Canine parvovirus (or “parvo”) is a highly contagious virus that attacks a dog’s gastrointestinal tract (stomach and intestines). While it is more common in young puppies (6 to 20 weeks old), older unvaccinated dogs can also get ill.

Parvo is famously tough. It can survive for months in the environment, and it easily resists heat, cold, and humidity. It spreads through:

• Direct contact with an infected dog.
• Contact with infected poop (even trace amounts you can’t see).
• Contaminated objects like food bowls, leashes, crates, and even the hands or clothing of people who have touched a sick dog.

Yes. Constant vomiting and diarrhea can quickly cause severe dehydration. The virus also damages the gut lining and weakens the immune system, which can let harmful bacteria enter the bloodstream and become life-threatening. However, dogs that get immediate veterinary treatment have a 75% to 80% chance of survival.

Because the virus is so hard to kill and resists most household cleaners, prevention is your best defense for protecting your pup’s health and avoiding expensive, intensive treatments.

• Puppies need a series of parvo vaccinations starting at 6–8 weeks old, given every few weeks until they are at least 16 weeks old. They need a booster shot one year later, and adult boosters every one to three years following your veterinarian’s recommendations.
• Do not expose your puppy to other dogs with unknown vaccination histories at public parks, pet stores, or doggie daycares until they have finished all their puppy shots. Visiting a friend’s home with healthy, dog-friendly, fully vaccinated dogs, or attending well-managed puppy classes, is a good alternative for socialization.
• Carry your puppy in public areas; do not let them walk in areas where other dogs have been.
• Keep any dog being treated for or suspected of having parvo completely away from other animals.
• If you handle a dog that might be sick, wash your hands thoroughly and change your clothes before touching any other pets.
• If a dog with parvo has been in your home, all indoor areas, bedding, and bowls must be thoroughly cleaned and then disinfected before bringing another dog inside. Be sure to use products that clearly state on the label that they are effective against parvovirus.