Americans are passing on the battle of the bulge to their pets.
"Fifty percent of all people and 50 percent of all pets are overweight or obese for the same reasons -- eating too much and moving too little," said Dr. Marty Becker, a veterinarian who appeared on "GMA Weekend" to teach owners how to care for overweight pets.
Corpulent canines and fat cats aren't cute; they are unhealthy and in danger of an early trip to pet purgatory, Becker said.
"If you keep your pets thin, studies show they'll live 15 percent longer -- that's about two extra years on the average," said Becker. "I'm not exaggerating when I say that pets almost never come to the veterinarian's office too thin."
Becker said there are three reasons why pets get fat:
They eat the wrong food. There's only one type of food your pet should eat, and your veterinarian can help you figure that out based on your pet's breed, age, lifestyle and health risks. Vets probably will change what a pet eats five times during its life, as it ages. It is impossible for consumers to weed through the tantalizing ads and competing claims to make sound choices for their pets.
They eat too much food. Pet owners underestimate how much their pets are eating, especially as it relates to how many calories they're burning. A lap dog lying in a lap doesn't need a lot of calories -- but a lap dog training for a marathon with its owner does. Sometimes, pets eat more than the owners know. Dogs can raid a cat's bowl, and all kinds of pets might get treats on the sly.
They eat too many treats. Nobody wants to stop giving their pet treats. But limit the treats to 10 percent of the pet's daily caloric intake. Try to substitute healthy treats like baby carrots, which are sweet and crunchy but have no empty calories. Also, offer "emotional milkbones" in which you tell your pet how great it is along with a smaller portion of treats.
Here are some signs your pet is overweight, according to Becker:
Your pet has breathing problems and pants a lot.
Your pet has difficulty jumping and climbing stairs, often from secondary joint problems.
Even with these clues, most people are in denial that their pet is overweight. Becker pointed to a body-scoring assessment you can do at home, or ask your vet to do. Here's where to look to see if your pet is to fat:
Ribs check: You should be able to easily feel your pet's ribs. They shouldn't be covered with a layer of fat.
Profile check: When your pet is standing and you're viewing it from the side, you should see a tucked abdomen, not a body that looks like a cylinder.
Overhead check: When your pet is standing and you're viewing it from above, you should see an hourglass shape with a clearly defined waist.
Tail check: You should be able to feel the base of the tail very easily.
Becker offered tips to downsize your pet:
Feed your pet "weight reducing" food. To get rid of the extra weight feed the food your doctor recommends -- which many be a special weight-reducing food like prescription diet R/D or W/D.
Don't feed "free choice" -- which means there is food available all the time and your pet eats whenever it wants. Instead, take the amount of food your doctor recommends and divide it up into two or three meals.
Spread meals across the day. Dogs that eat once a day are much more likely to be overweight. By splitting up the food throughout the day, you can make sure your dog never gets too hungry.
Limit snacks and access to other food -- just like in a human diet.
Start a walking program. If your overweight pet is really out of shape, don't push it too hard. Start with one block per 10 pounds of body weight, twice a day. Early morning or evening walks are best -- avoid scorching sidewalks, high heat and humidity.