Oriole, a black-and-white guinea pig from North Carolina, never made it to Portland, Ore., with his owner. Oriole succumbed to pneumonia last June during his connection in Atlanta for a Delta flight. A necropsy performed by veterinarians at the University of Georgia found that inflammation in the rodent’s lungs “played a contributory role in his death.”

Oriole was not alone. U.S. airlines reported 17 animal fatalities and 26 injuries in 2014, according to full-year data released on Tuesday by the Department of Transportation. The agency compiles an extensive array of airline operating data such as flight delays, customer complaints, mishandled luggage, and animal deaths/injuries each month in its Consumer Air Travel Report.

United Airlines reported the most deaths and injuries, five and 13 respectively, followed by Alaska Airlines, which had three animal deaths and 11 injuries. Most of the injuries involved dogs and cats bloodied and hurt as they tried to escape from their cages, and many of the fatality reports involved animals that managed to escape from transport cages and were hit by vehicles at airports. Other major causes of death were underlying health conditions aggravated by the stress of travel.

From 2010 to 2013, Delta Air Lines reported the greatest number of incidents of animals that died, were injured, or lost during travel, followed closely by Alaska, the Seattle Timesre ported in September. Some airlines do not accept short- nosed or snub-nosed dogs such as pugs and English bulldogs because the stress of flight is particularly acute for those breeds. Alaska told the newspaper that it is reviewing its policies for those animals.

This article was written by Justin Bachman from Bloomberg and was legally licensed through the NewsCred publisher network.

Photo Credit: A dog named "Buddy" waits in its carrier with its family at Ronald Reagan National Airport. Larry Downing / Reuters