CHICOPEE, Mass. (WWLP) – Parvovirus is a growing problem for dogs this spring.

Parvovirus, or parvo, can infect any dog, but it can be especially dangerous for young or unvaccinated dogs. It’s highly contagious and can spread from dog to dog according to the American Veterinary Medical Association.

Once infected, the virus attacks a dog’s gastrointestinal system. Veterinarians say dogs often stop eating when they’re first infected followed by lethargic behavior.

Vaccines are available, and puppies should receive a dose between 14 and 16 weeks old.

Josh Schuner of Holyoke says his dog, Bula, was vaccinated and is due for another vaccination soon, “Not only can your dog get sick but your dog can also make other dogs sick so its not just for just for preventing it on your dog but its more morally ethically responsible especially dog parks because it’s at dog parks here where stuff gets spread around.”

Some signs of parvovirus are loss of appetite, abdominal pain, bloating, fever or low body temperature, vomiting, and severe diarrhea. Constant vomiting and diarrhea can cause dehydration, and damage the dogs intestines and immune system, which can lead to septic shock.