Increased Appetite in Dogs

4 min read

Polyphagia in Dogs

When a dog increases its food intake, to the extent that it appears ravenous most or all of the time, the condition is referred to as polyphagia.

This condition can be caused by different circumstances, and it is important to find out whether the dog’s increased food consumption is due to a psychological condition, or to a disease. Should the reason be a psychological problem, then it is likely that the dog has developed a learned behavior, which could lead to obesity.

However, if the underlying cause of your pet's increased food intake is due to a diseased state, then one of two physical effects will be observed: weight gain or weight loss.

Polypghagia can affect both dogs and cats. If you would like to learn more about how this condition affects cats, please visit this page in the PetMD health library.

Symptoms and Types

The symptoms normally associated with polyphagia include:

  • Obesity
  • Increased appetite
  • Weight gain or weight loss
  • Increased thirst (polydipsia)
  • Increased frequency in urination (polyuria)
  • An inability to properly absorb food


If the polyphagic condition is related to some sort of behavioral problem, the underlying cause could be associated with the aging process. During old age, some dogs are known to be extremely hungry. It is also possible that some form of medication that has been prescribed for your dog may be the reason for its increased appetite, and thus its polyphagia.

Polyphagia can also be the result of diabetes onset, because the body often can not assimilate blood sugar when diabetic conditions are present. Blood sugar levels can be lowered as a direct result of insulin related tumors that your dog may have developed, and this will also have a direct impact on its appetite.

It may be possible that your dog has developed poor absorption of its food within the gastrointestinal system, leading to weight loss for reasons such as inflammatory bowel problems, insulin deficiencies, or intestinal cancer. An inability to absorb food properly could cause your pet to lose valuable nutrients required for good health.


Your veterinarian will perform a thorough physical exam on your dog, and may also recommend blood tests, urine tests, radiographic imaging, organ tests, and an endoscopy.

When undertaking biochemical testing of the organs, it is possible to evaluate the functioning of vital organs like the liver and kidneys. It is worthwhile to have these tests performed on your dog, because any endocrine disorders related to insulin dysfunction will also be established, should they be present. Abnormally low blood sugar, known as hypoglycemia, may also be found, and this could be related to some forms of insulin-producing tumors that could affect the functioning of the pancreas.

A blood count will allow your veterinarian to examine the blood for the presence of infectious agents, and will also show whether your pet has developed anemia (low blood iron), or any inflammation in the vessels. Absence of these conditions may point to whether the increased appetite is due to a behavioral problem, or to a physical problem.

Your veterinarian may suggest urine analysis to evaluate whether or not your pet is losing excessive amounts of protein through its urine. A urine test will also show infection of the urinary tract, or infection of the organs involved in the waste process, as well as sugar dropped into the urine, which is commonly found in the urine of dogs with diabetes.

Your doctor may also want to perform an examintaion by endoscopy, which uses a tube that is inserted through the mouth and into the hollow cavity of the stomach (or other organ) so that a sample of tissue (biopsy) can be taken from the stomach and duodenum (small intestine).

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