There has been a gradual increase in the incidence of external parasites, namely sheep scab and lice in recent years. Many farmers and vets point in particular to a higher incidence of lice last winter, as was also the case in housed cattle. Both sheep scab and lice are highly contagious and once they gain entry into a flock, can establish and spread very quickly. Speaking at last week’s Nutrias and Bimeda sheep seminar in Roscommon, Bimeda’s Morgan Lane said that dipping at this time of year is the most appropriate option to treat all external parasites in a single treatment.