Lots of dogs are walking around right now, or playing in their backyards, or snuggled up comfortably on the couch with their owners, with heart disease. That’s because having heart disease alone doesn’t always mean that the dog is having problems related to the disease. The heart and the body do their best to compensate for the problems, until they can’t. And when that happens, the patient is in heart failure.
Routine wellness examinations, which include listening to the heart and lungs with a stethoscope, are key to early detection of heart problems. But as owners we have a role to play as well, and that means being observant to the subtle changes that can indicate developing problems with the heart. Read on to learn what to watch out for in your dog.
Coughing, especially when lying down
Before we talk about coughing, let’s establish that there are several different kinds of acquired (meaning not present from birth) heart disease in dogs. The most common type is something called valvular degeneration, and it most commonly occurs in small breed dogs. It’s an age-related change, and it occurs when the heart valves get little nodules on them that prevent them from shutting tightly. Large breed dogs tend to get something called dilated cardiomyopathy, in which the heart gets very large as they age. Either kind can cause coughing.
Coughing in valvular disease comes on because as a response to the valve’s leakiness, the heart enlarges in one specific area. This causes the trachea to be pressed upwards, which causes coughing. Another reason coughing occurs with heart disease is that heart dysfunction can cause fluids to back up into the lungs.
The cough that occurs with heart disease is usually a dry, hacking, and sporadic cough. It’s often noticed more frequently at night, because lying down tends to complicate the conditions that lead to the cough.
Reduced tolerance to exercise
It’s important not to immediately chalk up a reduction in activity to “old age”, because it could most certainly be the sign of a medical problem.
Although lots of diseases can cause your previously playful and active dog to want to “sit this one out”, when the heart is malfunctioning it’s having a tough time pumping oxygenated blood out to the limbs. When oxygen levels go down, the dog gets tired faster – the same way you might feel if you regularly live at sea level and you take a trip to Colorado to go skiing.
Pale gums
One of the first things they teach you in freshman anatomy class in vet school is to “know what normal looks like”. The reason is that if you’re intimately familiar with what your dog is supposed to look like, you’re much more likely to recognize when something’s not right.
I always encourage owners to look at their dog’s gums and know how they look when the dog is normal and healthy. Take a picture if you have to – it helps for comparison should you become concerned that they’re not normal.
Simply stated, the heart is a pump. It’s designed to take a liquid (blood) and push it out through pipes (arteries and veins). When the pump is failing it’s very inefficient at pushing the volume of blood it needs to first into the lungs and then out to the body. The result is poor circulation of oxygenated blood, and one of the few places you can actually see this is in the gums.
Increased respiratory rate, especially at rest
Tough one, I’ll admit. Dogs pant, especially during or after play, and especially in the vet clinic. So how do you know the different a normal response to activity or stress, and a true problem?
Veterinary cardiologists tell us that measuring the sleeping respiratory rate of a dog is one of the most reliable indicators of respiratory distress due to heart disease. Dogs showing signs of heart failure will typically breathe more than 30 times per minute while sleeping. As an owner you can be proactive by counting your dog’s sleeping respiratory rate at home. Merely count one rise and fall of the chest as a single respiration, and count for 60 seconds. That’s his resting respiratory rate. It should be well under 30 breaths per minute.
Pot-bellied appearance
Abdominal distention, to the point where the dog looks somewhat pot-bellied, occurs only when the right side of the heart is failing.
This can happen with either valvular disease or dilated cardiomyopathy. The abdomen appears enlarged due to congestion (fluid buildup) in the liver and/or directly into the abdominal cavity. Usually the liver enlargement occurs first, and as heart failure worsens the fluid starts to collect in the abdominal cavity. In this case the abdomen not only looks large, but you can appreciate a “wave-effect” when you gently push on the side of it.
Restlessness
Another somewhat vague sign, but one worth noting. Because of fluid buildup and general discomfort, dogs with heart disease tend to have a hard time getting comfortable.
They may initially lie down only to find that the fluid that builds up in the body cavities is making breathing exceptionally difficult based on its position, so shifting to another position may improve things. You may notice that your dog attempts to get comfortable, then readjusts several times before settling.