Is COVID-19 transmittable between humans and animals? Are masks necessary? We explore precautions  your clinic should be taking

We’ve heard multiple reports that companion animals cannot carry or transmit the novel coronavirus COVID-19. This has now been refuted with domestic cats, dogs, and big cats having contracted COVID-19.

A 17-year old Pomeranian belonging to a coronavirus patient in Hong Kong tested “weak positive” for COVID-19, and veterinarians assumed that the dog had picked up the virus from its caretaker.

The recent case of a tiger at the Bronx Zoo testing positive for COVID-19 leads to even more questions about whether previous assumptions about whether pets can carry and transmit this virus are true. Even before two dogs in Hong Kong tested positive for COVID-19, some pet parents were already opting to err on the side of caution, having their dogs wear masks during walks through heavily populated city centers.

CDC and AVMA representatives weigh in

After news of the first COVID-19 positive tiger broke, we learned that three lions and three more tigers at the Bronx Zoo tested positive after developing symptoms. The big cats were under the care of an asymptomatic keeper, again suggesting that humans may transmit the disease to animals even without showing any signs of COVID-19.

MarketWatch asked American Veterinary Medical Association President Dr. John Howe whether it’s possible for humans to get COVID-19 from pets. Howe replied that “the answer at this point is no. At this time, there is no evidence that companion animals, including pets, can spread COVID-19 to people or that they might be a source of infection in the United States.” But not having diagnosed a case yet doesn’t mean that animals can’t spread COVID-19 to humans. In the future there may be cases of this occurring.

The reason for this is COVID-19 requires special ‘cell surface proteins’ which act like doors to enter a body and cause infection. Without these ‘doors’, viruses can’t attach to human or animal cells and this explains why some species catch certain viruses but can’t spread it to other species. ‘ACE2’ is the ‘door’ COVID-19 uses to infect humans. The concerning part is that this specific cell surface protein called ‘ACE-2’ is present in both humans and our canine friends, making COVID-19 theoretically possible to be passed from humans to dogs and potentially vice-versa.

On its Coronavirus and Animals page, The CDC repeats Dr. Howe’s statement and maintains that “CDC has not received any reports of pets becoming sick with COVID-19 in the United States. Furthermore, they recommend that people who have COVID-19 should restrict contact with pets and other animals, at least until more information is known.

Neither CDC nor AVMA recommend masks for pets. Instead, they recommend that those who are sick with COVID-19, or who suspect that they may have the virus but haven’t tested positive should:

• Limit contact with their pets and other animals
• Have another member of the household care for pets
• Avoid contact such as petting, snuggling, being kissed or licked
• Avoid sharing food or bedding with their pets. If you have a young pet who usually sleeps in your bed or likes to wander, consider a spacious puppy pen

In the event that someone who has or suspects they have COVID-19 must take care of their own pet, CDC recommends handwashing before and after contact with pets. Furthermore, they recommend that the patient wear a cloth face covering.

Given that there is evidence that all the animals who have caught COVID-19 did so from the virus crossing from human to animal, it is very reasonable to suggest that all caregivers and those who interact with animals wear masks to prevent droplet transmission. The troubling part is that pet parents and animal care workers can transmit the virus to the animals they are in close contact with, without even knowing they are infected with the viruses themselves.

What about cats? 

There have been cases of cats getting COVID-19 in Hong Kong and Belgium to name a few countries. So the question must be asked: if a cat is in contact with a COVID-19 positive human, what steps should caregivers take?

• Triage the case – if the case is not critical or an emergency, please reschedule until after the caretaker has cleared quarantine
• Wear PPE when examining the cat – a mask, eye protection, gloves and a disposable or washable gown
• Minimal handling of the cat
• Practice good hand and environmental hygiene
• If you need to hospitalise a cat who has had exposure to a COVID-19 positive human patient, it should be isolated from other animals and staff should wear PPE when cleaning cages or handling the cat
• Only perform essential procedures to any cat in contact with a COVID-19 positive human. A P2 mask is required for all in-contact staff if doing a procedure where aerosol may be generated. This includes intubation. Ensure you do a fit check on your mask

Protect your practice 

Even though animal patients don’t need to wear masks, there are ways that you can protect your practice during the COVID-19 pandemic. Consider:

• Implementing telemedicine
• Transferring patients to your clinic in the parking lot
• Postponing elective procedures
• Wearing a mask and practicing safe social distancing when meeting with pet parents
• Accepting online payments when possible
• When clients enter the office, ask them to wear a cloth mask, practice social distancing, and sanitize common areas afterward. Also make it mandatory that they hand sanitize before entering the premises
• Temperature test your staff twice a day (at shift sign-on and around 2pm). Any staff with temperatures 99.5F or above should be sent home.

There are many unknowns and the situation continues to evolve. For in-depth information, read AVMA’s COVID-19 FAQs for Veterinarians.