Pet Obesity


Over half of pets are considered overweight or obese, and according to studies, the number is climbing every year. It is the most common concern for pets in our society today when it comes to nutrition-related health.

The obvious, and most primary, cause of obesity is too much food and not enough exercise. As pet’s overeat without burning off excess calories, the calories become stored as fat. For some owners, it’s difficult to recognize that their pet has slowly become overweight until they visit their veterinarian for another reason. This creeping weight gain can be subtle and dangerous.

Sadly, pets that are overweight or obese may have difficulty breathing, walking, playing, exercising, and tolerating heat, just like humans.


Your veterinarian will give suggestions for weight loss. They should also recommend overall health examinations and tests along with possible diagnostic tests to determine the best, and safest, treatment for your pet’s obesity.
A diagnostic test will likely include:

  • A veterinary exam that includes a measure of body weight and a body condition score. A review of past body weight and its incline may be helpful in detecting a pattern in weight gain. It may even help identify a certain event or environmental change that relates to the weight gain.
  • Routine blood work that contains a serum profile and complete blood cell count. These and a urinalysis are needed to find out if there is any underlying disease. If these are normal, a weight loss program can begin. Otherwise, if the results show a problem, more diagnostics may be needed for further identification before a program can be safely applied.
  • An assessment of your pet’s complete daily caloric intake and exercise schedule. It’s important to calculate any and all food, treats, snacks, and table foods your pet ingests daily and see if their regular exercise balances it out. If the calories exceed the amount of energy burned by activity, it’s clear that this is the cause, or at least a great contributor, of the pet’s obesity.


It is recommended to treat any disease that affects obesity.

  • You can easily lower your pet’s caloric intake by changing the type of food to a diet formulated for weight loss. Whether you change the type of food or not, it’s a good idea to change the amount you feed to the amount recommended by your veterinarian.
  • An increase in fiber or water intake may be needed to keep your pet satiated.
  • Increase your pets exercise activity. This can include long walks to vigorous play. A variety of leashes and toys are available to improve activities.


Weight loss will only be successful if it is considered a family endeavor. Your family must all agree and admit that the pet is overweight and commit to the pets weight loss program. It might be a good idea to make just one person in charge of the feeding of the pet. Also, monitor how many treats the pet is getting. The family could even keep a log to keep track of food intake and exercise.

If your pet is obese, you need to change their food to a diet specifically designed for weight loss. If you simply change the amount of food you feed your pet, it’s not likely you’ll get a significant amount of weight loss. One way to find out the right amount to give your pet is by checking the bag to see if they have a measurement specifically for overweight pets. However, the best thing to do is consult your veterinarian for advice. Treats should be minimized as well. The best treats to give an overweight pet is something light, like air popped popcorn or pieces of vegetables (like carrots).

Medical progress exams with your veterinarian are very important to keep up with every 4 to 6 weeks to monitor weight loss. Adjustments to the feeding plans are often needed and, as your pet approaches their ideal body weight, caloric intake will need to be reduced further to maintain the weight loss.

The majority of pets will need an 8-12 months weight loss program to get to their ideal weight. This can only be achieved when the owners and all family members are committed to improving their pet’s health. When the pet reaches their goal, most owners will continue to feed them the weight management diet, but at a larger food dose. That way the pet maintains their ideal weight.

Recommendations depend on the underlying disease. For obesity due to:

  • Excessive caloric intake. After the pet’s ideal weight is reached, the low-calorie diet should be continued, treats should keep being regulated, and the exercise program should continue.
  • Diabetes mellitus. Medical progress exams are needed to monitor insulin dose and effectiveness, and to measure any changes in the pet’s weight.
  • Hypothyroidism. Medical progress exams are needed to keep track of thyroid dose and effectiveness, and to measure any changes in the pet’s weight. If the pet is losing weight, blood thyroid levels should be checked as well.
  • Hyperadrenocorticism (Cushing’s disease). Medical progress exams are needed to monitor medical management, and to measure any changes in the pet’s weight.


Obesity in pets more commonly is due to over-eating than disease, but whether your pet is obese due to an overfeeding problem or an underlying disease, in the end they are still consuming more calories than they are using. These excess calories are stored as fat by the body.

Some other causes of obesity are due to a changed energy metabolism. The following are diseases that contribute to obesity:

  • Diabetes mellitus. Overweight and obese animals will become insulin resistant. The early signs of diabetes mellitus in an animal are an increase in hunger, thirst, and urination. The pet will eventually lose weight as the disease progresses.
  • Hyperadrenocorticism (Cushing’s disease). This disease happens when the pet’s adrenal glands produce too much of the hormone cortisol. Pet’s with Cushing’s don’t usually gain weight, but will have fat redistributed to the abdomen, causing a pot-bellied appearance that looks like weight gain.

You want to talk to your veterinarian if you think your pet is overweight, experiences difficulty breathing, exercising or getting comfortable. They will be able to determine if any of these abnormalities are present before beginning a weight loss program.


Your veterinarian will want to perform diagnostic tests on a pet that is overweight or obese to determine if there are any underlying problems. These include:

  • A comprehensive physical examination with a precise measure of body weight and a judgment of body condition score.
  • Review of your pet’s intake of food, treats, and table scraps daily along with exercise.
  • Routine blood work that will show a serum profile, complete blood cell count, and urinalysis. With normal blood work results, the obesity is likely the result of excessive calorie intake, and reduced energy use. However, if the test results are abnormal and indicate a problem, more tests would be needed for an accurate diagnosis. These additional tests may include:
  • Urine cortisol:creatinine ratio. The disease Hyperadenocorticism should be suspected with a high ratio.
  • ACTH stimulation test. For a better diagnosis, an adrenocorticotrophic hormone stimulation test is used.
  • Low dose dexamethasone test. This test gives the doctor a definitive diagnosis of hyperadenocorticism and is used in concert with the urine cortisol:creatinine ratio and an ACTH stimulation test.


Before you start your pet on any kind of exercise plan, make sure you talk to your vet to rule out any major disease that could be causing the obesity.

Recommendations for obesity due to excessive caloric consumption:

  • Change your pet’s caloric intake to 50 percent less than what your pet needs for his ideal body weight.
  • Here is an idea what to check on the food before you buy it:
  1. less than 340 kcal per 100 grams of food on a dry matter basis
  2. between 5 to 10 percent fat for dogs, 7 to 12 percent fat for cats
  3. between 10 to 30 percent crude fiber
  4. reater than 25 percent crude protein for dogs, greater than 35 percent crude protein
  • Keep our pet on this diet with the prescribed amount numerous times daily.
  • Give treats sparingly only as directed. It’s best to use low calorie treats or vegetables.
  • Increase your pet’s daily exercise.
  • Swimming is an excellent way for a pet to lose weight and it also helps patients with orthopedic disabilities, so try to get them to swim.
  • Visit your veterinarian monthly for a medical progress exam and so any adjustments to the diet or exercise can be made.

Recommendations for obesity due to diabetes mellitus:

  • When controlling diabetes, a special diet will most likely be required. The new pet food should have a moderate level of fiber (5 to 10 percent) with lowered levels of readily available carbohydrates.
  • Insulin treatments will vary depending on the patient.
  • Sometimes in patients with diabetes, a pet will lose weight. This usually means the clinical signs of diabetes are no longer there and treatment is unnecessary.
  • Recommendations for obesity due to hyperadenocorticism:
  • Any pet with ACTH need to do medical progress exams every 3 to 4 months. The treatment will usually involve maintenance medication doses.
  • Generally, a weight loss program is unnecessary to arrive at an ideal body weight.

Pet Obesity