anorexia in cats

Anorexia (Loss of Appetite) in Cats

Anorexia is a term used to describe the situation where a cat loses his appetite and does not want to eat or is unable to eat. Appetite is psychological, dependent on memory and association, as compared with hunger, which is physiologically aroused by the body’s need for food.

There are many causes of anorexia in cats. Often, a loss of appetite is the first indication of illness. Diseases of the digestive system (esophagus, stomach, intestine, liver, pancreas), the kidneys, the blood, the eyes, mouth, nose, and throat, the skin, the brain, and many other organs in the body can cause a loss of appetite. Pain of any cause can also make a cat less willing to eat.

Alternatively, cats will occasionally refuse food for reasons that are much less serious, such as dislike for a new food, or behavioral reasons (new home, new animal or new person in household, etc.)

Regardless of cause, loss of appetite can have a serious impact on your cat’s health if it lasts 24 hours or more. Very young animals (less than 6 months of age) are particularly prone to the problems brought on by loss of appetite.

Diagnosis of Loss of Feline Appetite

Because of the numerous causes of anorexia, your veterinarian will recommend certain procedures to pinpoint the underlying problem. These may include:

Treatment for Feline Anorexia

Treatments are of two kinds: “specific” and “supportive.”

Supportive treatments do not reverse the problem that led to the loss of appetite. They simply help “carry” the animal through the most difficult part of the illness.

Home Care for Anorexia in Cats

Home care is concerned with observing your cat for possible reasons for his anorexia and helping him to eat.

In-depth Information on Anorexia in Cats

The reasons for which animals refuse to eat may be grouped into two major categories:

Psychological and Medical

Gastrointestinal Diseases

If the esophagus (tube in the throat that connects the mouth to the stomach), the stomach, or the intestine, is inflamed (irritated) by disease, eating can become uncomfortable or nauseating, resulting in anorexia. Diseases that can cause this kind of irritation include parasites (worms), viruses such as parvovirus and coronavirus, other infections such as bacterial and fungal infections, ulcers, food allergy, inflammation of unknown cause (“idiopathic”), and certain infiltrative cancers. A complete or partial blockage of the digestive tract can also cause unwillingness to eat. This most often occurs with foreign bodies (objects that are swallowed and become stuck partway down the digestive tract) and cancers of either a benign or malignant nature.

Gastrointestinal diseases in general often will also cause increased salivation, vomiting, diarrhea, and sometimes (particularly when more severe) lethargy and sluggishness.

Diseases of the Liver

The liver filters many of the body’s waste products and toxins from the bloodstream, so that accumulation of these substances as a result of inadequate liver function affects the brain, and blunts the sense of hunger. Common diseases of the liver in cats include chronic hepatitis (not the same as human hepatitis A, B, or C, and NOT contagious), hepatic lipidosis (fatty deposits in the liver), cirrhosis (severe scarring of the liver), liver cancer, and adverse reaction to certain drugs (e.g. carprofen, trimethoprim-sulfa, others).

Liver diseases in general often will also cause increased salivation, vomiting, and lethargy and sluggishness.

Diseases of the Pancreas

The pancreas secretes many of the digestive juices that dissolve food into tiny particles the intestine can absorb. If inflamed (“pancreatitis”), the pancreas releases some of those powerful dissolving substances into the internal organs rather than on food in the intestine. These corrosive juices may severely inflame and erode the pancreas itself and other surrounding tissues, a painful process that often makes an animal completely unwilling to eat and frequently also causes vomiting and lethargy. Another disease of the pancreas that can cause loss of appetite is pancreatic cancer.

Diseases of the Urinary Tract

Anorexia is a hallmark of kidney disease. There may be both a loss of appetite and discomfort caused by ulcers in the mouth and stomach associated with uremia (accumulation of waste products in the blood stream). Your pet’s consumption of water may be the same or even greater than usual. This is an effort to make up for the tremendous amount of fluid lost by the sick kidneys through the urine. Also, vomiting and listlessness are common symptoms that occur along with loss of appetite in kidney disease. Not all types of urinary disease affect the appetite, however. For instance, most cases of bacterial cystitis (bladder infection) do not affect the appetite.

Diseases of the Blood

Generally, diseases of the blood that lead to loss of appetite also cause lethargy and sluggishness, and possibly signs of weakness such as intermittent collapse. Blood disorders causing loss of appetite include severe anemia of different causes (immune-mediated hemolytic anemia, leukemia-related anemia, blood loss due to ulcers of the stomach or rat bait poisoning), cancer of the blood (leukemia), and polycythemia (excessive red blood cells – the opposite of anemia).

Diseases of the Eyes, Mouth, Nose, and Throat

These can cause unwillingness to eat as a result of pain in the mouth during chewing (dental disease, foreign object caught in the mouth or throat), inability to smell the food, which is essential in animals for recognition and acceptance of food (nasal infections or tumors), or pain or discomfort of the eyes (conjunctivitis, uveitis, glaucoma).


Essentially any disease process, when severe enough, can cause an animal to stop eating. Loss of appetite is one of the first and most common symptoms of “not feeling well” in animals. Don’t hesitate to take your pet to the veterinarian when he is anorexic.

A prolonged inability or unwillingness to eat may be a sign of serious illness in your pet.

If your pet refuses to eat, watch for any of the following: NOTE The presence of these in conjunction with anorexia, warrants an immediate consultation with your veterinarian, regardless of how long the loss of appetite has been present.

Medical causes of appetite loss usually are more serious than psychological causes because they mean that a disease has progressed to the point that the animal is either unwilling or unable to eat. Therefore, the animal’s challenges are twofold: first, to fight the disease itself, and second, to do so without the benefit of nutrients that eating provides.

Diagnosis In-depth for Anorexia in Cats

Treatment In-depth for Anorexia in Cats

Treatment of anorexia can be specific or supportive.

Specific treatments: Specific treatments are those that deal with the underlying cause. That is, they either slow down or eliminate the problem that caused the anorexia in the first place.

Of course, specific treatment is ideal because it deals with the loss of appetite at its source by treating the underlying disease. However, specific treatment requires an exact diagnosis, meaning that in some cases many tests may need to be performed in order to precisely identify the underlying disease.

Supportive treatments: Supportive treatments are those that help sustain an animal that is debilitated as a result of not eating. Supportive treatments do not reverse the problem that led to the loss of appetite. They simply help “carry” the animal through the most difficult part of the illness.

On the other hand, supportive treatments can be given in almost all cases and are most useful in the four following situations:

Supportive treatment is often simpler than specific treatment, but it also carries the risk of not addressing the underlying problem. Commonly used supportive treatments include:

Capromorelin Oral Solution, commonly known as Entyce®, is used as an appetite stimulant in dogs and cats. It is FDA approved for use in dogs only but has been successfully used in cats.

Capromorelin belongs to the selective ghrelin receptor agonist group of drug compounds that finds to receptors and induces the signal in the hypothalamus of the brain to cause appetite stimulation. Capromorelin has a second benefit as it binds to the growth hormone secretagogue receptor that has the therapeutic value in the elderly who have less muscle mass, which can lead to weakness. Human studies have not only found an increased appetite and weight gain, but also improved balance and coordination. ****Capromorelin is can be used in combination with other anti-vomiting or acid-reducing drugs.

Prognosis for Anorexia in Cats

The prognosis for Anorexia in cats depends on the underlying cause for the loss of appetite and the cats’ response to treatment.

We hope this article about anorexia in cats gives you more information about the common causes of inappetence, diagnostic tests to determine the underlying cause and treatment options for feline anorexia.