By Dr. Donna Spector for VetStreet

According to the Association for Pet Obesity Prevention (APOP), approximately 55 percent –- 47 million -- of U.S. cats are overweight or obese. APOP reports that most cat owners do not seem to realize when their pets are overweight, and “fat cats” have become the dangerous new normal. We must address this weighty issue for the health of our feline friends!

Most domestic cats should weigh between eight and 10 pounds, although some breeds have larger ranges. For example, Persian and Siamese cats can range between six and 12 pounds, and Maine Coon cats can be normal at up to 25 pounds. But these are the exceptions rather than the rule.

An obese cat is defined as one who weighs more than 20 percent above their ideal body weight.

When a vet recommends that a cat lose two or three pounds, it often goes in one ear and out the other. Who doesn’t have a few pounds to lose? But that is us thinking in human weight terms.

Here’s what a few extra pounds on a cat would equate to in a human:

Two pounds is similar to 28 pounds on a 140-pound woman

Three pounds is similar to 42 pounds on a 140-pound woman

Five pounds is similar to 70 pounds on a 140-pound woman

Eight pounds is similar to 112 pounds on a 140-pound woman

Obesity contributes to many medical conditions in cats such as diabetes, arthritis, heart and lung disease, high blood pressure, compromised immune function and may even predispose them to certain types of cancer. It has been well documented that cats maintaining an ideal body weight live longer, and with less disease, than overweight cats.

Obesity Causes

While some cats have medical conditions predisposing them to obesity, obesity is most often a result of simple overfeeding. An average 10-pound cat usually needs only 180 to 200 calories each day. Cats do not feed themselves -- pet owners are responsible for what cats are eating and how fat they are getting.

Cats are typically overfed their cat food, and the APOP reports that treats continue to be a major contributor to weight gain in cats. A recent survey revealed 93 percent of all pet owners give treats, with 26 percent of those giving treats three or more times each day. Unfortunately, even small treats often hide a significant amount of calories.

What Foods Help Cats Lose Weight

Many dry cat foods are very high in calories, with 400 or more calories per cup, making it very easy to overfeed a cat unknowingly. As strict carnivores, it is often easiest and healthiest for cats to lose weight on high-protein, low-carbohydrate canned food. These foods allow cats to lose weight while still maintaining lean body mass and strength. Treats must also be chosen wisely, and high-carbohydrate, high-calorie treats must be avoided. No more than 10 percent of a cat’s daily calories should come from treats.

Many owners have no idea how many calories their cat is eating because they are in the bad habit of “free feeding” their cats, filling up the food bowl whenever it gets low. It is best to meal-feed cats with a precise measuring cup to get the calories just right.

5 Ways To Help Kitty Lose Weight

5 Ways To Help Your Cat Lose Weight See Gallery

Check out Association for Pet Obesity Prevention (APOP) for more tips on feline weight loss.

Dr. Donna Spector is a board-certified internal medicine specialist who practices in the northern Chicago area. She also owns a consulting business that focuses on bringing specialty veterinary care to underserviced regions, providing consultations directly to pet owners and their veterinarians.