Veterinary use of ivermectin.

Following the development of a unique claim structure encompassing both nematode and arthropod species, ivermectin was first introduced as a veterinary parasiticide in 1981. For cattle(c), sheep(s), horses(h) and pigs(p) injectable(c,s,p), oral(c,s,h) and topical(c) products are available delivering ivermectin at 200 to 500 micrograms/kg. Efficacy extends to nematodes of the gastrointestinal and respiratory tracts, conjunctival sac and soft tissues. Among the arthropod parasites claims have been established for the biting fly Haematobia irritans(c), the screw-worm Chrysomyia bezziana(c), larvae of the oestrid flies Hypoderma spp.(c), Dermatobia hominis(c), Oestrus ovis(s) and Gastrophilus spp.(h), lice(c,p), mange mites(c,s,p) and the ticks Boophilus spp.(c) and Ornithodorus savignyi(c). In the dog two oral formulations are available for the prevention of heartworm disease caused by Dirofilaria immitis by administration of 6 micrograms/kg once monthly during the mosquito season.