Biomaterial Database

Efficacy of ivermectin against naturally acquired and experimentally induced nematode infections in sheep. 1982

R B Wescott, and B R LeaMaster

The activity of ivermectin against common nematode parasites of sheep was examined in 2 experiments. In the 1st experiment, 14 sheep with naturally acquired infections were assigned to 2 groups of 7 sheep each. Sheep in 1 group were treated with 200 micrograms of ivermectin/kg of body weight and the remainder served as nontreated controls. In the 2nd experiment, 15 sheep with experimentally supplemented infections (including a benzimidazole-resistant strain of Haemonchus contortus) were assigned to 3 groups of 5 each. The 1st group was treated with 200 micrograms of ivermectin/kg, the 2nd was treated with 88 mg of thiabendazole/kg, and the 3rd served as nontreated controls. Ten to 12 days after treatment, all sheep were euthanatized and necropsied, and the parasites they harbored were recovered and identified. Efficacy of ivermectin was excellent (greater than 96%) against Dictyocaulus filaria, H contortus, Ostertagia circumcinta, Marshallagia marshalli, Trichostrongylus axei, T colubriformis, and T vitrinus. Treatment was not as uniformly effective for Nematodirus spathiger (73% to 85%), N filicollis (80% to 96%), Cooperia curticei (92% to 100%), immature nematodes (92% to 100%), and early 4th-stage larvae (46% to 100%). Efficacy of thiabendazole was poor for H contortus (42%) and early 4th-stage larvae in the abomasum (52%), but approached 100% for most of the other parasites.

UI	MeSH Term	Description	Entries
D007559	Ivermectin	A mixture of mostly avermectin H2B1a (RN 71827-03-7) with some avermectin H2B1b (RN 70209-81-3), which are macrolides from STREPTOMYCES avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other CHLORIDE CHANNELS. It is a broad spectrum antiparasitic that is active against microfilariae of ONCHOCERCA VOLVULUS but not the adult form.	Eqvalan,Ivomec,MK-933,Mectizan,Stromectol,MK 933,MK933
D007783	Lactones	Cyclic esters of hydroxy carboxylic acids, containing a 1-oxacycloalkan-2-one structure. Large cyclic lactones of over a dozen atoms are MACROLIDES.	Lactone
D009349	Nematode Infections	Infections by nematodes, general or unspecified.	Infections, Nematode,Infection, Nematode,Nematode Infection
D002986	Clinical Trials as Topic	Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.	Clinical Trial as Topic
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000969	Antinematodal Agents	Substances used in the treatment or control of nematode infestations. They are used also in veterinary practice.	Nematocides,Antinematodal Drugs,Antinematodals,Agents, Antinematodal,Drugs, Antinematodal
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli
D012757	Sheep Diseases	Diseases of domestic and mountain sheep of the genus Ovis.	Ovine Diseases,Disease, Ovine,Disease, Sheep,Diseases, Ovine,Diseases, Sheep,Ovine Disease,Sheep Disease