I need to know what i can do to help my cat. He is 5 years old, seems to be rather lethargic or depressed. he had a well kitty exam 2 weeks ago for the first time since he was born and it turned out fine. no feline diseases or such. he had his vaccinations too. I worry because i have had bad luck with cats and keeping them well. He usually likes to play and cause trouble but he is not doing that. When or what should I be concerned about.. He loves tuna but he did not eat alot of it like normally he does. And He just does not seem to be himself. It has been hot here where we live but we keep the A.C running often.. also does any one know what the signs of urinary infection or inability is in cats??