You got this dog so it would be your responsibility to treat any type of illness that this dog has or gets. I'm up next to Jay on his soapbox, that's what I"ll say.
I wouldn't be at all surprised if the "breeder" puts this puppy down. They can't make any money off him at this point if they treat him. If it is only a urinary tract infection, antibiotics should easily take care of the problem. If you are willing to foot the bill for treatment, then by all means see if you can get him back. There are no guarantees that he will survive at this point, but maybe you can do some good here. If you can't afford treatment, then you may need to re-think having any pet at all. They're living, sentient beings, not throw-away toys. Sorry to imply that that's what your mindset is, I tend to climb on my soapbox on this issue. :-)
Anyway, was the facility where you bought the puppy a licensed breeder, or a side-of-the-road type of place? Backyard breeders? You may have trouble trying to get him back if that's what you decide to do. Hope it works out for you and the pup.