First time on this web site. I have a 6 year old male Maine Coon (cat), who has been the most lovable cat. Tonight he started hissing at our other cats for no reason. We have a kitty box available, and "Big Kitty" never uses it. He has always gone outside to do his business. He's been in and out of the kitty box all night, and nothing is happening. Then he goes under the coffee table to clean himself and he growls, like he is in pain. He is a large cat, 26 pounds, as most Maine Coon's are big cats. He has always ate Science Diet 7+ years, just because our other cats eat it, and all have remained healthy. Does this sound to anyone like beginning kidney failure? Any info would be appreciated.
Thanks, Moussie51