Heart disease is the biggest killer of people, but did you know it also kills pets? In people with heart disease, clots in the blood, called thrombi, can restrict circulation to important organs, causing problems like stroke or heart attack.

Thrombi also form in cats with heart disease, but in 90 percent of cases the clot forms where the body’s largest artery, known as the aorta, splits to provide blood flow to the rear legs. This is called a saddle thrombus, because the clot saddles the aorta as it branches in two.

Affected cats often cry from pain and are unable to use their rear legs, which are typically cold and stiff from lack of circulation. This is a true emergency that can lead to death if left untreated, so if your cat shows any of these symptoms, contact your veterinarian immediately.