Saddle Thrombus (Blood Clots) in Cats

For those of you who have never heard of an “aortic thromboembolism,” sometimes called a “saddle thrombus,” it occurs “when a blood clot is dislodged and travels through the aorta, becoming lodged in a distant location.”1 

- Jean Aldrich

It is also a life-threatening emergency for your cat.

How Does It Happen?

“Saddle thrombi are most common in cats with heart disease. This is because cats with heart disease often develop large clots inside their hearts that release small clots into the bloodstream. Other, less common causes include hyperthyroidism and cancer.” 2

Symptoms of this condition include but are not limited to: sudden collapse and seeming paralysis of the (usually) back legs, although sometimes a front leg is affected. The cat appears to be in pain and may want to drag herself to a hidden “safe” place, as she has no idea what is happening to her. Occasionally this condition is presaged by weakness and lameness. Other signs can be a weak pulse in the back legs or even lack of a pulse in the back legs. The back paws may feel noticeably cooler than the front paws; the cat’s core body temperature may also be lower than normal. This is an emergency situation! A cat showing these symptoms should be taken to a vet or emergency clinic immediately!

Treatment and Prevention