I purchased a puppy from two people under the assumption that he was healthy, which he WAS NOT. I had to take the puppy to my vet the very next morning and the dr. said this is something that did not occur over night, he has had this sickness for a while, because it was so progressed. I have tried to reason with the seller and all she does is tell me lie after lie after lie, I want my money back plus the 4,000$ I have spent caring for the dog! Can I sue them for this even though I signed her contract? I did sign it under the assumption I was buying a healthy animal

You just bought the pup, right, and the vet stated the pup has been ill for some time. There is your case. A letter from this vet stating the pup has been previously ill. I would definitely pursue this in court. Was she a recognized breeder?

NO! She has many many adds online,they ALL say the same thing. She claimed it was her mother-in-law's dog she was selling, that she was doing her MIL a favor.

Also, I bought him Noevember 24th of last year, this whole time I have been trying to resolve this problem with her and her husband and they could care less, do you think it is to late to sue?