We’ve talked many times previously about heart disease in both cats and dogs. Dogs usually make it a little easier for us veterinarians to spot because they tend to follow the book in terms of heart disease. Canine heart disease is often indicated by a heart murmur, but in cats, this isn’t always the case.
Cats have heart murmurs that are completely innocent, or they can have advanced heart disease without even the faintest of murmurs. This is concerning to me both as a veterinarian and as a cat owner because undetected heart disease can lead to a very serious emergency called feline aortic thromboembolism (FATE), or saddle thrombus.
The aorta is a very large artery that carries blood from the heart. It travels down the back and then splits at the hind end of our pets to supply both hind legs with blood. The area where the aorta splits is known as the “saddle.”
When heart disease is present, there is usually turbulent blood in the heart. Turbulent blood favors the formation of blood clots in the heart, off of which tiny clots can break and travel in the bloodstream. When a blood clot lodges in the saddle area, we call this a saddle thrombus.
A clot in the saddle region cuts off blood supply to the hind legs of the affected cat. This condition is extremly painful for the cat. Affected cats are generally paralyzed in one or both hind legs and vocalize loudly in pain. This condition is an emergency – if your cat displays symptoms like these, get him to your regular veterinarian or emergency clinic as soon as safely possible.
Sadly, 75% of cats that present with a saddle thrombus had previously undetected heart disease – that’s how good cats are at hiding their problem.
The prognosis for saddle thrombus is variable and depends largely on the general health of the cat, and whether heart failure is present. Most cats are likely to have a repeat saddle thrombus at some point in their lives, so therapy will begin to try to combat that possibility.
The first order of business in treating a saddle thrombus is to address the pain. Your veterinarian will want to give pain medications to help your kitty rest a little more comfortably before delving into other treatments. The next thing on the agenda is to try to dissolve the clot to restore normal blood supply to the hind legs. During this time, your cat will need to stay in the hospital, where he will receive anti-coagulants, pain medications and other supportive therapy.
If the clot can be dissolved, management options will then be discussed. Your vet will likely recommend an echocardiogram to assess the heart. Medications to treat heart disease will be started to help the heart perform more efficiently, and anti-coagulant drugs such as aspirin or Plavix will help prevent future thromboembolic events.
Sadly, depending on the severity of the case, successful treatment of this condition is not always possible. Your veterinarian will present all of the options and together you can decide on the best one for your family.