Cattle louse is a common infectious disease in cattle, which is called bovine louse disease. It is caused by bovine blood louse, bovine E louse and bovine hair louse parasitic on the surface of cattle (mainly on the back, neck, shoulders and tail). Plant ash can kill bacteria, but it can't kill lice. Better isolate it. Then, it is suggested to use traditional Chinese medicine composition for external use to remove lice. The formula of traditional Chinese medicine is: realgar 60g sulfur 60g duckweed 90g Artemisia annua 90g Folium Artemisiae Argyi 100g camphor tree 80g Stemona 90g Datura 30g Gan Song 80g.