two orange tigers sitting beside each other
madeleineshort

If tigers can get it, is there a risk that domestic cats could be involved in spreading it?

Question: This is so bizarre. If tigers can get it, is there a risk that domestic cats could be involved in spreading it? I had thought there was pretty high confidence that non-human animals are not playing a role in the pandemic at this point, but could that be wrong..?

Answer: This upsetting news adds yet another layer to the COVID-19 mystery and our collective anxiety. Plus, as my colleague Jessica points out, people may be extra devastated by the news having watched “Tiger King,” which is still #1 on Netflix. Frivolity aside, I had the same reaction as you, a real — whaaaaaa???!!! So, I turned to science to try to figure it out. And here’s what I’ve learned from my quick research. First off — in response to your question on cat->human transmission, we don’t know. But so far, it seems unlikely and please do NOT do anything rash like banish your cat! Second, we do know a few things, and here’s what I’ve quickly learned:

  1. Cats can contract other types of coronaviruses, like feline infectious peritonitis. (see: Black’s Veterinary Dictionary)
  2. During the SARS epidemic, it was found that domestic cats can contract SARS and can pass it along to other animals housed with them. This was in a laboratory setting, not in “real life” conditions.
  3. More recently, again in a laboratory setting, it’s been shown that domestic cats can become infected with SARS-Cov-2 and can pass it between themselves. This pre-print was just released on the subject last week (it’s not yet peer reviewed and is quite small). The researchers exposed several domestic cats to high levels of the virus and put these cats in cages beside cats who were not exposed. The exposed cats subsequently became infected, as did the unexposed cats. Note: dogs were also included in this study and were found to have low susceptibility to infection.
  4. Now we have this example of Bronx Zoo tigers who all exhibited COVID-19 respiratory symptoms similar to us humans. One of the tigers was tested for COVID-19 and was shown to be infected. The working hypothesis is that a zookeeper, who was asymptomatic at the time of working with the tigers, passed the infection to them. This is the first example of human->cat transmission that we have.
  5. What we do NOT have is any evidence of cats spreading COVID-19 to humans. As folks like to say, an absence of evidence is not evidence of absence. But based on contact tracing done elsewhere, it seems very unlikely that domestic cats are spreading the virus to humans.
  6. Cats can transmit other diseases to humans, but most all of those on the list are parasitic or bacterial. Cornell has a nice breakdown of cat->human transmission. To my knowledge, the only *viral* disease we have evidence of cat-> human transmission is rabies.
  7. CDC has guidance on COVID-19 and pets. This guidance states, “It is still recommended that people sick with COVID-19 limit contact with animals until more information is known about the virus. This can help ensure both you and your animals stay healthy.”
  8. Also, USDA just released a great Q&A on this topic that I recommend you check out.