Xanax is a benzodiazepine given to dogs to reduce fear, excitability or worry in a dog. The ASPCA states that when given to the dog at least one hour before the frightening event, Xanax increases the chemical activity that blocks the fear network activation in the brain.
According to the ASPCA, the unstable behavior of a dog due to anxiety decreases substantially with low doses of Xanax, and the dog exhibits normal behavior at moderate dosage. Dogs are also likely to show more friendly and interactive behavior with a moderate dose of Xanax. High doses of Xanax affect dogs in the same manner as drunkenness because benzodiazepines affect some of the same parts of the brain as alcohol.