Six weeks ago, in APHIS: Confirmation of COVID-19 in Two Pet Cats in New York, we looked at the first report of the SARS-CoV-2 virus in companion animals in the United States. While only rarely reported, we'd seen similar reports from Hong Kong (see Dog Tested `Weakly Positive' For COVID-19 and Pet cat tested positive for COVID-19 virus).
Three weeks earlier,in Susceptibility of Ferrets, Cats, Dogs & Other Domestic Animals to SARS-CoV-2, we looked at preprint study by Dr. Hualan Chen et al. which looked at the susceptibility of a variety of domestic animals to the SARS-CoV-2, the virus that causes COVID-19 in humans.
We found that SARS-CoV-2 replicates poorly in dogs, pigs, chickens, and ducks, but efficiently in ferrets and cats. We found that the virus transmits in cats via respiratory droplets. Our study provides important insights into the animal reservoirs of SARS-CoV-2 and animal management for COVID-19 control.And since then we've seen additional companion animals (along with captive lions and tigers, and farmed mink) test positive for the virus. The AVMA (American Veterinary Medical Association) maintains a list of SARS-CoV-2 infections in domestic, farmed, or captive wildlife (e.g.. dogs, cats, tigers, lions & mink). Follow the link for more than a dozen detailed reports.
In-depth summary of reports of naturally acquired SARS-CoV-2 infections in domestic animals and farmed or captive wildlifeThe AVMA also has a detailed web page dedicated to SARS-CoV-2 infection in animals, including dogs and cats.
Yesterday the CDC's MMWR published an early release report on the two cats in New York that I mentioned at the top of this blog. I've excerpted the summary, and the discussion portion of the report.
Follow the link below to read it in its entirety.
Early Release / June 8, 2020 / 69
Alexandra Newman, DVM1; David Smith, DVM2; Ria R. Ghai, PhD3,4; Ryan M. Wallace, DVM3,4; Mia Kim Torchetti, DVM, PhD5; Christina Loiacono, DVM, PhD5; Laura S. Murrell, MA3,4; Ann Carpenter, DVM3,4; Scott Moroff, VMD6; Jane A. Rooney, DVM7; Casey Barton Behravesh, DVM, DrPH3,4 (View author affiliations)View suggested citation
What is already known about this topic?
A small number of companion animals worldwide have been naturally infected with SARS-CoV-2, the virus that causes COVID-19.
What is added by this report?
Two domestic cats with respiratory illnesses lasting 8 and 10 days are the first reported companion animals with SARS-CoV-2 infection in the United States. Both cats were owned by persons with suspected or confirmed COVID-19, and both cats fully recovered.
What are the implications for public health practice?
Human-to-animal transmission of SARS-CoV-2 can occasionally occur. Animals are not known to play a substantial role in spreading COVID-19, but persons with COVID-19 should avoid contact with animals. Companion animals that test positive for SARS-CoV-2 should be monitored and separated from persons and other animals until they recover.
An estimated 76 million pet cats live in the United States, and approximately 70% of U.S. households own at least one pet (9). Close interactions between humans and pets create opportunities for zoonotic disease transmission. In both cases presented in this report, the cats with positive test results for SARS-CoV-2 had close epidemiologic links to owners with suspected or confirmed COVID-19.
In addition, human symptom onset preceded that in cat A by 9 days and in cat B by 8 days. No identified onward human or animal infections were attributed to these animals. This evidence supports findings to date that animals do not play a substantial role in spreading SARS-CoV-2, although human-to-animal transmission can occur in some situations. Companion animals that test positive for SARS-CoV-2 should be monitored and separated from persons and other animals until they recover.
Both animals in this report were initially tested by laboratory A as part of a passive COVID-19 pet surveillance program that operated independently from state and federal health agencies. This method of surveillance was unable to routinely obtain epidemiologic information regarding SARS-CoV-2 exposures before testing. CDC and USDA have identified four situational testing categories§ (10); one of the four categories recommends testing symptomatic animals with close contact to a person with suspected or confirmed COVID-19. Epidemiologic investigation conducted after positive SARS-CoV-2 test results were reported found that both cat A and cat B fit this situational category.
Currently, CDC and USDA recommend that epidemiologic information be collected before companion animal SARS-CoV-2 testing, and that the decision to test animals be coordinated with state public health veterinarians and state animal health officials using a One Health approach, to ensure that animal and public health responses occur in a timely and effective manner. Laboratory A’s passive surveillance program operated for a limited period to better understand the impact of SARS-CoV-2 on animals at risk for infection and did not divert resources necessary to conduct human SARS-CoV-2 testing, consistent with CDC and USDA guidance.
Establishment of the U.S. One Health Federal Interagency COVID-19 Coordination Group (OHFICCG) in February 2020, and routine communication between state and federal One Health partners have been instrumental in ensuring a coordinated government response to the One Health aspects of COVID-19. This One Health coordination platform allows for collaboration and rapid information-sharing across sectors while also facilitating alignment of research, priorities, and messaging regarding the human, animal, and environmental aspects of COVID-19. Laboratory A, state partners, and members of OHFICCG coordinated information sharing during this investigation. Information from this investigation informed OHFICCG guidance development for managing SARS-CoV-2–infected animals, including guidance for when animals with positive test results should resume normal activities. This investigation provides further support for the utility of a One Health approach to addressing zoonotic diseases such as COVID-19 to safeguard the health, welfare, and safety of humans, animals, and their shared environment.
Members of cat A and cat B households; veterinary clinics in New York state and Connecticut; laboratory A; officials from the New York State Department of Health, New York State Department of Agriculture and Markets, and Connecticut Department of Agriculture; U.S. Department of Agriculture One Health Coordination and National Veterinary Services Laboratories staff members; staff members from CDC’s COVID-19 One Health Working Group.