My cat can't move his hind legs

My cat just had surgery a week and a half ago.  He had about 8-10 inches of his intestines cut out because it was inflamed and had abrasions.  He's been home for the past week and has been doing fine.  All of the sudden this morning, he can't use his hind legs when walking.  He is dragging his hind legs.  I don't know if this is probably a reaction from his surgery. Does anyone have any idea of what may be going on?

I would take him to the vet very soon, I would treat it as an emergency.  There is a condition called saddle thrombus which is caused by blood clots which can cause this.  It is extremely painful.

I agree sounds like saddle thrombus -- a blood clot in the aorta.  Emergency vet immediately if you haven't done so already.  It's life threatening.

"Once the doctor determines that the cat most likely has a saddle thrombus, further diagnostics will be needed as well as treatment. The cat will need medication for the pain and medication to reduce the ability to clot. Usually treatment is started with injections and changed to oral after the cat is eating. The pain of the condition generally is subsiding after the first 24 hours and the muscles become softer after 2 to 3 days."