Most vets will let you bring the dog in ASAP and worry about the money later. Get the pup to a vet tomorrow. Probably ate a bad mouse or something. Did you get this puppy from a pet store or a breeder? This is the reason you buy from a good breeder and pay the big bucks for a pet. Everything is documented and all shots, immunizations, etc are done before the pup leaves the breeder and most good breeders will make you sign paperwork to the effect that if you will give the pet a proper home and all the care it needs. Moral of the story, don't buy puppies from petco or walmart or petsmart or some dude on the corner or a "friendly" neighbor....they often come from puppy mills and are not well cared for or well bred from the beginning. But that being said, get the pup to a vet tomorrow.