Did you have any puppies in your home that became ill or died of parvo virus 6 months prior to your bringing this one into your home? Did you mention this to the breeder? If not, you have the basis of a lawsuit there. What the breeder did in cancelling her reimbursement check to you is a felony. The breeder is less than ethical, which is usually the case and which is why I never advise people to buy a puppy from someone they don't know. That puppy was sick when you bought it. That is a fact supported by your discussion with the breeder when you purchased the pup, and by your veterinarian when he examined the pup the following morning. A responsible breeder always guarantees the health of a puppy. A puppy should never have any health issues when you purchase it. That was your mistake for believing this person to start with. But, for her to suggest the parvo virus was picked up while under your care is outrageous. Do you have any friends that are lawyers? A simple phone call to her from your lawyer might do the trick. If not, I suggest you sue her in small claims court. Speak with your veterinarian about being there to testify for you. Hold onto the cancelled check when it is returned to you. THAT alone is the strongest evidence in this case. Sue her for the cost of the pup, the vet bills, and the returned check fee. Make sure you bring all of this paperwork to court to support your claims. Unless there is something missing from your story, she will be found responsible. A judge will not look too kindly on her when he sees that cancelled check.