Transcript for United Airlines vows to make changes after puppy dies in overhead bin
and new trouble for united airlines. Just 24 hours after apologizing for what happened to one family's dog on a plane, united now making headlines for yet another mistake, another dog supposed to be brought to Kansas City, but where did that dog end up? Here's ABC's linsey Davis now. Reporter: Tonight, new woes for united after it mistakenly put this dog, irgo, on a 12-hour flight to Japan. Kara swindle was with her family flying from Oregon to Kansas City, but when she got to the cargo facility to pick up her German shepherd, she was given a great Dane instead. He's probably so scared and freaked out. And probably hurting, too, because he doesn't have his medicine now, itselfer. Reporter: She says the airline told her the dogs were accidentally put into the wrong travel kennels. Irgo will now be flying back first class to Kansas tomorrow night. But united's apology for this mistake comes after the tragic death of this puppy, kokito, on a flight from Houston to new York on Monday. He was a member of our family. Reporter: The family and other passengers said the flight attendant demanded the puppy's carry-on case be moved from under the seat in front of them into the overhead bin. We're like, it's a dog, it's a dog, and she's like, it doesn't matter. You still have to put it up there. Reporter: When the plane landed at Laguardia after three hours, the family discovered kokito's body. She took him out and opened the thing and then she got the dog and he was dead. Reporter: Tonight, united says their flight attendant, quote, "Did not hear or understand there was a dog in the bag" and "Did not knowingly place the dog in the overhead bin." And linsey, united making changes so nothing like this happens again? Reporter: That's right, David. They plan to start issuing bright colored bag tags for customers that are traveling with an animal inside the cabin. As soon as the flight attendant sees the tag, they're going to know, there's an animal inside that bag. We've just heard from united, they say they have fully refunded the passengers tickets and pet fees. It's not clear that's going to be enough, David. All right, linsey Davis, thank you.
This transcript has been automatically generated and may not be 100% accurate.