The Cincinnati Zoo said 80 of its animals received two doses of a Covid-19 vaccine designed for veterinary use.
In a press release on Monday, the zoo said it had vaccinated big cats, great apes, red pandas, goats, giraffes, river otters, skunks, bear cats and some domestic dogs and cats.
The zoo said technicians and zookeepers worked for weeks to make sure that the animals “were comfortable with everything they would see and feel if they were given the injections,” and that most were given without anesthesia.
The zoo’s animal health director, Dr. Mark Campbell said in the press release, “We were concerned that the new memory of the first injection would make the animals less willing to offer a shoulder or thigh for the second round, but they did!”
Campbell said the success was “100% due to these animals’ strong relationships with caregivers and our animal health team.”
The remaining animals will receive their second dose in the next two weeks, the zoo said.
Since the beginning of the coronavirus pandemic, Covid has spread among certain mammals such as big cats, great apes, and minks in zoos and farms around the world.
At the end of last year, Denmark killed 17 million minks after outbreaks and virus mutations were reported in more than 200 fur farms.
Last month, the Washington, DC National Zoo found that nine of its big cats were infected with the coronavirus after showing symptoms such as coughing, sneezing, and lethargy. It was said that endangered animals would soon be vaccinated.
Atlanta Zoo reported an outbreak among a troop of western lowland gorillas last month.
The experimental veterinary vaccine used in Cincinnati and other US zoos is made by Zoetis, one of the largest animal pharmaceutical companies in the country.
Christina Lood, a spokeswoman, said the company’s scientists started work on a veterinary coronavirus vaccine “immediately” after Hong Kong reported infections in dogs at the start of the pandemic.
Lood said it was the outbreak in Danish mink farms that caused the Ministry of Agriculture, which regulates veterinary vaccines, to become aware of it.
“The USDA said, ‘OK, now we might want a mink vaccine, so we switched to mink last fall and the San Diego Zoo was kind of watching all of this,” she said.
Following an outbreak among gorillas in San Diego earlier this year, the zoo applied for experimental access to the Zoetis vaccine. Lood said Zoetis donated its leftover doses from previous safety studies and that the zoo administered them to nine of the great apes in March.
The vaccine was generally well tolerated by animals, Zoetis reported, but the coronavirus has spread among zoo animals in San Diego and around the world.
In July, the San Diego Zoo reported that an unvaccinated snow leopard tested positive for Covid after showing symptoms.
By the summer, following more coronavirus outbreaks in zoo animals, Zoetis said it had received even more requests for access to its experimental vaccine and it was making a new batch, the first of which went to the Oakland Zoo in late June, said Lood.
Isabella Linares, a marketing officer for Oakland Zoo, said that of the more than 100 animals classified as “endangered” by specialists – including primates, big cats, river otters and bears – 37 are still in need of vaccination.
One reason why not all animals have been vaccinated is “voluntary participation,” said Linares.
“The tigers are voluntarily trained to show their backs to us so we can give them the vaccine,” she said, saying most had already been trained on it from previous vaccinations. But she said some animals, like one of the zoo’s leopards, need more time to learn.
Only one animal at Oakland Zoo, a brown bear, had side effects after vaccination – tenderness at the injection site – and none of its vaccinated or unvaccinated animals tested positive for the coronavirus.
“We’re really lucky,” said Linares, noting that an unvaccinated African lion recently died at the Honolulu Zoo after testing positive for the virus.