Lawrence Humane Society has had an outbreak of parvovirus in two puppies this week.

Parvovirus, which is rare in the winter, is very contagious and can be fatal. It can cause vomiting followed by lethargy, weakness and diarrhea.

One of the infected dogs had to be euthanized; the other is at a local veterinarian’s office.

Midge Grinstead, executive director of the society, said the dog portion of the shelter is under quarantine and staff members are taking extra precautions to prevent a spread of the virus. No dogs are being taken out, and a moratorium has been placed on adoptions of puppies younger than 6 months. Adoptions of puppies older than 6 months must first be cleared by a veterinarian.

“In this case, these puppies were all vaccinated with two vaccines,” Grinstead said. “It’s frustrating because you think you’re doing everything perfect and things still happen.”

Grinstead said that the situation is under control, but if the virus were to spread, they would consider shutting down the shelter.