In the treatment of a case where the parasite is already present, for two days previous to the employment of a vermifuge a light diet should be given and the bowels moved by a purgative.
At one time they were supposed to be useful as a vermifuge.
The rue and wormwood are in general use as domestic medicines - the former for rheumatism and neuralgia; the latter in fever, debility and dyspepsia, as well as for a vermifuge.
The powdered bark is sometimes given to horses as a vermifuge; it possesses likewise tonic and febrifugal properties, containing a considerable amount of salicin.
In autumn all horses that have been grazing should be dosed with some vermifuge to destroy the worms that are invariably present, and thus prevent colic or an unthrifty or anaemic state.