The first case of human-to-dog transmission of the monkeypox virus was verified in a report published by The Lancet medical journal this week.
A four-year-old Italian greyhound, who slept in the same bed as two infected males in an open sexual relationship, developed symptoms 12 days after the men tested positive in Paris last June. Along with general malaise, fever and loss of appetite, the dog developed skin lesions similar to his humans.
“Given the dog's skin and mucosal lesions as well as the positive monkeypox virus PCR results from anal and oral swabs, we hypothesize a real canine disease, not a simple carriage of the virus by close contact with humans or airborne transmission (or both),” the study authors (Seang, et al) found. The authors also called for further research and discussion about infected pet parents isolating from their pets.
The men reported keeping their dog away from other humans and animals once their own symptoms appeared. It’s unclear whether the infected dog will be able to transmit the virus back to humans.
Prior to this event, only animal-to-human transmissions had been reported. A landmark 2003 outbreak among humans in six U.S. states was traced to rodents imported from Ghana. The rodents transmitted the virus to prairie dogs with whom they’d been temporarily housed. The prairie dogs were sold as pets before their symptoms developed.
Dr. Rosamund Lewis, technical lead on the monkeypox response for the World Health Organization (WHO), said that this week’s breakthrough case grounded possibility into reality: “On a number of levels, this is new information," Lewis said during a Washington Post Live event last Monday “It's not surprising information, and it's something that we've been on the watch out for.”
The leaping of viruses across species often stokes concerns about mutation. “As soon as the virus moves into a different setting in a different population, there is obviously a possibility that it will develop differently and mutate differently,” Lewis said.
Lewis noted that WHO is partnering with World Organization of Animal Health and the Food and Agriculture Organization to address concerns about human-to-animal monkeypox transmission. She is a proponent of separating pets from infected family members, noting “most pets will not be at risk, it may only be those who are actually in the household of someone who's infected,” she said.
On Wednesday, The U.S. Centers for Disease Control and Prevention (CDC) updated their monkeypox page to indicate that dogs can be infected by the virus. To date, it is unknown whether cats can be infected by humans or other animals.
Other close contact by which humans can infect their pets include cuddling, hugging, kissing, licking and sharing food. The CDC advises infected persons to avoid close contact with people and any animals aside from their pets.
Pets who had close contact with someone with monkeypox symptoms should be kept at home and away from other animals and people for 21 days after the most recent contact, the CDC said. Infected people shouldn't get close to their exposed pet(s); they should ask someone else within the home to look after them if possible.
If the infected person and the pet did not have close contact after symptoms started, the CDC recommends asking someone who lives elsewhere to look after the animal until the human is fully recovered from the virus.