WASHINGTON – The Food and Drug Administration has approved the first long-term injectable drug to prevent heartworm in dogs.

One injection provides six months of heartworm protection, the agency said Thursday.

The new drug, ProHeart 6, provides an alternative to current heartworm drugs that involve pills taken daily or monthly.

Heartworm is a parasite transmitted by mosquitoes that can be deadly. In its adult stage the worm infects the heart and major blood vessels of the animal.