Is your cat not eating? Has he lost his appetite? There are many reasons why your feline buddy is not in the mood for chowing down, even if you spoil him with his favorite meal. The causes of this curious behavior can range in importance from being a finicky eater to serious health problems as dangerous as cancer or heart disease. We will try to mention the most common health and behavioral issues affecting your cat's refusal to eat.

Most cats are infested at one time or another by intestinal parasites. Often, they recover and develop a certain amount of immunity. However, if worms are causing a disease, there should be some change in the appearance of the stool. In turn, this is reflected by a decline in the general health of the individual. You will notice decreased appetite, loss of weight, diarrhea, anemia, and the passage of mucus or blood.

An acute respiratory infection is transmitted from cat to cat by direct contact with infected sputum, nasal secretions or eye discharge as well as contaminated litter pans and water bowls. The virus may be stable for 24 hours or as long as ten days. Clinical signs appear 2 to 17 days after exposure. The first signs are fever and bouts of sneezing. Next you may see nasal and/or eye discharge. It starts out clear and can become mucoid (containing mucous) or purulent (containing pus). This signifies a secondary bacterial infection. Cats with obstructed nasal passages exhibit open-mouth breathing. There are times where you might see an ulceration of the mucous membranes of the mouth (Stomatitis). This is particularly disabling, as the cat loses his taste for food. He might refuse to eat or drink. Drooling is common.

Your cat not eating, could also be a function of a nasal obstruction. In the cat the sense of smell is used primarily for self-orientation (recognition of threatening odors) and for appetite stimulation. A nasal obstruction is almost always accompanied by a complete loss of appetite.

One of the initial signs of mouth disease in the cat is a failure to eat. This is caused by pain in their mouth rather than loss of appetite. The cat will often sit beside the food dish and give every indication of wanting to eat. He might even take food into his mouth and quickly drop it. If you attempt to examine his mouth he usually draws back and struggles to get away.

Acute Gastritis is an inflammation of the lining of the stomach which produces severe and continuous vomiting that comes on suddenly. This most likely is caused by ingestion of an irritant or poison. Common stomach irritants include toxic plants, fertilizers, cleaning agents and antifreeze. Aspirin will also produce gastric irritation. Frequently, a cat with an upset stomach vomits shortly after eating. Later, he may stop eating altogether and appear lethargic, sitting with his head hanging over the water bowl.

A cat with impaired liver functions appears weak and lethargic and exhibits loss of appetite and weight. He may also suffer from vomiting and diarrhea, drink excessively, and experience pain in the abdomen.

Signs of right heart failure are less common than those of left-sided failure. As the right heart muscle begins to weaken, pressure backs up in the veins, causing congestive heart failure. The early signs of right-sided heart failure in the cat are lethargy, loss of appetite, shortness of breath and rapid pulse. In late stages you will observe weight loss, enlargement of the liver and spleen, and accumulation of fluid in the abdomen, giving a pot-bellied look.

Anemia can be defined as a deficiency of red blood cells in the circulation. Signs vary considerably, depending upon the cause. Often they are overshadowed by the signs of the acute or chronic illness, of which anemia is but one of the associated symptoms. In general, anemic cats lack appetite, lose weight, sleep a great deal, and show generalized weakness.

Kidney failure causes an increase in frequency of urination. This large urine output must be compensated for by increased fluid intake. A constant supply of clean fresh water should be made available at all times. This step is important in helping the cat adjust to his reduced kidney function. As his renal function continues to deteriorate, he will begin to retain ammonia, nitrogen, acids and other waste products in his bloodstream and tissues (uremic poisoning). Signs of Uremia are apathy and depression, refusal to eat, loss of weight and condition, dry hair-coat, a brownish discoloration to the surface of the tongue, ulcers on the gums and tongue, and an ammonia-like odor to the breath.

An abcess of the Uterus (Pyometra) is a life-threatening disease to queens over 5 years of age that have never been pregnant. A queen with Pyometra refuses to eat, appears depressed and lethargic, usually runs a fever, drinks a great deal and urinates frequently.

Of course there are many instances where your cat not eating is a variable of a behavioral issue rather than an illness. Your cat may develop a preference for a food that is highly palatable such as liver, kidneys, milk, eggs, chicken and then refuse to eat a complete diet.

At times it might become necessary to adjust a cat's diet due to an illness. If he refuses the new diet, the procedure for switching over is as follows: To 80 percent of the original food add 20 percent of the new food, mix together thoroughly and feed the mixture until the cat accepts it. When this is accomplished, increase the amount of new food to 40 percent. Increase the new portions in this manner until the switch is complete.

A very rare eating disorder in cats is Anorexia Nervosa. This is a condition in which the cat refuses to eat, loses weight and begins to starve himself. A deep-seated insecurity or nervous stress usually is at the root of the problem. A veterinary examination is needed in this instance.

References: The Cat Owner's Home Veterinary Handbook by Delbert G. Carlson, D.V.M and James M. Giffin, M.D. - First Edition