Ramil "appears to be doing well" and has been quarantined with a female snow leopard and two Amur leopards who share a space with him and, as such, are considered close contacts.
"We can assure you the snow leopard and the Amur leopards who share his habitat are receiving excellent care," said Dwight Scott, the zoo's executive director, in a statement.
"Our veterinary teams and wildlife care specialists at both the Zoo and Safari Park are highly skilled, dedicated professionals who work tirelessly to ensure the well-being of the wildlife in our care," he added.
San Diego zoo has received a donation of "recombinant purified spike protein vaccine" that is said to protect animals against Covid-19.
Ramil had not received it yet.