PROCESS FOR THE TREATMENT OF SHEEP TO CONTROL INFESTATION BY EXTERNAL PARASITES

摘要

The invention concerns a process for treating sheep to prevent or reduce the incidence of infestation by external parasites; such as sheep blowfly, sheep ked and lice, by applying an effective amount of a composition containing as active ingredient, the compound of the formula: IMAGE The process is especially effective in preventing fly-strike in sheep as the compound of formula I combines the properties of long persistence on the fleece and high activity against susceptible and resistant strains of flies of the Lucilia spp. A method of preparing the compound from a halogen substituted aryl-acetic acid ester and a phosphorodithioate salt is disclosed.