Veterinarians must have an understanding of the behavior and development of the species, the principles of learning, and the signs of fear and anxiety in order to differentiate normal behavior from abnormal behavior and behavioral pathology. When presented with an animal with abnormal behavior, the first step is to rule out any medical problems that might be causing or contributing to the behavioral signs. In addition, while it is common to consider the effects of disease on behavior, stress can cause alterations in behavioral, physiologic, and immune responses, which can have variable effects on health and behavior with increasing chronicity. Stress has been shown to lead to alterations in the hypothalamic-pituitary axis and levels of dopamine, serotonin, norepinephrine, and prolactin. In animals, stress can cause or contribute to GI disorders (including anorexia in cats), feline interstitial cystitis, dermatologic conditions, and behavioral disorders such as compulsive disorders, exaggerated fear responses, psychogenic polydipsia and polyphagia, and sleep disorders.

Diagnosis of any behavioral problem requires the identification of all behavioral and medical signs, history taking, a physical and neurologic examination, and any diagnostic tests indicated to rule out underlying medical conditions that might cause or contribute to the signs (see Behavioral Medicine Introduction: Medical Causes of Behavioral Signs).

Table 2
PrintOpen table in new window
Medical Causes of Behavioral Signs Medical Condition Behavioral Signs Central neurologic disorders, particularly if affecting the forebrain, limbic, temporal, or hypothalamic areas Altered awareness, altered response to stimuli, loss of learned behaviors (eg, housesoiling), disorientation, confusion, altered activity levels, temporal disorientation, vocalization, change in temperament (fear, anxiety), ingestive signs Partial seizures (temporal lobe epilepsy) Air snapping, circling, spinning, tail mutilation, chomping, staring, alterations in temperament (eg, intermittent states of fear or aggression), repetitive behaviors, hyperesthesia Sensory dysfunction Altered response to stimuli, confusion, disorientation, irritability, aggression, vocalization, housesoiling Endocrine dysfunction (eg, hyper- or hypothyroidism, hyper- or hypoadrenocorticism, insulinoma, diabetes, functional testicular or adrenal tumors) Altered emotional state, irritability, lethargy, decreased response to stimuli, anxiety, housesoiling or marking, night waking, panting, decreased or increased activity, ingestive signs, aggression, mounting Metabolic disorders (eg, hepatic, renal) Multiple signs related to organ affected Pain Altered response to stimuli (eg, decreased activity, restlessness, vocalization, housesoiling, aggression, irritability, self-trauma) Peripheral neuropathy Self-mutilation, irritability, aggression, circling, hyperesthesia Gastrointestinal disorders Licking, polyphagia, pica, coprophagia, housesoiling (fecal), tongue rolling, windsucking Urogenital disorders Housesoiling (urine), polydipsia Dermatologic disorders Psychogenic alopecia (cats), acral lick dermatitis (dogs), nail biting, hyperesthesia, other self-trauma (chewing, biting, sucking, scratching)

If there is no underlying medical cause for the behavioral signs, then a good behavioral history is taken, including the following items: 1) sex, breed, and age of animal (breed predispositions); 2) age at onset of condition or complaint; 3) duration of condition or complaint; 4) description of actual behavior; 5) frequency of condition or behavior (hourly, daily, weekly, monthly); 6) duration of average bout (seconds, minutes, hours); 7) range of duration of bouts; 8) any changes in pattern, frequency, intensity, and duration of bouts; 9) any corrective measures tried and the response, if any; 10) any activities that stop the behavior (eg, animal collapses); 11) 24-hr schedule of animal and owner, as well as any day-to-day variability; 12) environment and housing; 13) animal's familial history; 14) anything else that the owner thinks is relevant. In farm animals, questions should be framed within the context of the problem so that housing, management, group or herd behavior, production, and perhaps reproduction are addressed.

For each behavior problem, the ABC should be considered, ie, what precedes that behavior (antecedent), the description of the problem (behavior), and what happens immediately following the behavior (consequences). With maturity and learning, the animal's response to a stimulus may be modified; thus, the initial events may be just as important to evaluate as the more recent events.

History might be collected in part by having the owner complete a history questionnaire prior to the visit. However, to reach a diagnosis, determine the prognosis, and develop a practical treatment plan, further interactive questioning and discussion with those who are responsible for the animal's care, housing, and training are required. Having the owners bring videotapes or movie clips of the behaviors can further help to meet diagnostic criteria and provide insight as to the prognosis and how the problem might be managed or improved.

Additional information that might impact the diagnosis, prognosis, or treatment plan might be gained during the visit by observation of the pet and how it interacts with the owners. Assessment might include how the animal responds to other animals and people, sounds, a child-like doll, or handling, including the physical examination, petting, or the application of products such as a head halter, muzzle, or body harness. How the pet responds to commands and which treats or toys are most likely to motivate the pet might also be assessed during the visit.

Last full review/revision March 2012 by Gary Landsberg, BSc, DVM, MRCVS, DACVB, DECVBM-CA