Psychopharmacology has become a popular, and sometimes mandatory addition to treatment regimes for canine and feline patients with behavioural problems; however, clients and practitioners should be dissuaded that behavioural drugs are 'quick fixes'. Veterinarians should only prescribe psychotropic medication when they have a specific idea of how the mechanism of action of the drug will affect the target behaviours associated with a specific diagnosis. The diagnosis must be treated rather than non-specific signs. Newer psychotropic medications demonstrate the extent to which truly abnormal behaviours are dysfunctions of neurochemistry; synaptic or cellular metabolism; or genetic encoding and 'learning', or LTP, hence there is a clear role for the interaction of neuropharmacology and behavioural and environmental modification.Future advances in treatment in behavioural medicine will be pharmacological and neurophysiological. As the field of behavioural medicine expands, its paradigm will enlarge to include combination therapy and the implementation of neuropharmacological intervention as a diagnostic tool. At present, the veterinary practitioner can effectively aid many common behavioural problems using extant drugs to treat animals with true behavioural pathology. Rational pharmacological therapy requires complete medical and behavioural histories, requisite laboratory work, complete client understanding and compliance, and an honest and ongoing dialogue between the client and veterinarian that includes frequent follow-ups and re-examinations.