NEW YORK (CBSNewYork/AP) – United is suspending its PetSafe reservation service, which lets customers ship their pets as cargo.

The announcement comes after the airline mistakenly flew a German shepherd to Japan instead of Kansas and loaded another dog onto the wrong airplane. Both animals were flying in cargo holds.

United says it is reviewing its service, which carries fees of up to several hundred dollars for a medium-size or large dog. It expects the review to be complete by May 1.

Spokesman Charles Hobart said the airline will consult independent experts in pet safety and is not ending the program.

He also said the carrier will give crews more advance warning about the number and type of animals flying in cargo for each flight, and ramp supervisors will be required to oversee the loading and unloading of animals, while another official will have to certify that all the animals were handled properly before the flight takes off.

The suspension does not affect pets flying in cabins, like the French bulldog that died last week after a flight attendant ordered a passenger to put the dog’s carrier in the overhead bin.

In wake of the incident, United announced it will now put brightly colored tags on pet carriers in plane cabins.

The airline carries more animals in cargo than any other U.S. carrier — about 138,000 last year. In 2017, 18 animals died in United’s care, three-fourths of all such deaths on U.S. airlines.

However, United is not the only airline to make mistakes while handling pets. Over the weekend, Delta Air Lines apologized after sending an 8-week-old puppy to the wrong destination.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)