The Toronto Zoo says it will begin vaccinating certain susceptible animals within its facilities against the virus that causes COVID-19.
In a news release, the zoo said it has received 320 doses of vaccine from Zoetis, a veterinary pharmaceutical company based New Jersey, and that staff will soon start immunizing about 120 animals in their care. Each animal requires two doses taken two to three weeks apart, the zoo said.
The specific animals selected for vaccination against COVID-19 were chosen based on a list "developed through on-going research and reports of positive cases" among animals at other zoos around the world.
"The health and safety of our animals is a priority and we will continue to do everything we can to ensure we protect their health," the Toronto Zoo said in the release.
"This includes giving them their regular vaccines from when they are first born, providing them with the highest level of medical care throughout their lives and administering the new vaccines to fight COVID-19 that has proved to be deadly in some animals in other zoos."
The release noted that some zoos in the United States began immunizing their animals against the illness in 2021 and that no adverse effects have been reported to date. Six accredited wildlife facilities in Canada have been approved by the Canadian Food Inspection Agency to administer the veterinary vaccine to animals in their care.
While no positive cases have been confirmed at the Toronto Zoo through the pandemic, animals at other facilities in numerous countries have fallen ill after contracting the virus.
In January 2021, for example, a troop of lowland gorillas at the San Diego Zoo began displaying symptoms of COVID-19 infection. Soon after, the gorillas became the first known apes to have confirmed cases of the illness. The outbreak was linked to a staff member who was infected but had no symptoms at the time of transmission.
Confirmed cases in animals at other wildlife facilities have included tigers, lions, hyenas and hippos, among others. Three rare snow leopards died from symptoms of COVID-19 at a zoo in Illinois last year.
The Toronto Zoo said in its release that staff will use a technique called "positive reinforcement training" to administer the vaccine doses to animals with as little stress and discomfort as possible.
"Many of the animals willingly present an area of the body (such as an arm or tail) as part of their regular training exercises with their trusted keepers, with desirable treats often used as a reward for their participation," the zoo said.
Any potential adverse effects to animals must be reported to Zoetis as part of the manufacturer's agreement with zoos and facilities using their product. The Toronto zoo will also need to provide a monthly report to Zoetis on the vaccine's usage and safety observations. Data will be shared with the U.S. Department of Agriculture, which provided the original experimental use permit for the vaccine to Zoetis.