Starting in 2005, through lobbying from HSUS, PETA, the ASPCA and other animal advocacy organizations, The United States Department of Transportation (USDOT) has required all U.S. Commercial airlines that operate scheduled passenger flights to file monthly incident reports.  These reports address the number of animals that died, were lost, or became injured during transport. 

This requirement can be found in section 710 of the 2000 Wendell H. Ford Aviation Investment and Reform Act for the 21st Century (as subsequently codified at Title 49, Section 41721 of the United States Code and Title 14, Section 234.13 of the Code of Federal Regulations)

The Department of Transportation publishes these reports on their website, but they are not easy to find and often burried in the Consumer Reports area of their website.  Below is information on the monthly incident reports.

Please Note:
- According to Jol A. Silversmith of ThirdAmendment.com, "the data for each airline does not necessarily indicate the quality of service that it provides, because the number of animals transported by each airline varies widely.  For example, Continental Airlines, which transports numerous pets, has emphasized that incident reports are filed for less than 0.05% of the pets that it transports.  In contrast, Southwest Airlines does not transport pets (except service animals, as required by law), and no reports have been filed by Southwest to date."

Something else to note, the DOT does not require reports to be filed for all animal incidents (Details can be found in the DOT, 14 CFR Part 234 [Docket No. OST-2005-20331]. In summary reports are NOT required to be filed for incidents involved the following situations:

• Animals that are not kept as a pet in a family household in the United States
• Animals that are carried on all-cargo or unscheduled flights
• Animals that are carried on a flight operated by a foreign airline, even if the flight carried the code of a U.S. Carrier

According to Jol A. Silversmith, he received a letter from the DOT elaborating that "it also interprets the reporting requirements not to apply to "escapes [which] last only a few minutes or a few hours."  

Additional Reading:
"The Dog That Did Nothing. The Curious Incident of DOT's Animal Incident Reporting Requirements" by Jol A. Silversmith

United States of America Department of Transportation Office of Aviation Enforcement & Proceedings, Aviation Consumer Protection Division.
         2009            2008             2007            2006            2005
 
 
Airline - Pet Incident Report 
(Only United States Based carriers are required to report incidents)

Below is a list of all incidents involving the loss, injury, or death of a pet during air travel or shipping.
Information current as of April 2009.