But there may be a medical cause, especially if weight gain is rather sudden. Thyroid condition can cause changes in your cat s metabolism and he may eat as if he were starving and still lose weight or he may gain weight for no apparent reason. At any rate, if you suspect a medical cause, don t hesitate taking your cat to the vet right away. The average indoor cat needs only 4 to 7 ounces of food per day. There are numerous low-cal cat foods on the market in both dry and canned foods.
Dry foods tend to have a higher fat ratio, but most cats deal with it well.
There are now lower fat dry foods available too. The really obese are obvious, but some are more capable of appearing svelte. Your cat is overweight if his abdomen isn t parallel with the floor, but sags. And you thought that jiggle in his walk was cute. You should be able to feel your cat s ribs too, but some cats carry their weight higher or lower along the abdomen.