A veterinary drug classed as a chloronicotinyl nitroguanidine insecticide; a topical therapy, usually applied monthly, acts by blocking the nicotinic acetylcholine receptors on the postsynaptic membrane of a receptor class present in insects only; resulting in paralysis and death; an important method of control of fleas in both adult and larval phases; not efficacious against the ascarid worm group.
