United Airlines will no longer allow certain breeds of pets to travel in the cargo hold on its planes. Starting June 18, the airline will ban certain breeds—including Boston terriers, bulldogs, boxers, pugs, and Pekingese dogs—“out of concern for higher adverse-health risks,” the airline said. Studies have shown dogs with short noses are more likely to have health problems on planes. Persian and Himalayan cats will also be banned from the cargo hold. The airline said small pets will still be allowed in the cabin as long as their carrier fits under the seat. In addition, United will not transport pets to Las Vegas, Palm Springs, Phoenix, and Tucson, Arizona, in the summer months “because of the extreme heat in those destinations during summer months.” A 10-month-old French bulldog died on a United Airlines flight this winter after an attendant ordered the pet’s owner to put the dog in an overhead bin.