A report from the U.S. Centers for Disease Control and Prevention confirms the pit bull became sick last summer. After a fever and frozen jaw grew worse, the animal was put down.
Four days later, the dog’s owner developed a fever and began coughing blood. The CDC reports when the man became sicker, a test found he was infected with pnumonic plague. Also infected were two veterinary workers who had contact with the animal and a friend of the owner.
The CDC says the dog’s remains were then tested, and came back positive.
The man was in the hospital for three weeks before recovering. The other three people were also treated successfully.
"Pneumonic plague is the worst form," said John Douglas, of Tri-County Health Department in Colorado.
"It's the one that you least want to get," he told ABC. "You get sick fast and the chances of getting a rocky or even fatal course are increased."
Records indicate this is the first time in US history a human has been infected with the disease by a dog.