Drug treatment for almost any behavioral condition is most useful when combined with behavior modification. However, determination of which drug or supplement might be indicated requires a diagnosis. Psychotropic drugs and natural alternatives can be useful for reducing the signs associated with phobic, panic, or chronic anxiety states and to improve trainability, especially in situations in which the pet is too anxious, fearful, or impulsive to learn. Drugs can have a dramatic effect when there is brain pathology or impulse dyscontrol; however, for the most part, they are adjunctive therapy for the treatment of anxiety or arousal that might contribute to a behavior problem and may be necessary for the welfare of the pet.
Evidence-based decision making is a means of providing the best information and treatment options. Treatment should be selected using the evidence combined with the clinician's expertise regarding the patient, client, and problem. In veterinary behavior there are very few drugs that have been adequately tested under rigorous, randomized, controlled trials. To date, the only behavioral drugs licensed for use in North America are clomipramine, fluoxetine, and selegiline for dogs, and the sedative acepromazine. For most other medications used in veterinary behavior, minimal data have been collected and much information is extrapolated from human literature. However, drug metabolism and receptor effects vary between species. This can lead to inaccurate assumptions with respect to dose, duration of effect, contraindications, and adverse effects.
The first choice should be drugs licensed for veterinary use. Not only do these drugs have established efficacy, adverse effects, contraindications, toxicity, pharmacokinetics, and safety profiles, but the technical support available from the manufacturer provides additional expertise, especially if adverse events arise. Other medications have been studied in pets, but evidence for their use and efficacy is often based on smaller trials, case report studies, or anecdotal reports of efficacy (see Behavioral Medicine Introduction: Drug Dosages for Behavioral Therapy in Dogs and Cats a). Therefore, the practitioner should be knowledgeable about indications, recommended dosage, potential adverse effects, and contraindications before dispensing any of these medications. Drugs that are not licensed for use in the species should be dispensed with written guidelines, precautions, and informed consent. In addition, the owners should understand the expected outcomes that might be achieved. Compounding may be required to achieve an appropriate dose and formulation for administration; however, reformulation may alter a drug's pharmacokinetics, safety, efficacy, and stability. Recent studies on the use of transdermal preparations of behavioral drugs such as fluoxetine, amitripyline, and buspirone have found little to no absorption when comparing transdermal to oral dosing.
A physical examination and blood and urine tests should be part of a minimum database prior to dispensing drugs. For many of these drugs, several weeks may be required to achieve therapeutic effect, and prolonged treatment may be necessary to prevent relapse. However, with regular physical examinations and laboratory monitoring there may be few associated risks.
A variety of natural products have been used in the treatment of anxiety. Most of the evidence for efficacy is anecdotal. However, there are a number of studies supporting the efficacy of some of these products for the prevention and treatment of fear and anxiety, including canine dog appeasing pheromone, the feline pheromone Feliway®, l-theanine, α-casozepine, Harmonease® (containing Magnolia officinalis and Phellodendron amurense), as well as perhaps melatonin, aromatherapy, and l-tryptophan.
Last full review/revision March 2012 by Gary Landsberg, BSc, DVM, MRCVS, DACVB, DECVBM-CA