This invention relates to a method of controlling the spread of dirofilariosis, such as for example heartworm, by administering to at least one non-human animal infested with filarioid nematodes such as Dirofilaria spp or susceptible to have been infested with filarioid nematodes such as Dirofilaria spp, an effective dose of a combination of a neonicotinoid compound and a pyrethroid compound.
