Sudden death in calves associated with Strongyloides papillosus infection

In recent years, a total of 152 calves have died suddenly on three farms in the southern part of Japan which used sawdust as litter. Calves often died within a few minutes of a violent fall without showing previous clinical signs. On necropsy of these cases, only a slight lesion was observed, although all showed heavy infection with Strongyloides papillosus (SPL). They appeared to have not only a large number of SPL eggs in the faeces, together with many adult SPL worms in the intestine, but also many migratory SPL larvae in tissues such as the lung and muscle. These outbreaks ceased following medication with thiabendazole or ivermectin. It is concluded that 'sudden death' is associated with heavy infection with SPL.