A recent report in Lancet (Seang et al. 2022) describes a pretty solid case of suspected monkeypox virus (MPXV) transmission from people to a dog. The dog, an otherwise healthy Italian greyhound, had close contact with two people in the household who were infected with MPX, including sleeping in their bed. Twelve days after the signs of MPX started in the owners, the dog developed some mucocutaneous lesions (where skin meets mucous membranes, such as around the lips) as well as some pustules on the abdomen, and an ulcer of the anus. Samples from the skin, mouth and anus were collected and were PCR positive for MPXV. This means genetic material from the virus was present, not necessarily that the dog was infectious to others, though it’s pretty suggestive that the dog could have posed some risk (more on that below). Not surprisingly, gene sequencing of the virus from one of the owners and dog showed they had the same virus strain.
Is this surprising?
Yes and no. We’ve been saying from the start (as with SARS-CoV-2) that we need to assume that a virus can infect a range of speices until we know that it can’t. As I’ve discussed before, we have very little understanding of what species MPXV can infect. As with SARS-CoV-2, some groups have stuck with the line “we have no evidence that dogs can be infected” without acknowledging we have actually have no clear evidence either way. It’s important not to over-react, but it’s also important to be clear, honest and not dismissive of the potential risks.
Does this mean the MPX virus has changed?
Probably not. I haven’t seen any earlier studies that looked at susceptibility of dogs to MPXV, nor any surveillance of dogs in areas where the virus is endemic. It’s possible that some infection of dogs has happened under the radar at a low level in the past.
Does this mean dogs pose a risk for transmission of MPX to people or other animals?
That’s the big question. The dog in this report had PCR-positive samples from its skin lesions, mouth and anus. As we know from SARS-CoV-2, PCR-positivity doesn’t necessarily mean someone is infectious, it just means bits of genetic material from the virus are present. However, I suspect there is some risk here, as PCR-positive skin lesions in particular would seem to me to be a potential source of infectious virus (as they are the primary source of virus in infected people as well).
What do we do now?
Basically the same as we were recommending before, when we were concerned about the potential for infection in dogs and other pets but didn’t yet have the evidence.
If you have monkeypox or have been exposed to monkeypox, limit your contact with other individuals, both human and animal. This includes trying to prevent any direct contact, as well as reducing time spent in close proximity (because of potential aerosol spread) and contact with potentially contaminated items (e.g. sheets, towels, furniture).
Should someone with monkeypox get rid of their pet?
No. Consideration could be given to temporarily re-homing the pet until the person recovers, but that would only be reasonable if the pet hasn’t already been exposed to the person. Otherwise, it creates a potential transmission situation if the pet carries the virus to a new household. As with COVID-19, it’s probably best to keep the pet in the household and let the pet and owner(s) get through the situation together, in isolation.
In this case report, the owners reported being careful to prevent contact between their dog and other animals or people after they themselves developed signs of MPX. That’s good, as it helps prevent spread of the virus outside the household. Given the time frame (the dog’s signs started 12 days after the owners’ signs), the dog was probably infected very early on in the process when we consider the likely incubation period of such a virus in dogs. It’s possible the dog was infected before the owners realized they were infected, or they didn’t (or couldn’t) isolate the dog sufficiently from themselves to prevent exposure.
Should someone be worried about getting monkeypox from their pet?
No. This is pretty much the same discussion as we had with SARS-CoV-2. Most of the risk is to, rather than from, the pet. If a pet has MPX, it likely got it from its owner. So, pets are unlikely to be the primary source of MPX in a household. The transmission risks are probably greatest if the pet is infected and then encounters people outside the household while it has skin lesions. That’s hopefully going to be rare, but probably of greatest concern for veterinarians.
Should I stay away from dog parks? I don’t know who’s going to be there.
That’s overkill. No, we can never guarantee any random dog doesn’t have MPX. But really we can never guarantee much in life, and the risk posed by random, short term, outdoor contacts at a dog park are presumably exceptionally low (although contact with random dogs at dog parks does carry other infectious disease risks of course…).
What if an animal exposed to MPX needs veterinary care?
Stay tuned. We’ll have more details about recommendations for that ASAP. The US CDC has posted some of their recommendations for veterinarians and animal health officials (but this is not necessarily the same process that will be used in other jurisdictions).
Finding MPX in a dog in a household with close contact with two owners who have MPX isn’t overly surprising. It’s a bit concerning and something we definitely need to investigate more, but nothing that should cause panic.