SAN FRANCISCO (KCBS)— We’ve worked with Dr. Jennifer Scarlett from the San Francisco SPCA long enough to know how dangerous K-9 parvovirus is due to its highly contagious nature.

Unvaccinated, under-vaccinated dogs and puppies are the most susceptible to the disease, according to Scarlett.

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It’s called a “fecal-oral” disease, which is how it’s spread. “Meaning where dogs defecate this virus can live,” said Scarlett.

It’s also an especially hearty virus and can live in the soil for months to years.

The symptoms start off like flu. Scarlett said your dog won’t feel well in general and will then begin “protracted vomiting” and may even experience bloody diarrhea.

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Those symptoms can lead to dehydration and can also be a fatal situation for puppies.

“Prevention is the key here. With puppies, we want to start vaccinating them at six-weeks of age and continue to vaccinate them every few weeks until they’re 16 to 18 weeks of age,” she said.

This leaves the new puppy’s owner with the tough decision of getting the puppy socialized without having them be sick. Talk with your local veterinarian about how to strike that right balance.

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If you have questions about your adult dog’s vaccination status, check with your veterinarian; they should be able to help.