A groundbreaking study from the American Society for Microbiology reveals that domestic cats can play an instrumental role in the transmission of SARS-CoV-2, the virus responsible for COVID-19. In fact, our feline companions can not only contract the virus but also spread it to other cats and even contaminate their environment.
This study, published in the journal Microbiology Spectrum, offers vital insights into the potential risks associated with cats infected with the virus.
“In practice, after introduction of SARS-CoV-2 in our household, we should see our cat as part of the family regarding virus transmission,” said study co-author Professor Wim van der Poel.
To understand the risks related to COVID-19 infection from cats, Professor Van der Poel and his team conducted an extensive study. They tested 16 cats, which were exposed to the virus in several ways.
Some cats were directly exposed to the SARS-CoV-2 virus obtained from a human patient naturally infected with COVID-19. Other cats were exposed indirectly, either through contact with a directly exposed cat or through exposure in a pen where an infected cat was housed.
Throughout the study, the researchers closely monitored the cats and carried out regular testing. They collected nasal and oropharyngeal samples, along with blood samples.
The team also gathered environmental samples from the pens. All samples were subsequently tested for SARS-CoV-2. Additionally, the blood samples were scrutinized for SARS-CoV-2 antibody development.
The sampling process was meticulous and spanned three weeks, starting from the day the cats were directly exposed to the virus. The team took nasal and oropharyngeal samples three times during this period.
Similarly, they collected oral and rectal samples 15 times. The goal was to evaluate both direct and indirect transmissions of SARS-CoV-2 between the cats.
The team found that cats are indeed susceptible to SARS-CoV-2. Furthermore, infected cats can efficiently transmit the virus to their peers and contaminate their environment. While the environment can potentially be infectious, this infectiousness rapidly decays over time.
“SARS-CoV-2 transmission between cats is efficient and can be sustained,” said Professor Van der Poel. “Infections of cats via exposure to a SARS-CoV-2-contaminated environment cannot be discounted if cats are exposed shortly after contamination.”
The team discovered that the average duration of infectiousness was slightly more than one-third of a day. This duration was estimated based on the periods when the virus was detected in the cats’ excreta, including oral/nasal fluid or feces.
To ensure the safety of all involved, Van der Poel noted that the team did not expose humans to the infectious cats. “Our animal handlers were always fully protected.”
Yet, he cautioned that we should consider the risk of transmission from our pets: “We must assume that cat owners can be infected by SARS-CoV-2 infected cats since these cats excrete infectious virus.”
Moving forward, the research team plans to further investigate SARS-CoV-2 susceptibility in different animal species and delve deeper into the risks associated with virus transmission.
Research has shown that SARS-CoV-2, the virus responsible for COVID-19, has the ability to infect various animal species, not just humans.
Many of the earliest reported cases of COVID-19 were linked to a seafood market in Wuhan, China, which also sold live wild animals, suggesting a possible zoonotic origin. In fact, SARS-CoV-2 is part of a larger family of coronaviruses known to cause diseases in a range of mammals and birds.
The exact pathway of transmission to humans remains under investigation, but the virus is believed to have originated in bats and may have passed to humans through another species.
Several animals, including household pets such as cats and dogs, have been reported to be infected with SARS-CoV-2, mostly after close contact with people with COVID-19.
In addition to domestic animals, the virus has also been found in farmed mink, and these animals appear to be particularly susceptible to the virus. There have been instances of mink transmitting the virus back to humans, highlighting the potential for a feedback loop of transmission between humans and animals.
Experiments have shown that a variety of animals can be infected with the virus in a laboratory setting, including ferrets, hamsters, and monkeys. This research has helped scientists understand how the virus spreads and impacts different species, aiding in the development of vaccines and treatments.
Zoos have also reported infections in animals. For example, lions and tigers at the Bronx Zoo in New York were confirmed to have COVID-19 in April 2020, likely infected by a caretaker. And gorillas at the San Diego Zoo tested positive for the virus in January 2021.
The Centers for Disease Control and Prevention (CDC) maintains that the risk of animals spreading SARS-CoV-2 to people is considered to be low, and the primary mode of transmission is human-to-human through respiratory droplets. However, it is recommended that people with COVID-19 limit contact with pets and other animals until more is known about the virus.
On the other side of the equation, there is concern about humans transmitting the virus to wildlife, particularly to species that are already endangered. This could introduce a new disease threat and potentially decimate populations that are already vulnerable.
For example, great apes share 98 percent of their DNA with humans and are known to be susceptible to human respiratory illnesses, hence there’s concern about the potential impact of COVID-19 on these species.
Research into how SARS-CoV-2 affects animals and the potential for transmission between humans and animals is ongoing. It’s a critical part of the puzzle in understanding this virus and managing the pandemic.