Two days ago my barely 4-year old male cat developed a blood clot that lodged in his lower spine and, unfortunately after nearly 2 hours of extreme agony he went into full cardiac arrest and died at the veterinary hospital. He showed no symptoms of having heart disease prior to this episode. I am very concerned now about his male sibling, as I understand there may be a genetic component. Both kits were bottle-raised (street kittens whose mother was killed) and I know that there is a link between hypertrophic cardiomyopathy and soy-based vs. soy-free milk in mice and I wonder now if having been raised from 2 weeks old on the feline infant forumla rather than mother’s milk could have predisposed him to develop this disease. Would the best course of action be to have an ultrasound done on the heart of his surviving sibling in order to discover, and treat if so, if he also has this heart condition?

Thank you so much for taking the time to answer.

Yael

I am very sorry to hear of your loss.

Feline heart disease occurs when the muscle of the heart does not function properly. The heart muscle subsequently begins to grow (or hypertrophy), but this does not cause it to function better. The syndrome is known in medical circles as hypertrophic cardiomyopathy, or HCM.

HCM leads to abnormal blood flow through the heart. This can cause a blood clot to form in one of the heart’s chambers (the left atrium). The blood clot can in some instances break away from the left atrium and pass into the blood stream. Loose clots tend to lodge at the base of the rear legs. This situation, called an aortic thrombus (or saddle thrombus), compromises blood flow to one or both legs. Cats with blood clots in or near their legs suffer extreme pain and distress; the prognosis is very poor when this happens.

In many cases the development of an aortic thrombus is the first symptom of feline heart disease. In other cases, cats may suffer from coughing, breathing difficulties, or an inability to be active. Sadly, for some cats sudden death from acute heart failure is the first symptom of HCM.

There are two known causes of HCM. The disease has a hereditary component and it tends to run in families. Also, there is a dietary link. Cats with diets that are deficient in an amino acid called taurine are prone to the syndrome.

Yael, if your kitten milk had inadequate taurine that could be the cause. However, the need for taurine in cats has been well known for many years, and all self-respecting producers of cat food products have been supplementing taurine for years. I’m therefore more suspicious of a hereditary form of HCM in your family.

Either way, it’s in your cat’s best interest to undergo an echocardiogram (ultrasound of the heart). This will allow you to treat HCM if it is present. Or, hopefully, it will allow you to rest comfortably with the knowledge that your remaining cat is not affected.