The overhaul of its rules were prompted in part by the highly publicized death of one dog, and several mix-ups of other pets, in March.
Under the new policy that takes effect June 18, United will prohibit short-nosed dog breeds including pugs and bulldogs, as well as “strong-jawed” breeds such as American pit bull terriers. The rules will also affect large dog breeds including a variety of mastiffs.
Passengers will still be allowed to bring small pets into the main cabin, however.
United said it is working with the animal welfare organization American Humane to improve its pet travel policies.
The full list of pets restricted by United are:
The airline halted transporting pets in March after one dog died in an overhead bin and several other dogs were loaded onto the wrong planes.
In the case of the dog that died, the family that owned a French bulldog claimed it followed the airline’s policy of placing the dog in a carrier beneath the seat. But a flight attendant told them the case needed to be placed in the overhead bin.