Description

Obesity is defined as body weight in excess of 15% above normal

resulting from the accumulation of fat. It occurs in 25-50% of

cats in the United States. Associated health risks include fatty liver

syndrome, diabetes mellitus, musculoskeletal and cardiovascular

diseases, high blood pressure, high fat levels in the blood, possible

anesthetic and surgical complications, decreased heat tolerance

and stamina, and reproductive problems.

Causes

Obesity occurs when energy intake exceeds energy expenditure

and other risk factors are present, such as neutering and dietary

factors. Feeding calorically dense, highly palatable, high-fat diets

and free-choice feeding increase the risk of obesity.

Clinical Signs

Affected cats have excessive fat accumulation around their neck,

over the tail-head, along the underside, and in the abdominal cavity.

Difficulty moving or breathing, exercise intolerance, urinary

or fecal incontinence, unkempt appearance, and pressure sores

may occur.

Diagnostic Tests

Cats are usually tested for liver disease and diabetes mellitus

(sugar diabetes). Other tests may be recommended to assess for

obesity-related diseases in other organs.

Treatment Options

Weight reduction programs involve a multistep approach that

includes good owner commitment, a feeding plan, and an exercise

plan. In order for the animal to lose weight, it is necessary

for energy expenditure to be greater than energy intake. This is

accomplished by increasing exercise and by feeding a diet that is

lower in fat and higher in fiber.

Nutrients in diets formulated for weight loss in cats are

designed to decrease energy intake, so that weight loss occurs

without inducing other nutrient deficiencies. In order to achieve

weight loss, a diet is fed that meets resting energy requirements

of the cat at its ideal weight. Weight loss is better achieved with

meal feeding rather than free-choice feeding. It is also important

to limit treats and not to allow access to other pets’ food or to

human food.

Alternatively, diets that are higher in fat and protein and lower

in carbohydrates compared with adult maintenance foods can

be fed. When feeding this type of diet, food intake must also be

decreased. A low-fat, high-fiber diet can be started, and if weight

loss is not achieved, the alternative diet can be tried.

Getting a cat to exercise can be difficult. It helps to place meals

in locations that force the cat to climb up or down or to jump.

Some cats will chase toys or lights, and feeders are available that

force the cat to play with them in order to reach the food.

Getting a cat to lose weight in a multicat household where

other cats are not obese is even more difficult. Feed the obese cat

separately from the nonobese cats. The nonobese cats’ food can

be placed in a large box with a narrow opening that is too small

to allow the obese cat to enter. Radiocontrolled devices can be

used that allow the nonobese cats (who wear special collars)

entry into areas through a gate that has a radio receiver. Pick up

leftover food so that the obese cat does not eat the other cats’

food.

Follow-up Care

Body weight is monitored every 2 weeks during weight loss, and

the diet and exercise are adjusted to achieve a loss of 1-2% of body

weight per week. Many cats lose weight in a stairstep fashion:

They lose quite a bit over the first 2 weeks, do not lose much over

the next 2 weeks, and then lose quite a bit again. Alterations in

diet are not usually made unless weight has remained unchanged

at two sequential examinations. Laboratory tests are done periodically.

If the cat also has diabetes, fructosamine and glucose tests

may be recommended. Insulin dosage may need to be decreased or

discontinued over time as weight loss occurs.

When the desired target weight is reached, body weight is

monitored monthly to ensure the ideal weight is maintained. The

maintenance diet is usually an adult diet designed to maintain the

lower weight. These diets are typically higher in fiber and lower

in fat than most over-the-counter, adult maintenance diets. Certain

diets labeled as light may be used, but they are not as effective.

The alternative weight-loss diet (high fat and protein, low carbohydrate)

can also be continued. Treats, snacks, and table scraps

should comprise less than 5% of total caloric intake.

Prognosis

Weight loss is more difficult to achieve in obese cats than in obese

dogs. Working with a veterinarian is important because of the

many obesity-related diseases that occur in cats. Prevention of

obesity in growing cats is also very important.