anorexia in dogs

Anorexia (Loss of Appetite) in Dogs

Overview of Anorexia (Loss of Appetite) in Dogs

Anorexia is a term used to describe the situation where a dog 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. 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 an animal less willing to eat.

Alternatively, some animals 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 an animal’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 Anorexia in Dogs

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

Treatment of Anorexia in Dogs

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

Home Care for Anorexia in Dogs

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

In-depth Information on Anorexia in Dogs

There are several causes for anorexia in dogs. 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 dogs include chronic hepatitis (not the same as human hepatitis A, B, or C, and NOT contagious), portosystemic shunt (a defect in the blood circulation through 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 dthose 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).

Other Causes of Anorexia in Dogs

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 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.

Diagnosis In-depth

Treatment In-depth

Treatment of anorexia can be specific or supportive.

Prognosis for Anorexia in Dogs

The prognosis for Anorexia in Dogs depends on the underlying cause.