There seems to be lots of news on Covid in animals this week – and most of it looks on the surface to be really bad news. So, as the UK opens up again and the Delta variant spreads through populations – is your pet likely to be carrying the virus? Are they a risk to you? Or are you a risk to them?
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What’s the big worry?
Well, it was already established that the virus behind Covid, SARS-CoV2, can spread from humans to other animals. We saw in the Netherlands, amongst other countries, that it can cause significant disease in some species, such as mink; and there were significant concerns about the spread from mink back to humans. In fact, this might be a concern if you have pet ferrets. However, there is a new study, published this week, that has really worried a lot of people.
Study finds that “Covid is common in pet cats and dogs”
Researchers from Utrecht University in the Netherlands have reported this week that, in households where a human was infected with Covid, their dogs and cats were also likely to have or have had the virus.
The researchers were reportedly worried that “pets could act as a reservoir of the virus and reintroduce it into the human population”.
So how common is human to animal transmission?
It was relatively common, but it’s worth bearing in mind the numbers. From 196 households with a known human infection, 310 dogs and cats were tested. 6 cats and 7 dogs showed signs of an active infection (just over 4%). That doesn’t, however, mean that these animals were infectious: the PCR test used is a very good, very sensitive test, but it doesn’t tell us the degree of viral shedding going on. It also doesn’t tell us whether these dogs and cats were infected, or just carrying the virus.
More interesting was the number of pets with antibodies showing previous infection. This was much higher – as you’d expect – at over 17%. And this is solid evidence that these pets had indeed been infected, not just transported viral particles around.
A similar study in Canada found rather higher numbers had antibodies (67% of pet cats and 43% of pet cats) – including, interestingly, that 3% of stray cats tested positive. But their headline conclusion was that the closer contact, the higher the risk – and cats sleeping on people’s beds were at the biggest risk! Given what we know about the virus, that makes sense.
But are these pets in danger?
In most cases no – 75% of cases were asymptomatic, and of the remainder, symptoms were mild and self limiting. Essentially, cats and even more so dogs are not a great host for the virus: it doesn’t replicate well in them. That said, 3 patients in the Canadian study were reported to have had severe disease, and the authors point out that cats are more susceptible than dogs.
So the risk to cats isn’t quite zero – but it is very, very low.
What about humans? How many humans have been infected by their pets?
Well, the simple answer is that no-one knows for sure. However, the only people proven to have been infected by a cat were some zookeepers who seem to have contracted Covid from the tigers they were caring for. And as a colleague of mine once put it “if you’re close enough to a tiger to catch Covid, you have bigger problems to worry about.”
The bottom line is that, as BVA Vice President Daniella dos Santos said, “There is no evidence that pets are passing COVID-19 to their owners”.
Can pets be vaccinated?
There’s no licensed vaccine yet – but interestingly, the animal drug company Zoetis (a spin off from Pfizer) has started trialling a vaccine. In fact, they have been supplying it to some zoos to protect the endangered animals there.
However, pets don’t seem to have any significant role in spreading the virus to people; and almost never get ill themselves. So it’s difficult to imagine that routine vaccinations for dogs and cats will ever include a Covid component.
So what should we do?
Well, if your cat sleeps on your bed and you feel unwell, it might be best if they slept elsewhere until you’re better. And it’s probably wise to use good hand hygiene after fussing dogs or cats that you don’t own. If you (or for that matter your pet) is in a clinically vulnerable group it’s probably worth being doubly careful, even if you are vaccinated. For cats, that seems to mean significant or chronic lung disease.
But overall – the risk is much lower than catching Covid from your human family and friends! So on this count – the pets aren’t a problem.