omg that's so sad. is the pup ok now?
one time i bought a pup from the kennel, and he got sick after 2 days at my house, and died after 3 weeks treatment from the vet.
actually he already got sick from the kennel, but i didnt know, bcs he looked ok when we got him. i called the kennel and explained. and she asked me to get the new pup from her to replace, and now the new one is living healthy and happily with me.
kennel should have responsibility.. usually they give us some kind of warranty for 1 month (not incl if we change our mind of course, but in case if the pup is sick from the breeder)

i jz feel sorry for the pup.. please give him good treatment until he recovers. and shame on the seller!! really irresponsible!