I have begun to look at possible flights for the pups who are leaving via air - please keep in mind that with the exception of Continiental Airlines, it must be cooler than 85F in both Minneapolis as well as in the destination city in order for DELTA to accept pups. Delta/Northwest is the airline with the most flights from MSP. I generally use www.kayak.com to see what is available and then go from there. Many airlines no longer accept pets (USAir for example.)
I am approximately 1.5 hours east of the airport and the pup needs to be checked in two hours in advance so it is important to factor those times in when looking at flights.
