8 weeks is too young to be separated from mom to begin with. I will admit, Kaji was shipped to me, he was a year old and we didn't have any problems. BUT, I will NEVER do it again. We've had the opportunity to fly together, and that seemed stressful enough since I was near and he still couldn't be with me (under the seat). I broke to the rules and had him on my lap for most of the flight. But if that was a bit stressful, imagine going in cargo? I think he was peed on by other animals in cargo. His back smelled so bad, but the shredded newspaper wasn't soiled.
In retrospect, I wish I hadn't done it. It just sounds so horrible now.