Can you feel the animal's spine and ribs fairly easily? When you look at the top of your pet, can you see a narrowing between his midsection and tail -- or a "waist"? When you look at your pet from the side, do you see a "tuck" in the tummy at the bottom of the ribcage? If you answer no to any of these questions, then it's time to see the vet and take action. It's great to get out and throw the ball for 20-30 minutes a day for dogs, or take Fido for a long walk - it'll do both of you some good. Increase fat cats' indoor activity by tossing small catnip toys or capturing their interest with bits of string, paper, etc. Limit table food and treats for animals, and ask your vet if a change in your pet's diet is necessary.