Bile acids are compounds that are made in the liver and stored in the gall bladder and help with digestion of foods. The bile acid test is a very useful test that helps to determine if the liver is working properly. An abnormal bile acid test result indicates there is a problem in the liver, but it does not provide information about the cause, severity, or reversibility of the problem. Further testing is required to investigate the problem.

Antibody titers are sometimes needed to diagnose disease. Antibody titers reflect the level of antibody that the pet has made in response to exposure to a certain infectious organism. The titer is determined by sequentially diluting the serum and testing it against the organism in question. The more dilute the serum when it stops producing a positive reaction, the higher the concentration of antibodies present in the blood. Titers give support to a diagnosis, allowing more targeted treatment and more specific prognostic information, as well as identifying zoonotic disease (diseases transmissible between animals and humans).

An allergy is a state of over-reactivity or hypersensitivity of the immune system to a particular substance called an allergen. Most allergens are proteins from plants, insects, animals, or foods. In dogs, the most common symptom associated with allergies is itchy skin, either localized (in one area) or generalized (all over the body). In other cases, the allergic symptoms affect the digestive system, resulting in vomiting and diarrhea. The symptoms of allergies can be confused with other disorders or occur concurrently with them.