A blood clot is a common occurrence in cat's with heart disease and is the result of the inadequate pumping of blood through the chambers of the heart. Blood clots travel through the blood stream until they eventually become lodged in an artery. This is called a thromboembolism.
In cat's, the most common area for clots to lodge is the the aortic junction between the rear legs. The clot cuts off the blood supply to both legs resulting in paralysis. Your cat may show signs of extreme pain and his feet and legs will be cold to the touch.
Cats are usually in severe pain and extremely agitated. Initial treatment will involve pain medication, blood thinners and aspirin. Many cats are sedated if they can tolerate the anesthetic.
Treating the underlying heart disease will be paramount in the treatment plan and includes oxygen therapy, diuretics to prevent fluid build-up, nitroglycerin to dilate the blood vessels and a medication to regulate the heartbeat.
Dissolving the Clot
There are no drugs on the market that are considered safe to use on cats to dissolve clots. The clot will eventually dissolve on it's own; the body adapts to the injury by increasing the blood flow to other vessels in surrounding tissue.
Most cats will eventually die from the underlying heart disease; it is estimated that 90 percent of cats will have a repeat episode of thromboembolism within six months.