Ectoparasites in sheep

Ectoparasites in sheep are a major concern worldwide, as they represent a significant constraint to global food security (Fitzpatrick 2013), through their negative impact on welfare and production, mainly through wool, meat and milk production losses, plus a negative effect on fertility and lamb growth rates. Their chemical treatment and control also account for major costs, with a significant impact on the environment.

There is a long list of ectoparasites that can affect sheep, some have major economic and welfare implications, others are more relevant in specific geographical location or in relation to the system of production (Colebrook and Wall, 2004; Cortinas and Jones, 2006).

The main ectoparasites (in alphabetical order) for sheep are:

Among all the listed diseases that are related to ectoparasites, some are particularly relevant in the UK. To find out which diseases are common in a particular area, the surveillance tool developed by Animal and Plant Health Agency (APHA) can be used (https://public.tableau.com/app/profile/siu.apha/viz/SheepDashboard_/Over-view). The tool indicates the main diagnoses in a particular area. As per autumn 2021, the most diagnosed ectoparasitic diseases across all ages in the UK were: sheep scab; pediculosis; tick-borne disease; and blowfly strike.