All disease will result in a behavior change; however, not all changes in behavior are caused by disease. In other words, behavior changes can occur by themselves from satisfying emotional needs as well as from learned experiences. In most cases, a change in behavior due to disease is identified through various tests, a physical examination, and a complete history. Once all of the likely rule outs for disease have been eliminated then changes in behavior due to emotional response and learning is usually considered.

As a general rule, the changes in behavior stemming from disease comprise the clear majority (90+%). Some owners over emphasize behavior changes due to the psychological needs of the pet and thus lose their perspective. The human is strongly motivated emotionally and thus projects this trait onto their pets. This is called being anthropomorphic (assigning human values to animals). Asking questions such as; What triggers the behavior?, Is there a pattern in the incidence or frequency of the behavior that is progressive?, Are there any physical symptoms?, will help to separate behavior caused by disease from that that is caused from emotion.

Let's assume we have eliminated all the possible diseases causing changes in behavior. At this point many veterinarians may begin a number of psychoactive drug trials combined with some behavior modification techniques to correct the unwanted behavior. If the behavior problem is arrested as a result of this therapy, then by inductive reasoning, we can conclude that the behavior existed by itself and not from disease. This process of elimination is a time consuming procedure and requires a lot of patience and cooperation.