America is obese, but not just the humans - the pets too!

Over half of U.S. pet dogs and cats are pudgeballs and one out of every five is considered obese, according to the Association for Pet Obesity and Prevention.

Overweight and obese pets are at increased risk of osteoarthritis, insulin resistance, type 2 diabetes, hypertension, heart disease, respiratory problems, cranial cruciate or anterior knee ligament injury (the dog version of a torn ACL), kidney disease and cancer. Obesity can take two-and-a-half years off of your pet's life - which is a big chunk of time for an animal.

And diabetes in dogs and cats is on the rise. In 2011, The Dog Channel wrote that there has been, "a 32 percent increase in the rate of canine diabetes mellitus and a 16 percent increase in feline diabetes mellitus since 2006.

"The rise in cat and dog diabetes mimics a similar jump in human diabetes, which according to the Centers for Disease Control and Prevention, has increased at a rate of 28 percent since 2005."

"For cats, you'll see they're reluctant to play and they are unable to enjoy life," senior veterinary surgeon Sean Wensley told CBS News.

One way to tell if your pet is fat is to use the scale. If you can't keep Fido or Fluffy on the scale by themselves (using a treat to bribe them would be counterproductive), the easiest way is to weigh yourself first, then weigh yourself while holding your pet. Subtract the smaller weight from the larger and the result will be your pet's weight.

A body conditioning score can help you determine your pet's weight without a scale.

Visits to the vet are important too, as the vet can help you choose what food is right for your pet's weight and other factors, like tooth and gum health.

Portion control is just as important for pets as it is for adults. "A little piece of cheese for a cat is like giving a human a hamburger," Wensley told CBS News.

And exercise! Take your dog for a walk or play with your cat. Moving is good for you too.