Sedation of any kind is bad for your pet
Reports, and articles from as far back as June 1997 from the Animal Transport Association (ATA), the American Veterinary Medical Association (AVMA), and the American Humane Association (AHA) contain excellent advice why animals should never be tranquillized for air travel.
Version date: June 29, 2014
As far as the international transportation of dogs and cats is concerned, the IATA Live Animals Regulations states that "sedation of animals, except under certain conditions and carried out under veterinary direction, is not recommended." This is because most, if not all, commonly used tranquillizing drugs have the effect of lowering the blood pressure - something which also occurs naturally at high altitudes. The air pressure of an aircraft in flight is set at the equivalent of approximately 8,000 feet. The combination of altitude and drugs is potentially fatal in stressed animals.
For any pet, air travel is a new experience. PetFlight accepts your pet, to be held for at least 24 hours registered Veterinary Hospital of our choice (and agreed by Transport Canada, and the individual airlines). From the moment your pet is picked up from your home, everything proceeds in a calm ordered fashion with plenty of time. Your pet will be in a larger cage or run than the travel kennel, the staff at the veterinary hospital have been used to the pre-flight process for years, which we worked out with them from day one. On the flight day, they are picked up again, with plenty of time to spare, and taken to the airline, where we see them through the various check in processes. Pets are curious little creatures, and respond to calm of others.
All pets are placed in a pressurized, heated, and ventilated cargo compartment located just below the passenger compartments. For flight, the lights are dimmed, mimicking night, so pets will naturally sleep.
AVMA pointed out that increased altitude can create respiratory and cardiovascular problems for dogs and cats that are sedated in any manner. Brachiocephalic dogs and cats are especially effected. When deaths occur, they often result from the use of sedation. These facts are often not clearly pointed by vets to pet owners.