Originally Posted by GuardianAngel;3669242;
I've had cats for several years now, but grew up being a dog owner.
I'd go ahead and bring Louie into the vet. Could be kidneys - renal. Both cats and dogs hide their sickness. So, you don't know until it's advanced.
I'd keep a close watch on how much water he is drinking. If it is a kidney problem, he will be drinking a whole lot.
Whatever you do, try to get him to eat. Do not withhold food.
Good Luck and please report back