Minnesota zoo animals are getting their COVID shots, too

Matilda the moose became one of the millions of Minnesotans to get vaccinated against COVID-19 after a quick poke from Anne Rivas, director of animal health at the Minnesota Zoo.

Then because a moose has no interest in a $200 Visa gift card or a college scholarship, Matilda got her promised incentives — sweet potatoes, apples and biscuits.

Matilda is among the dozens of Minnesotan zoo animals that will receive a shot over the next month, thanks to a donation from New Jersey-based Zoetis. The animal health company started working to develop the vaccine after a dog in Hong Kong tested positive for the virus early in the pandemic.

Zoetis received approval for experimental use of the vaccine and began distributing doses to zoos across the country in 2021. Rivas said the Minnesota Zoo plans to vaccinate about 100 animals known to be at risk of COVID-19 — a roster that includes cats, primates and deer-related animals, known as cervids.

The river otters and ferret at the zoo in Apple Valley got their shots Wednesday. Some of the monkeys were slated to get their doses after Matilda on Thursday. The wolverine, Rivas said, would likely be among the zoo's most vaccine-wary residents.

At Como Zoo, veterinary technician Andrea Persson is most anxious to vaccinate the snow leopards after three of the big cats, which are considered vulnerable to extinction, died of complications from COVID-19 at a zoo in Nebraska late last year.

The zoo in St. Paul plans to vaccinate roughly two dozen of its animals.

Neither the Como nor Minnesota zoos have documented any cases of the virus in animals to date. Zoo staff say they are careful to wear personal protective equipment to minimize the risk of transmission, and the U.S. Food and Drug Administration classifies the risk of animal-to-people spread as low.

Yet the fast-spreading nature of the virus across species is extraordinary, Rivas said. Researchers have found that COVID-19 circulated widely throughout the U.S. white-tailed deer population — though they do not appear to get sick from the virus — and a recent study suggests that a deer in Canada passed the virus to a human.

"To have a virus that can replicate in a hoofed animal and go back into a primate is really kind of unique," Rivas said. "It's making us rewrite the playbook on how we handle infectious disease."

The various strains of COVID-19 present themselves differently in different species, she added. Gorillas, for instance, have shown respiratory symptoms similar to humans, while gastrointestinal issues were among the first signs of the virus in some tigers.

The disease was devastating to mink, which died by the thousands after outbreaks at farms.

There have also been breakthrough cases documented among vaccinated animals, though veterinarians are hopeful the shots lessened the severity of symptoms. Most zoos have not seen any side effects associated with the shots in animals. Unlike the Pfizer or Moderna vaccines for humans, Zoetis' vaccine uses a viral spike protein to trigger an immune response.

"It's kind of been this big, massive, collaborative scientific effort because obviously we've all had to grow and learn very rapidly as this pandemic evolves," Rivas said.

Many zoo animals have been trained for years to participate voluntarily in their own medical care. Zookeepers establish relationships and teach cues, mimicking the act of giving a shot with a blunt needle or pinch hundreds of times before the actual thing.

Good behavior is, of course, rewarded with a treats (chicken for the big cats, fruit for gorillas, Persson said).

After receiving her shot, Matilda wrapped up a training session with zookeeper Amber Dunaway by nosing a target stick in exchange for more sweet potatoes.

"We'll see you again in three weeks for your second dose," Rivas said as the 8-year-old moose ambled away.