By Haley Ott

The U.S. Centers for Disease Control and Prevention has updated its monkeypox guidance to include dogs as animals that can catch the virus. The CDC tweaked its guidance after the first case of a pet dog suspected of contracting the virus from its owners was documented in France.

Scientists said in a paper published last week that they'd found evidence of human-to-dog transmission of monkeypox. Before that, it was not clear whether the virus could be spread to dogs.

Monkeypox was declared a Public Health Emergency of International Concern by the World Health Organization on June 23. It is transmitted between humans through close contact with lesions or bodily fluids, and it's spreading in the United States and Europe among people who have not traveled to areas where it is known to be endemic.

The case in France involves two male partners who live together and were not sexually exclusive. The men started showing symptoms of monkeypox a few days after sleeping with other partners.

Twelve days after they first showed symptoms, their pet dog — a four-year-old Italian greyhound — also developed lesions and then tested positive for the monkeypox virus.

The men reported having slept alongside their dog, though they said they had been careful to prevent him from coming into contact with any other people or pets from when their own monkeypox symptoms began.

In countries where monkeypox is endemic, wild animals, including rodents and primates, can carry the virus. Captive primates in Europe have also contracted monkeypox from coming into contact with imported animals that were sick, but infection in domestic pets like dogs and cats had not previously been reported.

"To the best of our knowledge, the kinetics of symptom onset in both patients and, subsequently, in their dog suggest human-to-dog transmission of monkeypox virus," the researchers said in the study published in The Lancet.

The researchers called for further investigation into secondary monkeypox transmission via pets.

"Our findings should prompt debate on the need to isolate pets from monkeypox virus-positive individuals," they wrote.

The CDC recommends that people with monkeypox avoid close contact with animals, and that pets that have not been exposed to the virus be cared for by friends or family in another home until the owner or owners fully recover.