Sadly, last Friday morning, my Grandcat, Mr. Kitty, suffered a sudden onset of Saddle Thrombus and passed away.
Saddle thrombus (or saddle thrombosis) is a blood clot that starts off in the left atrium of the heart and then moves out into the aorta (aortic thromboembolism). Once there, the clot travels to the junction of the aorta and into the iliac arteries where it gets stuck. Since the iliac arteries feed into the femoral arteries, which serve the back legs, the clot prevents blood flow to the back legs and is an extremely serious condition.
90% of the time, saddle thrombus is related to an underlying heart condition such as dilated or hypertrophic cardiomyopathy (types of congestive heart failure).
The main symptom is weakness or paralysis of the hind legs, which will be colder than other parts of the body and may even be bluish in color. The cat will be in a lot of pain, often vocalizing his discomfort loudly. Go to your veterinarian or an emergency clinic immediately if your cat has these symptoms.