Two metro Detroit families bought puppies, but both became sick a few days later.

The two families have test results from their veterinarians that say their dogs got sick with parvovirus. They found each other online and realized they both bought dogs from the same person within weeks of each other.

Steve Eldridge received his golden retriever puppy from his wife as a Christmas present on a Sunday in December.  

"Of course, you fall in love instantly," said Eldridge.

Griffin started getting sick his first week home.  He had vomiting and diarrhea.

"My daughter went online, checked his symptoms, and said, we have to go to the vet now," said Eldridge.

Griffin was diagnosed with parvovirus. The veterinarian bills quickly grew out of control.

"They thought that they would be able to treat for $700 to $1,000 and after all was said and done, it ended up closer to $2,000," said Eldridge.

Wendy and Michael Martin bought a boxer puppy on New Year's Day.  

"Once you bring a puppy into your home," said Wendy Martin. "There's just an instant love for puppies."

The Martins brought their dog home on a Sunday.  By Tuesday, they had to take him to the veterinarian.  He too tested positive for parvovirus.

Bo survived too.

"We were very very lucky," said Martin.

The Eldridge and Martin families both bought their dogs from Nicole Robertson in Nashville, Mich.

Local 4 producers, using hidden cameras, paid Robertson a visit inquiring about a puppy for sale.

"I don't offer a warranty or refund. I'm not a breeder, I'm not a pet store, ok?," said Robertson.

Roberston said she does private rescue.    While producers were there, she talked about the problem of parvovirus in puppies.

"Parvo is something that is very prevalent in dogs. I mean, especially in Michigan," said Robertson.

And it is. According to the Michigan Veterinary Specialists, parvovirus is a highly contagious and potentially fatal virus that can affect dogs at any age, but is most common in those under 6 months old.

"Unfortunately, in four and a half years, I've seen parvo," said Robertson.

According to court documents, one case turned fatal. A St. Clair Shores couple sued her in 2008. They bought a toy poodle, that they say died from parvovirus 10 days later.  They won $494.

After some emails and phone calls failed to answer all our questions, we wanted to sit down with Robertson to talk about her experience with parvo.

Ruth Spencer went to her Nashville home.  She declined to do an on-camera interview but told us she offered to take both dogs back.   It was an offer neither family agreed to do.

"Why would we take a sick dying puppy, it would be like taking someone off of life support to transport him to another hospital," said Martin.

"The last thing I was going to do was take that puppy back," said Eldridge.

Robertson said once customers choose to have the dogs treated elsewhere, they take on those expenses.

In the Eldridge's case, she did refund the purchase price of $460, for a dog, she says, could be worth $900 to $1,200.

Robertson has offered to return $205 to the Martins, the price of their vet bills.

Robertson told Local 4 when both families told her their dogs were sick with parvo, she held the dogs from the same litter for a week to make sure they didn't get sick and, she said no other dogs did.

Barry County Animal Control has inspected her home four times since 2009 and did not find any problems.

Is there anything you can do to try and make sure a dog you buy doesn't have parvovirus?  Local 4 spoke to the Department of Agriculture and Rural Development.

"Request a copy of a veterinary examination of that animal, a health certificate or a statement that a veterinarian has examined the animal," said Halstead.

The Eldridges and the Martins did not get a certificate like that, instead they received a puppy health record signed by Robertson.

The advice from these new pet owners is clear, if you're thinking about buying a dog..

"Do your research," said Eldridge.

The Michigan Department of Agriculture and Rural Development no longer has the money to issue licenses or inspections for pet stores, but said anyone selling pets, unless they're a breeder selling their own animals, must follow the state's pet shop laws as guidelines.