Not sure how similar a cat is to a dog with regards to the circulatory system. We had two birmans, brother/sister twins. One a little over a year ago started having weakness in his hand legs. Started falling, etc. One cause of this is a clot in the artery that goes to the hind legs. The artery splits when it gets to the hips and of course becomes smaller, causing the clot to lodge in that area, leading to weakness of the rear legs and eventually worse.
He ended up dying May of last year.
His sister started exhibiting the same symptoms a couple months later and soon after died. Sucked. What're the odds of the same cause being the cause of death of two cats within a couple months?