Matters of the Heart

Today is a day to wear red to promote heart health awareness for women.

So, in honor of that, besides wearing red today at work, I thought I’d touch on cardiac issues in pets.

This will NOT be an exhaustive look at everything we see in dogs and cats. I just wanted to make people aware of something that they may not have thought about before.

There are a variety of heart issues that dogs and cats can have. Not surprisingly, they are quite a bit different. Some animals have congenital heart issues (they are born with the problem) or they develop them later on in life (acquired heart disease). 

As part of any exam, your vet should listen to your pet’s heart. This includes each puppy or kitten visit and any other annual or sick visits. We listen for rate, rhythm, and if there is a murmur present. A murmur happens because there is abnormal blood flow in the heart. An abnormal rhythm indicates a problem with the electrical control system that coordinates the heart chambers pumping in the appropriate way.There can also be issues with an abnormally low (bradycardia) or high (tachycardia) heart rate. 

The best way to further evaluate an murmur or  is with a cardiac ultrasound. For an abnormal rhythm or rate issue we prefer an electrocardiogram (EKG). 

In the growing animal, sometimes we find a murmur that either gets louder or goes away as the animal grows. The ones that go away represent pathways that directed blood flow while the animal was in utero and have taken a little longer to close down after birth. The ones that get worse are those that usually represent congenital issues.  Some of these can be surgically repaired, while others are something that the dog or cat either lives with (such as a ventral septal defect - a hole between the right and left ventricles) or some may respond to medication.

Acquired diseases are somewhat breed depending and include issues with the valves between the chambers and the heart muscle itself. 

Cats generally have one major type of disease we call cardiomyopathy (heart muscle disease). There are subgroups of this and I’ll expound on those next week.

I have often picked up these issues on an annual exam where the owner is not reporting any problems. But what things should you be on the look out for that could indicate a cardiac issue? 

-coughing

-exercise intolerance 

-breathing difficulty - increases rate or effort of respirations

-decrease in appetite

-seizure like episodes which are actually syncope or passing out from lack of proper blood flow/oxygen to tissues

There are other signs that are less common and would show up in more severe cases like a dog who’s belly seems to be getting larger (caused by right sided heart failure and fluid build up in the abdominal cavity). 

Cats generally have either no signs or often will vomit (vs coughing). Unfortunately sudden death can occur in these guys. And that can be the only "sign" - if you can really call it that.  

I just want to say that it can be difficult to determine what caused a sudden death in an animal, when there are no apparent external injuries or history that helps us. We can do a necrospy (the proper term for a post-mortem in an animal) but with cardiac issues, it can be hard to see without sending some tissue out to the pathologist. Even then, they cannot determine that there was an issue with the electrical conduction system or always see a small blot clot that could've caused the issue.

Next week, I'll get into some specifics on cardiac issues in our pets.