Q: I bought a puppy from a breeder in California. I recently found out my puppy has an hereditary condition.

A: First, give the breeder notice of the defect, with a written veterinarian certification that states within one year after the purchaser has taken physical possession of the dog after the sale by a breeder, that the dog has a congenital or hereditary condition that adversely affects the health of the dog, or that requires, or is likely in the future to require, hospitalization or non-elective surgical procedures, and ask for one of these remedies:

"(1) Return the dog to the breeder for a refund of the purchase price, plus sales tax, and reimbursement for reasonable veterinary fees for diagnosis and treating the dog in an amount not to exceed the original purchase price of the dog, including sales tax.

(2) Exchange the dog for a dog of the purchaser's choice of equivalent value, providing a replacement dog is available, and receive reimbursement for reasonable veterinary fees for diagnosis and treating the dog in an amount not to exceed the original purchase price of the dog, plus sales tax on the original purchase price of the dog.

(3) Retain the dog, and receive reimbursement for reasonable veterinary fees for diagnosis and treating the dog in an amount not to exceed 150 percent of the original purchase price of the dog, plus sales tax."

codes.findlaw.com/ca/health-and-safety-code/hsc-sect-122070.html

In order to be entitled to those remedies, the person from whom you purchased the dog must qualify as a breeder. The Polanco-Lockyer Pet Breeder Warranty Act defines a breeder as a person, firm, partnership, corporation, or other association that has sold, transferred, or given away all or part of three or more litters or 20 or more dogs during the preceding 12 months that were bred and reared on the premises of the person, firm, partnership, corporation, or other association. codes.findlaw.com/ca/health-and-safety-code/hsc-sect-122045.html

If the breeder refuses, you can sue in Small Claims court. An attorney can help you prepare the necessary paperwork and get the suit filed and served if you are uncomfortable doing this yourself.