US researchers have detected the Omicron COVID-19 variant in deer on New York's Staten Island, the first time the strain has been found in a wild animal.
They did blood samples and nasal swabs on 131 deer, with 15 per cent of those having virus antibodies.
This not only suggests the deer had previous COVID-19 infections but, according to Pennsylvania State University scientists, it implies they're vulnerable to repeated re-infections with new variants.
There's no evidence, however, to suggest they have been passing the virus to humans.
But the US Department of Agriculture says that, of the coronavirus infections reported in animals, those infections occurred in species that had close contact with a person with COVID-19.
So, what other animals have contracted COVID-19, that we know of?
Dogs
The first report of human-to-animal transmission was, understandably, in man's best friend.
Way back in February 2020, a 17-year-old Pomeranian tested positive for the virus in Hong Kong.
According to the South China Morning Post, the dog had returned a "weak positive" and contracted the virus from its 60-year-old owner, who had tested positive for COVID-19.
The dog spent more than a fortnight in quarantine, eventually testing negative before it was allowed to go home but a report from Live Science said the dog didn't display symptoms of the virus.
It died two days after returning home, but the owner didn't consent to an autopsy so the cause of the 17-year-old dog's death is unclear.
Cats
The first case of a cat being infected with COVID-19 by a human was reported in Belgium in March 2020.
The cat's owner got sick after returning from Italy — which was among the first few countries to experience a major COVID outbreak after China — and about a week later, the cat started displaying COVID-19 symptoms.
Samples of the cat's faeces and vomit were sent to the Faculty of Veterinary Medicine of Liège, with scientist Daniel Desmecht telling Live Science they had high levels of SARS-CoV-2.
Thankfully, the cat recovered after nine days.
Tigers
We first heard about a tiger getting COVID-19 in April 2021.
Nadia, a four-year-old Malayan tiger from the Bronx Zoo in the US, tested positive for the virus alongside three other tigers and three lions.
They had dry coughs and the zoo's chief veterinarian Paul Calle said some of them were wheezing and displayed a loss of appetite.
The zoo later revealed a fifth tiger had also tested positive but never developed a cough.
"Our cats were infected by a staff person who was asymptomatically infected with the virus or before that person developed symptoms," a statement from the zoo said.
All eight of the big cats recovered from the virus.
Mink
Back in November 2020, Denmark had to cull its entire mink population after hundreds of human cases were deemed "related" to mink.
This was one of the earliest known instances of the virus being transmitted from people to animals and then back to people again.
The virus had also been detected in mink in the US, Spain and The Netherlands by this time.
Sanjaya Senanayake, an infectious disease specialist from the Australian National University, said inter-species transmission was possible.
"In the Netherlands, feral cats who were around those mink farms got infected as well," he said.
"So, it might take a feral cat that meets a different type of mustelid — a ferret or some other animal — and then transmits it to that, and then it gets established within those populations.
"It could mutate and then come back to infect humans."
Gorillas
The first known instance of COVID-19 infecting gorillas was reported at the San Diego Zoo Safari Park in the US in January 2021.
Eight gorillas who lived together in a troop tested positive for the virus, with animal handlers sending their faeces to be tested after noticing two of them were coughing.
But the troop didn't have to go into isolation, with handlers deciding to keep them together as separating tight-knit groups can be harmful.
And it was the right call, with all eight gorillas, including a 48-year-old male named Winston who suffered from pneumonia and heart disease, recovering from the virus.
Nine great apes — four orangutans and five bonobos — at the zoo later made history, becoming the first non-humans to be vaccinated against the virus in March 2021.
Hyenas
The Denver Zoo in the US reported the world's first case of COVID-19 in hyenas in November 2021.
The zoo put out a statement saying the hyenas, named Ngozi and Kibo, had very mild symptoms, including "slight lethargy, some nasal discharge and occasional coughs".
The zoo hasn't posted an update on the hyenas' health but given the reports of mild symptoms, it's assumed they've since recovered.
ABC with wires
