Drug therapy for behavior problems is an option for pets. However, many believe that it should be considered the last option for certain behavior issues, such as separation anxiety, after other methods of treatment have been tried.

Cognitive dysfunction syndrome, also known as senility, can benefit from the use of Selegiline (Anipryl). This drug does have possible side effects, including restlessness and agitation.

Dominance aggression problems with underlying anxiety may be treated with Amitriptylline (Elavil), Fluxetine (Prozac), or Sertraline (Zoloft). Fear-related aggression problems may be treated with the following medications: Amitriptyline (Elavil), Buspirone (BuSpar), Clomipramine (Clomicalm), Fluxetine (Prozac), Propranolol (Inderal), or Imipramine (Trofranil). Territorial or sexual aggression may be treated with Amitriptyline (Elavil), Diazepam (Valium) or, as a last resort, Medroxyprogesterone acetate (Depo-Provera). Possible side effects can occur from the use of these drugs, including sedative effects with Amittiptyline, possible increased interact aggression with Buspirone, gastrointestinal side effects with Clomipramine, rare cases of liver failure in cats with Diazapam, loss of appetite with Fluoetine, salivation and diarrhea with Imipramine, decreased heart rate with Propranalol, and diabetes and breast cancer with Medroxyprogesterone acetate.

Noise phobias and separation anxiety may be treated with Alprazolam (Xanax), Buspirone (BuSpar), Clomipramine (Clomicalm), or Clorazepate (Tranxene). Diazepam (Valium) and Acepromazine may be also be used to treat noise phobias. Amitriptyline (Elavil), Fluxetine (Prozac), Imipramine (Trofranil), and Sertraline (Zoloft) may also be used to treat separation anxiety. These drugs may have the following side effects: drug dependence with Alprazolam, sedative effects with Amitriptyline, possible increased interact aggression with Buspirone, gastrointestinal side effects with Clomipramine, sedation and loss of balance with Clorazepate, rare cases of liver failure in cats with Diazepam, loss of appetite with Fluxetine, and salivation and diarrhea with Imipramine,