One of Delta's latest changes came in December, when it stopped accepting snub-nosed dogs or cats as checked items. Delta already had banned American, English and French bulldogs from flying. That came after a sharp increase in the number of animals that ran into trouble on Delta flights, particularly bulldogs, which are susceptible to respiratory problems.
In most cases, pet deaths are not caused by mishandling but because the pets run into health issues in the cargo hold environment, Delta said. The Humane Society of the United States recommends not transporting pets by air "unless absolutely necessary" because of the risks.