The U.S. Food and Drug Administration has authorized the emergency use of an over-the-counter drug to treat New World screwworm infestations in dogs and cats as officials work to contain the parasite's spread in Texas, New Mexico and other affected areas.

The FDA announced Thursday that it issued an Emergency Use Authorization for generic Nitenpyram Tablets, allowing the drug to be used to treat New World screwworm infestations, known as myiasis, in dogs, puppies, cats and kittens that are at least 4 weeks old and weigh at least 2 pounds.

The authorization marks the first generic animal drug approved for use against the parasite.