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A survey by the Association for Pet Obesity Prevention found that more than half of dogs and cats are overweight or obese. Fat Cats Facebook page photo.

Here's something that might surprise you. A survey by the Association for Pet Obesity Prevention found that more than half of dogs and cats are overweight or obese.

The APOP worked with veterinarians and pet owners during the study, which found that more cats than dogs are obese. 57.6 of the cat population is obese compared to 52.6 percent of dogs, according to APOP.

Of the pets that veterinarians said were obese, 93 percent of dog owners and 88 percent of cat owners initially thought their pet was in the normal weight range, according to APOP.

Just like with humans, being overweight or obese can cause health problems for pets.

"Overweight animals also have certain health issues. It can aggravate joint disease. It can lead to type 2 diabetes. It can aggravate heart conditions," said Dr. Susan Nelson, a Kansas State University Veterinarian.

Here are a few easy ways you can tell if your pet is overweight, without putting them on a scale-

Feel along their ribs. You should only feel a thin layer of fat - much like when you rub your fingers across the knuckles of your hand when your hand is stretched out.Look at your pet from above. He or she should have an hourglass figure when viewed from above.Look at your pet from the side. Your pet's tummy should tuck up, instead of being level.Nelson says that a good way to manage your pet's weight is to watch how many calories you feed them and remember that just because a bag of pet food has certain portion recommendations, that portion might not always be the best for your pet.

Nelson says that's because some pets don't get as much exercise as research animals used for determining portion size. The amount of calories in one cup of pet food can also vary tremendously based on the type and brand.

Nelson says pet owners should look at the calories per cup on the bag and check with your veterinarian to see how much food your pet should be eating.

As a pet owner, there are a few things you can do to keep your pet fit and trim.

Exercising can help a pudgy pet lose weight. Adding a daily walk to your dog's routine and even playing with your cat can increase their activity level, according to WebMD.

Pets may look adorable when they're begging for food, but that does not mean you have to give in. Table scraps and treats equate to extra calories.

If you're concerned about your pet's weight, you can also talk to your veterinarian about it. Your vet can offer more suggestions and examine your pet. There could be a medical reason for his or her weight gain.

Some information used in this article was provided by Kansas State University.Learn more about the Association for Pet Obesity Prevention: