Arterial thromboembolic disease, which is also sometimes called aortic thromboembolism or a saddle thrombus, is a disorder that most commonly affects cats suffering from heart disease. Poor circulation of blood through the heart chambers causes blood clots to form. These clots then can break off and travel through the cat's arteries. A common place for them to lodge is in the vessels that supply blood to the hind legs.
Affected cats are in excruciating pain and will often howl and cry. In most cases, their rear legs are paralyzed and both hind feet are cool to the touch. If a clot does not completely block off the flow of blood, some movement may be possible or one side of the body may be more severely compromised than the other side is. A veterinarian will often make a tentative diagnosis of arterial thromboembolic disease based on a cat's clinical signs alone, but blood work, x-rays of the chest and back and an ultrasound of the heart is often necessary to rule out other disorders or injuries that may present with similar symptoms and to determine the cat's prognosis and appropriate therapy.
Treatment for arterial thromboembolic disease includes pain relief, supportive care (e.g., intravenous fluid therapy) and medications that can help dissolve blood clots and prevent others from forming. Some affected cats can recover use of their hind legs, while others will never be able to walk normally or may die despite aggressive treatment. The cats that do recover are at risk for developing more clots, particularly if their underlying heart disease cannot be effectively managed.
Written by: Jennifer Coates, DVM
Last reviewed: October 2, 2008