
I went to the USA to mate my bitch Dec 2010, and at the same time was helping with the procedures for my friend to Import a puppy by the same sire who was then 5 months old.
USA is a country where the entry rules are the same as for EU, except instead of a PET Passport a Certificate is used, which can be changed to a Pet passport when you get here.
The most important thing is to make sure th pups is implanted with an ISO microchip, otherwise you will also need to buy a scanner that reads that chip and the Americans use different chips that aren't necessarily able to be read her.
The breeder had to find a vet that would used or would buy 1 ISO chip.
The Rabies vaccine licensing is normally not before 3 months of age. So ISO chip, Rabies vaccs at 3 months and pup can travel 3 weeks later. In USA the puppy vaccination course rarely is finished before about 16 - 20 weeks, they separate various items more. I am not sure if any vaccinations are actually required for travel other than Rabies, but I would prefer they were done.
Remember that people fly with their pets regularly in the USA and Europe I found loads of dogs at the Airport at JFK, and Brussels, they only wanted to check the PETS documentation, no vaccination cert was checked even though I had copies of all my girls vaccination records, ditto for the ferry, chip to be scanned document checked re timing to anti parasitic treatment (worried me a lot due to difference in time zones with just the 24 - 48 hour window, unlikely to be so difficult as you have up to 24 - 120 hours now).
I would not rely on the US vet having a clue though some will, but you may find that the Vet isn't an authorised person (my friends breeder had to take the pup to the person who was at JFK who counter stamped what the vet did re tick and tapeworm treatment and timings (though it's only tapeworm now).
There is no blood test requirement into any EU country since 1st January for dogs from other EU countries and USA, Australia and a few other countries.
I would get the breeder to get the crate to use as pups bed, and take them to airport in it, you don't want to be running around trying to boy one, whilst at the airport with a pup in your arms or leave a pup in a car in the car park. The breeder bought the crate on-line, cheaper than they re here, and my friend obviously paid her for it.
Oh remeber the US write dates differently so make sure they make it clear on documents by writing month in words or making sure the right boxes are used for day month and year.