let us know if they have mild chest pain or feel slightly weak when exercising. Heart disease develops in the pet not from diet, but from genetic factors and simple wear and tear. Though we would likely see some of the same problems in pets that people have if we didn’t control their diet, luckily, even our overweight pets get a fairly balanced diet. There has recently been a link between grain-free foods that have not undergone long-term trials and heart disease in dogs. Because this link is still being established, the best bet is to feed dogs food with some grains or that has undergone long-term feeding trials. Some pets are even born with heart disease. I’ll talk about the most common types in cats and dogs, and signs to look for that may help them be diagnosed sooner.
Chronic valvular disease
Many heart changes in dogs are detected first as heart murmurs, which is a good reason to have a yearly exam. The most common cause of heart failure in dogs is chronic valvular disease. The valves between the sections of the heart start to wear out. They start to thicken and change so that they no longer meet in the middle. This means that as the blood pumps through the heart, small jets of blood get through the valve gaps and whirlpool where it isn’t supposed to. Just like rocks will start to erode and change when water hits them continuously, the muscle starts to change where the blood hits it. Unlike a rock, the body responds and usually increases thickness instead of wearing down. This is especially common in small-breed pure-bred dogs, but can happen in any dog.
Dogs also get something called dilated cardiomyopathy. With this disease, the walls of the heart become thin and the heart distends so it is larger than normal. This means that every time the heart pumps, it pumps very weakly and the blood doesn’t circulate well. We then see a shortage of oxygen to the brain and a backup of fluid in the lungs. This can present as exercise intolerance, coughing, or a distended abdomen. This is seen more commonly in large-breed dogs and usually happens over time, though Great Danes and Dobermans are more likely to have this as a congenital (born with it) problem.
This is the disease that is being linked to grain-free food. The thinking is that the things which are added in the place of grains (dogs still need carbohydrates from somewhere) interfere with the absorption of a certain amino acid which is important for heart muscle integrity. Hopefully, as studies progress, we will have a clearer idea of this link. At this point, even supplementing the amino acid (taurine) doesn’t seem to help, since absorption is affected. Dogs taken off these diets often can reverse the disease more drastically than the type that is caused by time or genetics.
We all know how different dogs and cats are and how they like opposite things. In that train of thought, cats get an opposite type of cardiomyopathy called hypertrophic cardiomyopathy. This means that instead of the heart walls becoming thin, they become very thick. This leaves less space inside the heart for blood, and the heart walls do not contract effectively. This type of heart failure can be related to hyperthyroidism. Unlike heart changes in dogs, this is not heard as easily with a stethoscope in most cases. Because of the way the heart beats, cats with HCM are more likely to develop clots which travel throughout their bodies. These can cause problems in the lungs, brain, abdominal organs or often cause hind limb paralysis.
Sometimes this disease presents as cats just not doing as well, sometimes with episodes of “panting.” Some of these cats will have murmurs we can hear, and some we discover with increased heart rates. Unfortunately, some of these cats show no signs until they do throw a clot and become critically impaired. As with all things cat, any behavior changes can be an alert to underlying issues, so it is important to get them checked out.
Heart disease can result in many different signs. The underlying causes may be different, but most heart disease starts as subtle changes. Animals can become weak, develop a cough, be less tolerant of exercise, and even collapse or “pass out” for a moment. You may also see a bloated abdomen (over a few days, heart failure is not likely the cause of a big belly if your pet gets many treats a day). Since the heart also pumps blood to the lungs to become oxygenated before sending it to the body, fluid can build up in the lungs from ineffective pumping. Signs of this include coughing, panting and struggling to catch their breath after simple activity.
If a murmur is heard in a pet, usually the next step is to take chest x-rays. It is ideal to get a cardiac ultrasound (or echo) on them. This lets us see the thickness of the heart walls at every point, the function of the valves, and how the blood flows through the different parts of the heart. In this manner, we can more easily pinpoint the exact area of compromise and treat accordingly.
All types of heart failure can be treated with varying success. The earlier they are detected, the better chance there is of helping to prolong an animal’s life. There are medicines that help the heart beat faster, slower or stronger. There are also medications that help regulate blood pressure changes and fluid changes that might be associated with heart failure.
The main thing to remember is that changes in activity levels and coughing can be significant. If you have noticed a drastic change in activity overall or been putting off a yearly exam, it might be time to have a checkup. Once heart failure is detected, it is up to us to provide the best quality of life we can. This means keeping pets at a good weight, a good-quality diet and reduced sodium (in treats, softened water, etc.) Your veterinarian can help direct you once an issue is detected.
Our pets are our most loving Valentines, and they don’t need a special day to show us their love. Because of this unconditional love, it becomes our job to protect their hearts.