How many animal species have caught COVID? First global tracker has (partial) answers

Mink get it. Hamsters get it. Cats and dogs get it.

They're a few of the many animal species to have contracted COVID-19.

But how many species have been affected? And how many cases have there been in the animal kingdom?

Those are difficult questions to answer – just as it's hard to come up with an accurate total for human cases, since many people don't report a positive test to health authorities. Yet it's an important task, say researchers, because of the possibility that the virus could mutate into a perhaps more transmissible or virulent strain in animals and then pass back to humans.

Now there's a first effort at compiling a global database of animal counts. Amélie Desvars-Larrive, professor at the University of Veterinary Medicine Vienna, and her team of Austrian researchers combed the internet for data from official sources. On July 23, her team in collaboration with the Wildlife Conservation society published the first COVID data tracking dashboard for cases in animals in Scientific Data.

The interactive visualization lets users explore which animals have gotten COVID, how many cases were reported for each species and the source of the data. It also covers what happened to the animals, ranging from mild symptoms like a runny nose to more severe symptoms like myocarditis or even sudden death.

The number of cases reported are undercounts, since there's no systematic gathering of information across countries, among other reasons. But scientists say it is a welcome addition to the body of COVID data.

"[COVID surveillance in animals] has been through either activities at a governmental level or through independent research," says Meghan Davis, professor of environmental health at Johns Hopkins, who was not involved in the study. "What these authors did very well was identifying some of the most likely sources of data and then pulling this information together into a graphical interface.

"This dashboard is incredibly useful at communicating information and bringing together data from multiple sources. People who make public health decisions or are interested in this topic can now interact with the data without needing to go to all of these different sources," says Davis.

"What was new to me was to see [how the number of COVID infections] in the different species compared," says Wim van der Poel, veterinarian and professor of zoonotic viruses at Wageningen University in the Netherlands. Van der Poel was acknowledged in the paper but not involved in the study.

And the limitations of the tracker might help highlight where better reporting or testing initiatives on COVID in animals are needed. "[The dashboard] shows us where we may need to increase our activities," says Davis. "It's really showed me where we have surveillance gaps or lack of reporting."

The study authors acknowledge the gaps.

For example, comparing case counts from country to country isn't useful for understanding which countries have the most cases in animals because "low- and middle-income countries cannot search for COVID in animals as they need to target resources for testing to humans," says Desvars-Larrive.

The statistics about death rates are likely overestimates due to the high number of unreported asymptomatic cases. "The reported cases are only the tip of the iceberg and the symptomatic ones are the tip of the tip of the iceberg," says Desvars-Larrive. "The data don't show the true mortality rate. I think the case fatality rate in animal is low, actually."