One in three Americans are clinically obese, and it turns out that too-heavy dogs and cats in America are even more common.

More than 50 percent of U.S. cats and dogs are obese or overweight, according to a survey of veterinarians by the Association for Pet Obesity Prevention.

It seems that as Americans have gotten fatter, our pets have too, and our four-legged friends are vulnerable to the same weight-related disorders as humans.

"We continue to see an escalation in the number of overweight cats and an explosion in the number of type 2 diabetes cases," said Ernie Ward, veterinarian and founder of the APOP.

The prevention group says that approximately 80 million U.S. cats and dogs are at an increased risk for weight-related disorders such as diabetes, osteoarthritis, hypertension and many cancers.

An estimated 43.2 million cats or 58.3 percent are overweight or obese and 36.7 million dogs or 52.5 percent are overweight or obese, according to data taken in the 2012 survey of 121 veterinary clinics in 36 states as well as 2012 data from the American Veterinary Medical Association.

There may even be a correlation between fat dogs and fat people, as evidenced by the numerous photo blogs of dogs who look like their owners and a study that found people could correctly predict the type of dog a person owned based on their physical appearance.

The U.S. Centers for Disease Control and Prevention reports that that 35.7 percent of Americans are obese and that 17 percent of children aged 2-19 nationwide fit the clinical definition of obese.

Veterinarians see a clear connection between obese children and pets.

"The causes of pet and childhood obesity are largely the same: too many high-calorie foods and snacks combined with too little physical activity. Parents need to encourage children to put down their video games and pick up the dog leash to go for a walk. Instead of snacking on sugary treats, share crunchy vegetables with your dog. Eat more whole foods instead of highly processed fast food," said Ward.

The recent story of Obie, the morbidly obese dachshund that got a new shot at life after a dramatic weight loss and the resulting surgery to remove several pounds of excess skin, was one example of pet obesity that garnered tremendous public attention. But Obie, who's former owners nearly killed him with generous overfeeding, is not alone.

In the survey, 45 percent of pet owners assessed their pet to have a normal body weight while veterinarians assessed the pet to be overweight.

Ward called the misestimating of healthy pet weight the "fat gap."

"The disconnect between reality and what a pet parent thinks is obese makes having a conversation with their veterinarian more challenging. Many pet owners are shocked when their veterinarian informs them their pet needs to lose weight. They just don't see it."

RELATED: Obie's Journey: Dachshund Gets Tummy Tuck After Epic Weight Loss [VIDEO]