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.
- Physical examination including buccal exam (evaluating the gums), auscultation (listening with a stethoscope), palpation of the abdomen (feeling the size and shape of organs in the belly), and taking the temperature and weight.
- Complete blood panel and urinalysis (urine test) to screen for certain diseases of the internal organs. Many internal disorders are first identified with these tests. In particular, diseases of the liver, pancreas, urinary system, and blood are often first detected with these tests. Further and more specific tests may then be appropriate. For example, signs of liver disease may be seen on the blood test; then, an additional blood test (“bile acids”), and/or abdominal ultrasound may be recommended in order to better define the type of liver disease present. Ultimately with liver disease, a liver biopsy (tissue sample of the liver, usually obtained when the animal is sedated or under anesthesia) is often necessary to determine the exact type of problem present.
- X-rays of the chest and the abdomen. X-rays provide an image of the bones, of course, but also of the outlines of the internal organs, and can be extremely useful for detecting changes in the shape, size, or position of the organs, which helps to pinpoint the source of the disease. Unfortunately, important structures can sometimes blend together on X-rays (e.g. tumors blending into the background of normal organs, or foreign objects having the same “opacity,” or shade of grey, as the normal tissues) and therefore can be invisible on the X-ray. In general, X-rays are an excellent “screening test,” but they do not detect all internal problems, and additional procedures such as ultrasound, barium (dye) swallowing for specialized X-rays, or even exploratory surgery are sometimes necessary to diagnose the problem.
- Fecal examination (microscopic evaluation of the stool, looking for parasites). Your veterinarian may want a stool specimen from your pet for such tests. If your pet has defecated in the past 12 hours, you should bring a sample of the stool with you in a sealed container (e.g. Ziplock® bag) when you go to your veterinarian’s office, in case it is needed for laboratory analysis.
- Ultrasound. As mentioned above, ultrasound and X-rays often go hand-in-hand because ultrasound shows a motion picture of the organs while they are functioning (while X-rays are a static image) and ultrasound allows you to see inside certain organs where X-rays only show their outline. Since performing the ultrasound and interpreting its results require specialized skills and equipment, many veterinarians refer animals needing an ultrasound exam to a specialty veterinary hospital. However, some clinics have ultrasound facilities on-site, and others use the services of traveling specialists who come to the clinic and perform the ultrasound there.
- Endoscopy. An endoscope is a long, flexible tube with a tiny (pinhead-size) camera and a pinch-biopsy instrument at its tip. Depending on symptoms, an endoscope is used for looking either at the inner lining of the throat, stomach, and intestine; or at the respiratory passages (nose, throat, and lungs) while an animal is under anesthesia. Small samples of these areas can be taken and then analyzed in the laboratory to try to determine the nature of the respiratory or intestinal disease. Many diseases of the digestive system and of the respiratory system are difficult to detect simply with blood and urine tests, X-rays, and ultrasound. That is, the diseases tend to be present and may be causing severe symptoms, and yet the blood and urine tests, X-rays, and ultrasound exam are “suggestive” of digestive or respiratory disease without specifically pinpointing exactly which disease is present. It is under these circumstances that anesthesia and endoscopy may be considered, and often a specialist performs it.
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.