SAN FRANCISCO (CBS SF) — If you buy a dog from a breeder in California, you may have rights if the dog becomes sick in the first 15-days.

Kathy Nixon says Copper, her 10-week-old Yorkie Maltese-mix was dead within 6 days of bringing him home.

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“Very upsetting to see my children go through this,” Nixon said.

According to her veterinarian, Copper died of parvo virus.

“The vet told me as sick as he was, he had to have been sold that way,” Nixon said.

But, she says the Craigslist seller refused to cover the nearly $900 vet bill.

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“She said it wasn’t her problem.”

Attorney Jacqueline Siemens says if you buy a dog from a breeder, which is defined in California as someone who sells at least 20-puppies, or three litters in a year, you have rights if the dog becomes sick in the first 15-days.

Siemens says if that happens, the dog can be returned for a refund, and the vet bills get covered up to the cost of the dog’s purchase price.  The dog can be exchanged, with the vet bills covered up to the cost of the dog’s purchase price.  The new owners can also keep the dog, and get the vet bills covered up to 1.5-times the dog’s purchase price.

But, proof of the illness is required.

The seller who sold Copper on Craigslist says she doesn’t sell enough dogs to be considered a breeder in California.

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As for Kathy, she says Copper will be her last Craigslist puppy.  Her veterinarian recommended she wait three years before getting another dog, to make sure her home is parvo-free.