Evidence of resistance to ivermectin in the gastrointestinal nematodes of horses from Mexican southeast.

Gastrointestinal nematodes (GIN) are a major impediment to breeding and exploitation of horses. Traditional control of GIN has generated resistance to main anthelmintics, including ivermectin. An analysis of five ranches with a history of IVM use was done to determine the efficacy and resistance of GIN to IVM treatment in horses from the Mexican southeast.

Anthelmintic Activity of Extracts and Active Compounds From on and Cyathostomins.

The present study aimed to evaluate the anthelmintic activity of leaf and bark extracts of collected during different seasons and their major constituents on eggs of , and cyathostomins. Specifically, the eclosion inhibition of the methanolic extracts of the leaves and bark of collected during the dry and rainy seasons (600-37.5 μg/ml) were evaluated in addition to the fractions, sub-fractions (300-37.

Rhipicephalus (Boophilus) microplus resistant to acaricides and ivermectin in cattle farms of Mexico.

Ticks and the diseases they transmit cause great economic losses to livestock in tropical countries. Non-chemical control alternatives include the use of resistant cattle breeds, biological control and vaccines. However, the most widely used method is the application of different chemical classes of acaricides and macrocyclic lactones.