An acclimation certificate is used to allow airlines to ship dogs and cats when the airline cannot guarantee compliance with animal welfare regulations, specifically the minimum temperature allowed by the regulations. Veterinarians may advise clients not to ship animals with transporters or airlines that cannot guarantee compliance with animal welfare regulations. In accordance with the Code of Federal Regulations 9 CFR section 3, regardless of the temperature range suggested by the owner/authorized agent or veterinarian, ambient temperatures listed in the acclimation certificate cannot be higher than 85 F for more than four consecutive hours while in animal holding areas of airport terminals or for more than 45 minutes while transferring the animal between the aircraft and the animal holding area. Carriers or intermediate handlers whose facilities fail to meet the minimum temperature allowed by the standards may accept for transportation or transport, in commerce, any live animal if the consignor furnishes to the carrier or intermediate handler a certificate executed by an accredited veterinarian stating that such live animal is acclimated to air temperatures lower than those prescribed in the CFR (45 degrees F).

Acclimation certificates issued in accordance with 9 CFR section 3 no more than 10 days prior to delivery of the animal(s) for transportation should only be provided as a statement attached to a Certificate of Veterinary Inspection and shall include at least the following information: (1) Name and address of consignor; (2) The number and identification of animals in the shipment; (3) A certifying statement; (4) The signature of the USDA accredited veterinarian, assigned accreditation number, and date. Veterinarians who sign Certificates of Acclimation for the transportation of pet animals that may be exposed to adverse temperatures, should word their certifying statement as follows:

"The animal(s) in this shipment appear healthy for transport but need(s) to be maintained at a range of ambient temperatures to which the animal(s) has/have been acclimated, as determined in consultation with the owner/authorized agent to be no lower than (W degrees) F for (X) minutes and no higher than (Y degrees) F (not to exceed 85 F) for no longer than (Z) minutes."