Nov 21 (Reuters) - The U.S. Food and Drug Administration

on Friday authorized emergency use of Elanco Animal Health's ( ELAN )

chewable tablet to treat the infestation of a parasite

in cats known as New World screwworm.

Shares of the company were up more than 3% in afternoon

trading.

The agency said it is the first time it has cleared a drug

specifically for this use in cats and kittens. The authorization

allows the drug, branded as Credelio CAT, to be used while U.S.

health officials consider New World screwworm a potential public

health emergency.

The New World screwworm is a parasitic fly species whose

larvae infest open wounds on warm-blooded animals, including

livestock and humans.

Most cats in the U.S. are at low risk of New World screwworm

due to their geographic location, the agency said. Outdoor cats

near the U.S.-Mexico border and cats that have traveled to

countries where the parasite is found are more likely to be

exposed.

Credelio CAT will only be available with a prescription from

a licensed veterinarian. The FDA said professional expertise is

needed to watch for side effects and manage any problems that

arise.

Cat owners should speak with their veterinarian about

whether the treatment is suitable for their animal, the FDA

said.

Credelio CAT was first approved by the FDA in 2019 to

prevent fleas and ticks in cats and kittens.

The drug's active ingredient, lotilaner, is part of a widely

used class of drugs for parasites. While these products are

considered safe for most cats, they have been linked in some

cases to nervous system side effects such as tremors, unsteady

movement and seizures, the regulator said.