United Airlines accounted for a third of animal deaths on U.S. flights in last 5 years
The death of a giant rabbit on a United Airlines flight from London to Chicago focused the spotlight again on the carrier that has struggled with more than one-third of U.S. animal deaths aboard passenger flights during the last five years.

United had 53 animals die on its flights from January 2012 through February 2017, the most recent month available, according to the Transportation Department's Air Travel Consumer Report. That compared with a total of 136 animals that died on all flights of airlines.

In a statement, United said it was saddened by news of the death of Simon, a 3-foot Continental Giant rabbit, on the flight to Chicago's O'Hare International Airport.

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"The safety and well-being of all the animals that travel with us is of the utmost importance to United Airlines and our PetSafe team," United said in the statement. "We have been in contact with our customer and have offered assistance. We are reviewing this matter."

The rabbit's breeder, Annette Edwards, said the animal had an exam three hours before the flight and was fit as a fiddle.

The rabbit incident came after United was under scrutiny for dragging a passenger off a flight April 9 at O'Hare to make way for a crew member. The airline was also criticized for preventing two girls from boarding a flight from Denver to Minneapolis while wearing leggings considered inappropriate for using guess passes given to employees and their relatives.

Onboard animal deaths don't necessarily mean an airline was negligent, as revealed in summaries of department investigations.

Among the four deaths on United flights in January, a Jan. 28 incident involving Hope, a 9-year-old cat, was suspected as heart failure, according to the department. Rocco, a dog, died on a flight Jan. 21 from a cardiac abnormality due to congenital heart disease, according to the medical exam. Two geckos were found dead upon arriving at Raleigh-Durham airport on Jan. 12, but no medical exam was performed.

The department requires passenger airlines to report any deaths, injuries or lost animals from flights with at least 60 seats.