Feline thrombosis is a multiple disease of the heart and blood vessels. There are no obvious symptoms in the early stages of the disease. When the disease occurs, it is more common in the hind legs or limbs, and it will cause sudden paralysis. Cats with blood clots will be unable to walk on their hind legs and will drag themselves when walking. After a cat is confirmed to have a blood clot, it must be treated promptly, otherwise the mortality rate will be high.