Until now, the transmission of monkeypox from humans to animals was only a theoretical possibility. But in France, this case can now be proven in two men and their dog. The US epidemic authority is responding with updated recommendations.

There has apparently been a case in France of humans passing the monkeypox virus to a dog. It was the first known case of human-to-animal transmission, confirmed Rosamund Lewis, who is responsible for fighting the disease at the WHO, the Washington Post. Lewis is not surprised by the development, which had been expected by experts.

The corresponding case was described in the journal “The Lancet” by a research team for infectious diseases at the Sorbonne in Paris. It affects two men who were diagnosed and treated at the Pitié-Salpêtrière hospital in Paris in early June. They live together in a household but not in an exclusive relationship with each other. Both had developed symptoms of monkeypox, including skin rashes, fatigue, headaches and fever, about six days after having sex with other people.

Twelve days after the onset of these symptoms, her four-year-old Italian greyhound also showed signs of illness. He had multiple lesions on his skin and mucous membranes, including large pus-filled pimples on his abdomen and an ulcer on his anus. The dog then tested positive for the same type of monkeypox as one of the owners.

The men said they let the dog sleep in their bed with them, but from the onset of their own symptoms they made sure to keep the animal away from other animals or people. The dog’s symptoms developed about 13 days after the men’s symptoms.

“To the best of our knowledge, the kinetics of onset of symptoms in both patients and subsequently in their dog suggest human-to-canine transmission of monkeypox virus,” the report’s authors wrote. “Based on the dog’s skin and mucosal lesions, as well as positive monkeypox virus PCR results from anal and oral swabs, we suspect a genuine canine disease, not simple transmission of the virus through close human contact or airborne transmission (or both).”

The authors suggested that the study should start a discussion about whether pets need to be isolated from their owners when they have monkeypox. On August 12, the US Centers for Disease Control and Prevention updated its website to advise that dogs can be infected with monkeypox. The same pages list several other animals known to be potentially susceptible to monkeypox, including prairie dogs, squirrels, marmots, chinchillas, opossums, hedgehogs, shrews, monkeys, and great apes.

It’s also possible for certain mice and pet rabbits to get the virus, but it’s not known if cats can contract monkeypox, the CDC notes. “People with monkeypox should avoid contact with animals, including domestic and wild animals, to prevent the spread of the virus,” advises the CDC.

Since the beginning of the monkeypox outbreak, cases of infection have been heavily concentrated in men who have sex with men. However, the relevant experts repeatedly point out that anyone, regardless of their sexual orientation or behavior, can become infected with the virus and spread it.

Most commonly, monkeypox spreads from person to person through direct contact with an infected person’s rashes, scabs, or bodily fluids, including pus, mucus, and saliva. This contact can occur during sex, but also during non-sexual close contact. Transmission through materials contaminated with bodily fluids, such as clothing or bedding, is also possible.

The virus can also be spread through respiratory droplets – small droplets of saliva and mucus – that are expelled from the mouth. This transmission path is more likely with “longer” personal contact or intimate physical contact, such as kissing.

(This article was first published on Wednesday, August 17, 2022.)