Medications commonly used to treat behavioral conditions in dogs and cats include the following:

• Benzodiazepines (BZDs): alprazolam, diazepam, midazolam, clonazepam, and related medications like gabapentin.
• Tricyclic antidepressants (TCAs): amitriptyline, nortriptyline, clomipramine, imipramine, and doxepin.
• Selective serotonin reuptake inhibitors (SSRIs): fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram, and escitalopram.
• Dual serotonin norepinephrine reuptake inhibitors: venlafaxine and duloxetine.
• Dual serotonin 2A agonist/serotonin reuptake inhibitors (SARIs): trazadone and nefazodone.
• Monoamine oxidase inhibitors (MAOIs): selegiline.
• Azapirones: buspirone.
• Centrally acting 2A agonists that may act as hypotensives (decrease in cardiac output and peripheral vascular resistance): clonidine, guanfacine, medetomidine, and dexmedetomidine.
• Local anesthetics (such as lidocaine gel): used before venipuncture, vaccination, or anal sac expression, especially in patients that have experienced procedurerelated fear or pain.

Of those medications, only clomipraminea and fluoxetine (for canine separation anxiety) and selegilineb (for canine cognitive dysfunction syndrome) are approved for dogs in the United States. Controlled studies have demonstrated the efficacy of clomipramine and fluoxetine in combination with behavior modification for treating separation anxiety. ^38–44 Because there are few controlled studies for other medications or indications, most medications are used on an extra-label basis. Extra-label use of pharmaceuticals must be done in the context of diagnosis, a comprehensive treatment plan, a discussion of mechanism of action and expected changes, and full disclosure
that use is nonapproved.

Some medications can be used as needed (e.g., BZDs, 2A agonists, some SARIs, gabapentin) for fears, phobias, and panic. Daily medications may also include TCAs, SSRIs, SARIs, BZDs, 2A agonists, and gabapentin for general fears and anxieties. Onset of action may depend on biotransformation and subsequent regional brain molecular receptor changes; therefore, treatment effects for some medications may not appear for 5–8 wk. Dosage recommendations are available elsewhere. ¹⁴ Keep in mind that when combining medications, dosages may change, and interactions may occur.

Medications should be used only as part of an integrated treatment program. The goals of that approach are to protect the patient and their owners, provide a suitable environment for improvement, and implement appropriate behavior modification, including use of humane, positive-reinforcement tools. Risk assessment is essential for medication use. For example, BZDs can have occasional side effects that render some animals extraordinarily sedated and at risk for self-trauma. Other animals are extraordinarily aroused and also at risk for self-injury. It is impossible to know if a particular animal will experience undesirable effects in advance; therefore, a team approach to treatment, observation, reporting, and recording outcome is essential. Veterinarian and client monitoring should include observation of heart rate, agitation or sedation, profound changes in appetite, vomiting, diarrhea that is not transient, and any new problematic behaviors or behavior changes.

Nutraceuticals and specialized diets are available that may or may not aid in the treatment of behavior problems. Research on nutraceuticals is ongoing and usage recommendations are not evidence-based at this time. 

This Task Force recognizes that there are many alternative therapies used for behavioral problems. As a general rule, such treatments have not been adequately studied to warrant specific recommendations by the Task Force on either their use or benefit at this time. For example, although pheromonal products are commonly used to alter canine and feline behavior, there is no consensus among experts regarding their value, and definitive clinical study evidence of their efficacy is lacking.