The airline expects to complete its review by May 1.
Last week, a 10-year-old, 80-pound German Shepard named Irgo flying on United as cargo ended up in Japan instead of Kansas City. The Verge reports the suspension as temporary while the airline conducts a "thorough and systematic" review of its pets in cargo policy.
While an investigation is conducted into the PetSafe program, the airline has announced that they will no longer accept new reservations for pets in the cargo hold.
United apologized and arranged for the pets to be flown to their proper destinations.
Families and spouses could essentially take a foreign flight to Japan or South Korea and then hop on a plan to the U.S., but it's unclear if service members would be allowed to reroute their orders or accompany them.
Shortly after that episode, a flight from Newark to St. Louis was diverted to OH after it was discovered that a pet had been loaded on the flight by mistake.
Passengers can still carry small pets with them in carry-on luggage, the airline said.
There were at least 18 animal deaths reported on United flights a year ago - more than any USA carrier.
When the plane landed, the dog was dead.
Just a day prior to that incident, United Airlines issued an apology for the death of a passenger's French bulldog after a flight attendant forced the animal to travel in an overhead bin on a three-hour flight from Houston to NY. United later took responsibility for the incident.
Smaller pets can continue to travel in the cabin, and beginning in April, will be identified with brightly-colored bag tags.