Feline Aortic Thromboembolism

​Feline Aortic Thromboembolism (fATE) is a serious condition that is the result of severe heart disease in cats. As heart disease progresses it can cause the upper heart chamber (left atrium) to enlarge. This enlargement causes disturbances in the blood flow that can lead to formation of blood clots. The blood clot can pass into the left ventricle and be pushed out into the aorta. The aorta is the major blood vessel that carries oxygenated blood out to the body and organs. The aorta travels from the heart to the pelvis where it forms a “Y” creating the iliac arteries that supply blood to the hind legs. Clots often lodge at this point, smaller clots may travel into one of the iliac arteries affecting only one hind leg, while larger clots block blood flow to both hind legs, this is often call a “Saddle Thrombus”.

Symptoms

​Sudden paralysis of one or both hind legs
Severe pain/vocalizing
Weak or nonexistent pulse in affected leg(s)
Cold hind leg(s)
Blue nail beds and paw pads in affected leg(s)
Increases respiratory rate and effort
Congestive heart failure (CHF)

Diagnosis

​An ultrasound of the heart (echocardiogram or echo) will allow the cardiologist to assess the heart structure and function. In some cases the blood clot, or evidence of blood clot formation can be detected. Chest x-rays will show fluid accumulation within or around the lungs and may be recommended if congestive heart failure is suspected. Blood pressure, blood work and Electrocardiogram (ECG) should also be assessed.

Treatment

​Treatment includes hospitalization with pain control and anticoagulant medications to help reduce recurrence of blood clot formation. Many cats with fATE are also in congestive heart failure and medications for heart failure are also started. If only one leg is affected or partially affected the prognosis is better than if both hind legs are affected. Unfortunately, cats with a saddle thrombus are high risk of additional clot formation in the future despite medical management.