This invention concerns a method for the preparation of a suspoemulsion formulation, which can be easily produced on an industrial scale and which allows the reproducible and effective administration of one or more water-insoluble veterinary drugs through water distribution systems. The water-insoluble veterinary drug, in finely ground form, is dispersed in a water immiscible liquid, followed by homogenisation of this system into a water phase. To facilitate the preparation of a stable formulation, one or more stabilising agents such as emulsifiers, thickeners, anti-oxidants and anti-microbials can be used. The resulting suspoemulsion shows excellent long term storage stability and a good “in use” stability after dilution in a vessel and during all handling and transport in the water distribution system.