Mink on two farms in Utah have become the first in the United States to test positive for the coronavirus, state and federal officials announced last week. Five animals on the farms tested positive for the virus, but many more are believed to be infected because of a recent upswing in the number of mink deaths on the farms, Bradie Jill Jones, a spokeswoman for the Utah Department of Health and Agriculture, said. Typically, two or three mink die per day on a farm, she said.

Samples from the mink were tested at the Utah Veterinary Diagnostic Laboratory and the Washington Animal Disease Diagnostic Laboratory, officials said. Later, those results were confirmed by tests performed at the United States Department of Agriculture’s National Veterinary Services Laboratories.

Several workers at the two farms have also tested positive for the coronavirus, Jones said, but the department has not determined if those infections are linked to the farm. There is no evidence that animals play a significant role in spreading the virus to humans, according to the federal Department of Agriculture.

Of the 2.7 million mink pelts produced in the United States last year, more than half a million came from Utah, according to federal data. The only state to produce more was Wisconsin, which produced a little more than a million mink pelts.

“Mink were known to be susceptible” to the virus following an outbreak on multiple farms in the Netherlands, the United States Department of Agriculture said in a statement. In June, thousands of mink were killed in Spain and the Netherlands on the suspicion that they may be passing the disease to people.

The mink cases add to a list of species that have confirmed positive with the COVID-19 virus in the U.S. since the pandemic was declared. Other species include cats and dogs — including four cats and two dogs that tested positive in July in Utah — as well as tigers and lions in zoos, according to the U.S. Department of Agriculture.