[Rhetts_mama]

I'm one who prefers the bigger size in a yorkie. I would think, depending on what you are having him do as a service dog, that it might actually work to his advantage. Big enough to do some work without getting injured and yet still small enough to be easily portable, not eat huge amounts, etc. It really is hard to guestimate his adult weight at this point though, especially since they all go through growth spurts and he could just be ahead of the curve right now. Most vets and breeders will say you get the best guess of what the adult weight will be if you double the weight at 12 weeks.

Are there specific behaviors that are concerning you with this pup? At 6 weeks, he is just starting to exhibit his personality and still learning a lot from being with his mom and litter mates. Bad habits the home environment is teaching him can be re-trained in most cases with patience and consistency.

Why is he having his second round of shots at only 6 weeks? That is too early for even his first set.

I'm pretty vocal with my opinion that there is no such thing as an accidental breeding- by failing to spay or neuter they were planning on having an accident. I wouldn't be as worried about an AKC registration with a pup who was going to be a service dog, because I would assume from that you have no intention of breeding him & will have him neutered asap and registration isn't a requirement for any service program that I am aware of.

The health guarantee is a concern as is the lack of pre-breeding testing and that may be something you want to use to your advantage in negotiating a better price. If price is a real concern here, you might want to consider a re-homed pet from a rescue or even an older pup from a reputable breeder. If you volunteer with the SPCA, I'm sure they can point you in the direction of a young dog who would love to be your companion animal.