In most cases a healthy appetite indicates your pet is not suffering from illness, however, there are some diseases that are often associated with increased appetite in dogs and cats. A healthy appetite can fool pet owners into thinking that their pet is generally healthy, when disease is actually at work.
One of the most common causes for increased appetite is diabetes both dogs and cats. Initially diabetes will frequently cause a pet to feel hungry, until diabetes progresses to a point where pets eventually become severely ill and anorexic if this disease goes on untreated.
Increased hunger can be a result of digestive disorders that are associated with impaired digestion or impaired absorption of nutrients. Pancreatic insufficiency is a digestive disorder whereby the pancreas does not produce enough digestive enzymes to properly break down ingested food into smaller nutritional units, preventing these nutrients from being absorbed properly in the intestine. Increased hunger can also be the result of impaired absorption of nutrients by the lining of the small intestine. Diseases ranging from intestinal parasites to inflammatory bowel disease to certain forms of cancer can impair of the ability of the cells that line the intestine to absorb nutrients. Either impaired digestion or impaired absorption of nutrients can often cause an increase in appetite.
A very common disease affecting older cats is hyperthyroidism. In this case a diseased thyroid gland produces excessive thyroid hormones causing increased metabolism and hunger. Older dogs can develop problems with an “over active” adrenal gland that often results in increased hunger, along with various other symptoms including increased thirst.
While pets affected with any one of this diseases seem to eat a lot, they often lose weight despite their hearty appetites. If your pet seems to have an unexplained increase in appetite; especially if there seems to be associated weight loss, be aware that your pet may actually be sick.