I posted a while back about pet transport companies, but am now considering flying with my dogs. Does anyone have experience putting their dogs in cargo for a 3-4 hour flight? I have carried on, in the cabin, two of my dogs before, but one of my dogs is too big to carry on. He's only 25 pounds but the limit is 20 pounds and he's too long-limbed to be comfortable in an underseat carrier. He's also 7+ years old - don't know if age makes a difference. He's heart clear and healthy at this time. Any one with experience with this? Thanks.