Consider a Tranquilizer
As anxious as you might get while traveling, pets are sometimes more so, especially when flying. Being placed in a crate and stowed with a lot of other equally anxious animals makes traveling rough for your pet. To help make the ride a little smoother, consider giving your pet tranquilizers.
You won't want to share any of your own prescription tranquilizers. While some sedatives like diazepam (Valium) work on both humans and animals, the dosage will be different for your pet. Instead, ask your vet for a prescription when you take your pet for its pre-flight physical.
The American Humane Association suggests you skip tranquilizers and sedatives for your pet altogether when traveling by air. Sedated animals may have trouble breathing at higher altitudes, especially short-faced dogs and cats prone to respiratory distress [source: AHA]. Your pet may be much more anxious during the trip, but the likelihood of respiratory distress may decrease.
If you do opt to sedate your pet, be wary of medications sold online, and completely avoid any online pet pharmaceutical retailer that doesn't require a prescription. These drugs are likely counterfeit and may contain none of the active ingredient -- or far too much.