Heart disease in our pets – Part 2: Cardiomyopathy

Cardiomyopathy is a big issue in the pet world too. In dogs we most often see dilated cardiomyopathy or DCM where the heart muscle becomes weak, thin and ineffective. In cats we generally see hypertrophic cardiomyopathy or HCM where the heart walls get very thick and there’s not much space left in the heart for the vital blood.

We’re going to talk about these conditions separately.

DCM in dogs – he’s feeling tired
Often the first sign of DCM in dogs is that they start to struggle with their walks. The lively doberman who would run rings around you is now puffing and panting and lagging behind. Unlike small dogs with heart disease, a cough is often not the first sign.

Cardiomyopathy is a condition of large breed dogs although sometimes we see it in Cocker Spaniels. There’s not really anything you can do to stop your dog getting the problem – it’s just one of those things which happens to some unlucky families.

Veterinary assessment
When we check out a dog with DCM we will often hear an irregular heartbeat and there might also be a murmur. Blood tests, chest x-rays, an electrocardiogram (ECG) and a heart ultrasound scan (echocardiogram) will tell us exactly what is going on.

In most cases, the disease makes the heart muscle thin and weak and it can’t pump blood around the body as well as it needs to. This in turn means the body is short of oxygen and exercise is difficult. As the heart’s condition gets worse, fluid builds up in the lungs and belly and the dog starts to feel very tired and may even faint.

Can you treat DCM?
In many cases we use diuretics to dry out the lungs and other specialised drugs to reduce the strain on the heart and slow down the progression of the disease. Exercise management is very important to help your dog cope with the problem. Treatment can often help your dog have a good few months of extra life – but sadly we often find DCM progresses quickly despite treatment.

Cardiomyopathy in cats – I can hear a murmur
Because we walk our dogs we notice when they start to slow down. But with cats it’s tricky – most of them laze around all day anyway – so how do you know if they are feeling tired and lethargic due to heart problems?

The early symptoms of heart disease in cats are most often picked up at a pet’s annual health check. We generally hear a murmur or an abnormal rhythm (often a “gallop” rhythm, ie. it sounds like a horse galloping!) which alerts us to the problem. As with most diseases early intervention helps us to get a better outcome and annual health checks are a very important screening process. If we catch the disease later in the process, it is often due to some laboured breathing that the owner finds, especially just when resting.

In cats there is often an underlying cause to the heart problem, like an overactive thyroid (hyperthyroidism) or high blood pressure, though the heart disease can be a primary problem of its own. A full clinical examination will give us more information and blood tests, xrays and ultrasound scans will give us a full picture of what’s going on.

The most important part of treatment is to deal with the underlying cause of the heart disease, as well as using tablets to reduce the load on the heart.

We find cats often respond really well to treatment with many years of good health following diagnosis, especially if caught early. The hardest part can be getting them to take their medication! But that’s another blog for another day…