The tests at the 60,000-strong mink farm started after minks began dying unexpectedly, and the farm now suspects the mink got the virus from an infected worker, its director told local media.
“At this moment the farm is in isolation, but we only told to cull 40 mink who were in close contact with the infected. The rest are under close surveillance and any decisions would be taken as the situation develops”, said a health agency spokeswoman.
Lithuania has 1.6 million mink on 86 farms, she added.
Denmark said last week a new, mutated strain of the coronavirus stemming from mink farms in the country was “most likely” extinct.
All farmed minks in Denmark have been culled because of coronavirus outbreaks among the animals and the discovery of the mutated strain, which authorities said showed reduced sensitivity to antibodies, has caused fears it could compromise vaccines.
Lithuania’s mink herd is vastly smaller than Denmark’s, which was one of the world’s biggest.
France and Poland have found the first cases of Covid-19 in their mink over the past week.