Like humans, cats may lose appetite. Sometimes the term “anorexia” is used to describe this situation. Cats may suffer from anorexia when they do not want to eat or are unable to eat. This can be a sign of physical or psychological issues.

Physical Issues

Anorexia can be an indication of physical issues, which can involve a great variety of areas, such as eyes, mouth, nose, throat, skin, brain the digestive system (including esophagus, stomach, intestine, liver, pancreas), kidneys, blood, hormones, among others.

Upper Respiratory Infections / Cat Flu

Upper respiratory infections or cat flu, a common disease for cats, can lead to appetite loss. Cats can be infected when they catch the common cold. The initial stage of the common cold includes symptoms like runny nose or occasional sneeze, and cats normally do not show signs of appetite loss.

If, however, these symptoms remain after a day or two, and/or if the cats show difficulties in breathing or unresponsive, that would indicate the cat flu become more serious, and they lead to appetite loss. The serious stage of these infections includes herpes virus, calicivirus, Chlamydia, and feline distemper.

Cat flu can be controlled by vaccination for households with a few cats. Even though this cannot thoroughly prevent cats from being infected, this is good enough to drastically reduce the harmful effect of the disease.

In case a cat is infected with cat flu in a household with lots of cats, vaccination is not good enough, and the best way is to isolate and quarantine the infected cat.

Parasite Worms

Parasite worm infestation in the digestive tract can also lead to appetite loss. Some common parasite worms include the following:

Roundworms – These are common parasites in cats. Kittens are usually more prone to the worms, and the worms are easily transmitted from female cats to their offsprings.

Kittens may not show symptoms of appetite loss when they are infested with roundworms, but the appearance of their haircoat would look poor. It is young cats that would easily lose appetite, sometimes because the heavy worm burden blocks the intestines, forcing the digested or undigested food and even feces to be stuck inside cats’ bodies.

Hookworms – These are blood-sucking worms that live in the small intestine of kittens and young cats alike. In addition to appetite loss, hookworms’ blood-sucking behavior can cause skin irritation, anemia, diarrhea and small intestine inflammation.

Intestinal and stomach Issues

Cats can also lose appetite when their stomachs are infected with viruses, or when they suffer from stomach ulcers. In fact, stomach ulcers are rare in cats unless cats’ diet is mixed with human food.

Sometimes appetite loss is not caused by viral infection or parasite worm infestation. It can be caused by physically twisted bowel in the intestine. As mentioned, the blockage of intestine usually decreases appetite. This issue can only be verified and treated by veterinarians.

Feline Diabetes

Like humans, cats may develop diabetes mellitus, a condition of high blood sugar level because the production problem of the hormone insulin from the pancreas or cells’ inactive response to insulin.

Feline (or Cat) Diabetes may be diagnosed during annual medical examination, and apart from appetite loss, the symptoms also include increased thirst and frequent urination. Sometimes the urination may be uncontrollable and thus take place outside the litter box.

Feline Leukaemia

Another disease that cats can develop like humans is feline leukemia, a cancer of blood or bone marrow because of the abnormal increase of blood cells (usually leukocytes or white blood cells).

Appetite loss, pale tongue and mouth, lethargy and prolonged disinterest in playing are the signs of the serious disease. The disease is also dangerous because it can be contagious to other cats who have not been vaccinated.

Feline Liver Disease

Liver is one of the most important and the largest organs in cats. Like other animals, it is responsible for a lot of important biochemical processes, such as regulating the levels of chemicals in the blood, producing proteins for the blood plasma, converting waste products that can be removed from the body by kidneys, regulating fats in the body, among others.

Liver disease may be possible, but the signs of the disease are usually apparent then the liver is extensively and seriously damaged. In addition, as liver executes functions that are similar to other organs, the signs that appear to be of liver disease may actually be of other organs, or the signs can be of both liver disease accompanied by the related organ(s).

Psychological Issues

Appetite loss can be a psychological issue as well as physical issue. In some cases, cats refuse food simply because they do not like the new food, or the food is not tasty to them.

Sometimes cats lose appetite out of discomfort on changes in external factors, such as changing living environment, moving to a new house, a new person in the house, visit of a new animal or addition of new pet.