The invention relates to novel liquid formulations suitable for topical administration to animals, which formulations comprise a fluorine-containing antiparasitic active compound and also triethyl phosphate, and to their use for the control and prevention of animal parasites.本發明係有關一種適合局部投予動物之新穎液體調配物,該調配物包含含氟抗寄生蟲活性化合物及磷酸三乙酯,並有關其於防治及預防動物寄生蟲上之用途。