COVID-19 Transmission Among Pets

COVID-19 Transmission Among Pets

COVID-19 Transmission Among Pets 1201 1201 Nod
COVID-19 in Pets

On April 22, 2020, the U.S. Centers for Disease Control and Prevention (CDC) and the United States Department of Agriculture’s (USDA) National Veterinary Services Laboratories (NVSL) announced the first confirmed cases of SARS-CoV-2, the virus that causes COVID-19, in two pet cats. These are the first pets in the United States to have tested positive for SARS-CoV-2. The cats, which live in separate areas of New York State, had a mild respiratory illness and are expected to make a full recovery1.  Prior to this, there was a confirmed case of SARS-CoV-2 in one tiger at a zoo in New York State that began to show signs of sickness on March 27th, 2020. Several lions and tigers at the zoo were also tested after showing respiratory symptoms. Public health officials believe these large cats became sick after being exposed to a zoo employee who was actively shedding the virus. All of the cats are expected to recover2.

But can cats transmit SARS-CoV-2 to other cats? One study published in the New England Journal of Medicine (NEJM), inoculated or exposed three domestic cats with the SARS-Cov-2 virus to assess whether transmission could occur via direct contact. This occurred in three pairs between infected cats and cats without any previous infection. On the day after being inoculated, a cat without any previous infection with SARS-CoV-2 was housed with an infected cat. On day 1, the SARS-CoV-2 virus was detectable from two of the inoculated cats. On day 3, the virus was detectable in all three of the inoculated cats with the virus continually being detected until day 5 and in two of the three cats on day 6. The cats with no previous infection of the virus were then cohoused with the inoculated cats on day 1. Two days later, one of the cats with no previous infection had the virus detected in a nasal swab. Five days later, the virus was detected in all three of the cats without any previous infection, which were cohoused with the infected cats.  Interestingly, no virus was detected in any rectal swabs that were tested.  Furthermore, none of the cats in the study showed any symptoms including abnormal body temperature3.

Interestingly, in one study that has not yet undergone peer review or that has been published in a scientific journal, cats and ferrets were found to be the most susceptible to the SARS-CoV-2 virus.  The virus replicated poorly in dogs, pigs, chickens, and ducks4.

There is a public health need to recognize and understand the potential transmission of SARS-CoV-2 especially between members of a household and their pets. However, there is no current evidence that animals play a significant role in spreading the virus or to suggest animals can spread the virus to people. It is recommended though to restrict contact with pets and other animals if an individual is sick with the SARS-CoV-2 virus2. At this time, the CDC recommends against routine testing of animals1.  Of course, this is an evolving situation and more information may be available in the near future.

References:

  1. https://www.cdc.gov/media/releases/2020/s0422-covid-19-cats-NYC.html
  2. https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/animals.html
  3. https://www.nejm.org/doi/full/10.1056/NEJMc2013400?query=featured_coronavirus
  4. https://www.biorxiv.org/content/10.1101/2020.03.30.015347v1