Cobb County’s animal shelter closed Wednesday after at least two dogs died of a highly contagious bacterial infection, authorities said.

Tests on the animals revealed they had streptococcus zooepidemicus, an infection that affects the respiratory system and is often fatal to shelter animals, Cobb spokesman Ross Cavitt said.

The county initially said that two dogs died of the infection, but on Friday, Cavitt said that number may have risen to five. The cause of death in three of the cases has not been determined, but “strep zoo,” as the disease is called, is suspected. Test results will be in next week, Cavitt said.

The shelter will remain closed for at least two weeks, he said. In the meantime, volunteers are asked not to go to the facility and authorities said new animals will be accepted.

Officials believe the infection was brought in by one of the dogs, though they’re not sure which one. Veterinarians are monitoring the remaining roughly 350 animals for signs and symptoms of the infection and giving them antibiotic shots.

“After consulting with our on-site veterinarians, we determined that closing the facility was the only option available,” said Shana Luke, Cobb’s animal services division director. “We will embark on a thorough cleaning process of the entire facility, and put all the animals in the shelter on an antibiotic regimen.”

Luke called the incident unfortunate and said she regrets having to close, but said the health and welfare of the animals is the shelter’s top priority.

Cavitt said the Atlanta Humane Society donated 80 crates to house the animals while the shelter is cleaned at the end of next week.

Animal Services officers are still responding to calls, he said, but aren’t taking in any new pets. Employees are also trying to reach about 80 people who recently adopted animals from the shelter to explain what’s going on. So far, there have been no reports of newly adopted animals getting sick.