First documentation of a jaguar (Panthera onca) with otitis caused by Otobius megnini (Dugés 1883).

Otobius megnini (spinose ear tick) is a cosmopolitan soft tick that parasitizes domestic and wild mammals, as well as humans. The larval and nymphal stages are common parasites that feed on blood inside the canal ears of hosts, while adults are nonfeeding and live off the host. Different nymphal stages of O.

First documentation of dose response of Amblyomma cf. parvum population infesting dogs to amitraz, coumaphos, and cypermethrin.

Amblyomma cf. parvum (Ixodida: Ixodidae) is an ectoparasite of domestic animals and wildlife on the American continent. There is little information on the efficacy of acaricides for the control of this tick species in domestic animals.

Monthly fluctuation of parasitism by adult Ixodes keiransi ticks in dogs from Yucatán, Mexico.

The monthly fluctuation of adult Ixodes keiransi in dogs from two cattle farms in southeastern Mexico was determined. In ranch 1 (R1), 6-7 mixed breed dogs from six months to five years of age; while in ranch 2 (R2), 7-8 mixed breed dogs from one to four years of age, were followed. All dogs were monthly inspected for tick infestation through one year.

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.