Don't put your pet on a senior food or a "light" diet just because it is at a certain age. Diets formulated with the older pet in mind frequently contain fewer calories, 18% less protein and 4% to 6% less fiber.
Cats may vocalize for any number of reasons, if they are afraid, in pain, distressed, anxious, nervous, angry, or if they just want to complain.
The correct first step for a senior pet with a problem has been taken—a trip to the veterinarian for a physical examination, history taking, and urinalysis. Urine may also be sent out for a laboratory culture to check for low-grade infection.