Sudden Weight loss in Cat.

Question
I have a Male cat who is 15 years old, very healthy and active, eats well. All of a sudden he is skin and bones. He still has good appetite, any Ideas?

Answer
I would recommend a check up at the vet.  Older cats can get thyroid tumors that cause excessive thyroid hormone to be secreted.  That can cause profound weight loss.  The other thing in a 15 year old cat that can cause this is kidney problems.  YOur vet will want to do some blood work to see if there is something that can be fixed to counter the weight loss.  Thyroid tumors are easily removed, while kidney disease is usually progressive and very hard to deal with.