Now that human-dog transmission of monkeypox has been identified, there’s a lot more interest in what to do about animals that have been exposed to infected people. As more people get monkeypox, more animals will be exposed. We want to reduce the risk of animals getting infected (and possibly then infecting more people), while at the same time not causing undue stress on the animals or their owners.

This is a big déjà vu moment, as this is pretty much the exact same topic I had to write about for SARS-CoV-2-exposed animals at the start of the pandemic.  Similarly, specific guidance in this situation is tough to develop because of knowledge gaps, emerging new information, and differences between households, lifestyles, risk tolerance and other factors. Nonetheless, we can break down some general guidance into three main approaches:

1) Remove the pet from the infected household ASAP

  • This one gets mentioned as an ideal option, but I think it’s actually probably the worst one unless it’s certain that the animal has not yet been exposed to the infected person, or anything potentially contaminated by the virus.
  • Prompt removal of the pet would reduce the risk of a pet getting infected, but it also increases the risk of a pet spreading monkeypox. If the animal was already exposed to the infected person, it could already be infected and incubating the virus. Moving the animal therefore creates a risk of moving monkeypox to another household or facility and exposing others.  (The animal could also potentially have virus on its fur that it picked up from the contaminated home environment, even if it’s not infected.)
  • Considering how little we know about the risks, I’m more concerned about the implications of an animal spreading monkeypox outside the household than I am about the pet getting monkeypox in a household where the virus is already present but being contained, and where the animal has probably already had a lot of exposure.

2) Keep the pet in the house and use isolation measures to prevent transmission to (or from) the animal

  • This is the ideal response, in my mind. It’s not easy, though, in part because we don’t really understand the likelihood of human-to-dog or dog-to-human transmission risks in households.
  • Pet contact with skin lesions of infected people probably poses the biggest risk of transmission to the pet, but other types of contact also have to be considered. The degree of risk from aerosol transmission is still controversial.

Here are some basic isolation precautions that would help prevent transmission to pets (and they also help prevent transmission between people):

  • If there are uninfected (or not known to be infected) people in the household, they should be the animal’s primary caregiver(s).
  • Keep the pet away from monkeypox skin lesions.
  • Keep monkeypox skin lesions covered, whenever possible.
  • Limit contact between people and the pet as much as possible.
  • Keep the pet in a separate room or area of the house as much as possible (being practical and considering the pet’s welfare).
  • Keep the pet away from bandages, clothing or other materials that have come into contact with the infected person’s skin, especially skin lesions.
  • Keep the pet off furniture used by people (e.g. couch, bed).
  • Limit the amount of time the pet is in the same airspace (especially small, enclosed areas).
  • Don’t let the pet sleep in the same bedroom as people.
  • Pay close attention to hand hygiene, especially before any direct contact with the animal, or with things like food and water bowls.
  • Maximize ventilation in the house.  If possible, have a HEPA filter running in areas where the infected person tends to spend time (especially if the pet is in the same area).

To mask or not to mask?  That is the question.

  • Mask use will reduce the risk of aerosol transmission. It would make sense for an infected person to wear an N95/KN95 respirator or equivalent when in close proximity to the pet. That’s tough to maintain over time, but at least doing it when close contact is required can be practical.

3) Keep the pet in the house and carry on

  • This approach is based on an assumption that the pet is already exposed and/or that isolation measures will not be able to be done effectively. I understand those points and there’s some validity to them. However, it’s hard to support a “do nothing” approach. I’d rather see “do as much as you can from the list above” versus simply surrendering and saying “what happens, happens.”

In my (limited) experience to date, a combination of approach #2 and #3 has been most common. By the time people are diagnosed and think about potential risks to pets, there’s already been lots of exposure of the pet. They then try to take some precautions like limiting contact, keeping the pet away from their skin lesions and keeping the pet out of the bedroom. It’s hard to strictly isolate in the household when you have to care for the animal, and motivation decreases over time (especially when people think that they’re not able to strictly isolate from their pet anyway). So, in the end, measures taken tend to be limited. That’s not a criticism, it’s a reality. Pets can be peoples’ support systems when they are going through a tough time. All things considered, while owners don’t want to infect their pet, they often drift from “strict isolation” to “let’s do what we can do.” That’s still useful, though.

What if the owner cannot care for the animal and/or the animal has to be moved?

In some situations, the pet might have to be temporarily removed from the household.  These situations could include if the infected person cannot care for the pet, if the pet can’t be safely managed by the person (e.g. they have to go in an elevator and through busy common areas to go outside multiple times a day), or if the owner ends up hospitalized and no one else is present in the household. There are a few possible approaches for handling this:

  • If the owner cannot care for the pet but the pet can stay in the home, someone else can come and care for the pet a couple of times a day (this is easier with cats and caged pets). This avoids having to move the pet to another household or facility, and makes it easier to minimize exposure to the pet and to facilitate use of personal protective equipment, as needed.
  • If the pet has to be moved, it should be moved to a household or facility where it can be easily contained and managed, with as few people as possible, no high-risk individuals including kids or immunocompromised persons, and no other animals. The pet’s caretaker would have to understand and accept the unknown degree of risk of transmission of mokeypox from the pet (as it’s pretty much completely unknown).

These approaches are far from impossible, but require some work and still come with a good degree of uncertainty.

Regardless of the option chosen, there needs to be an effort to reduce exposure of the animal to other animals and people:

  • Veterinary care: Only if essential and it can’t be postponed for a few weeks.
  • Grooming: Big no.
  • Time in the yard: Short, supervised periods are okay. We want to prevent exposure of wildlife or through-the-fence transmission to neighbouring people or animals. (I’ve seen fence line transmission of both canine flu and canine parainfluenza; different bugs, but it shows there’s some degree of viral transmission risk with this kind of contact.)
  • Walking: This comes down to context and need. If the animal can be walked but still kept away from others, the risk is negligible. That might be very easy or next-to-impossible depending on the situation, so it would need to be assessed on a case-by-case basis, and the dog walker needs to be diligent about avoiding close contact between the dog and others.

How long do these measures need to be kept in place?

That’s a tough question too. Measures to reduce the risk of transmission from the owner should be maintained until the owner has been told they are no longer infections. Often, that’s considered to be 21 days after onset of infection.

But (there’s always a but)…

We have to think about the other part of our pet concerns: whether an exposed pet could infect someone else. If we say the person was infectious until day 21, then the pet could have been exposed up until day 21. So, if we use a similar 21 day isolation period for exposed animals (which is a huge assumption in itself), that would start at the end of the owner’s isolation period. That’s hard to enforce since it’s not what’s done for human contacts, but since we know nothing about whether dogs, cats and other species can be subclinically infected (i.e. infected without obvious signs of illness) and the risk of transmission from animals if the are infected, some degree of prudence is warranted. At a minimum, I’d want to keep an exposed dog from situations like groomers, kennels and off-leash dog parks for a while after the owner is considered no longer infectious themselves.

As always, these are initial thoughts and subject to change as we learn more. But infection control isn’t rocket science. It’s a lot of basic measures that apply to a wide range of situations, so I think the approaches outlined above are a good starting point.