Heart disease is one of the biggest killers of people, and while it is not such a significant problem in our pets, heart disease is still an important issue and can lead to very severe illness. People, dogs and cats tend to suffer from very different forms of heart disease, and that is important to understand before thinking about how we diagnose and treat these different conditions. Humans tend to suffer from heart disease caused primarily by the clogging of the arteries with fatty deposits linked to cholesterol, but this type of disease process, termed atherosclerosis , is very rare in pets. Instead of atherosclerosis, cats and dogs tend to suffer from 2 other main types of heart disease – valve disease, which is more common in dogs, and heart muscle disease which is the main problem with cats.
Heart disease is much less common in cats than it is in dogs, and the type of heart problem they suffer from is very different. Instead of leaking valves, cats tend to suffer from a problem called hypertrophic cardiomyopathy which is a bit of a mouthful but basically means ‘thickening of the heart muscle’. As this description suggests, this disease causes the wall of the heart to become thickened and this in turn restricts the ability of the heart to pump blood effectively. There are many contributing factors, but kidney disease and an overactive thyroid (hyperthyroidism) are probably the main risk factors as they both tend to increase the blood pressure and put extra strain on the heart.
Treating hypertrophic cardiomyopathy is not easy, but there are drugs such as B-blockers and calcium channel blockers that help. The outlook is not generally great, but if underlying health problems such as hyperthyroidism can be resolved, many cats can do reasonably well.
