Tick-borne diseases including louping ill and tick pyaemia cause significant mortality and welfare compromise in sheep flocks on tick-infested upland and woodland pastures.
Tick-borne diseases cause significant and often severe welfare harm in affected sheep. Louping ill causes acute neurological disease with progressive ataxia, trembling, and collapse, ending in death in a significant proportion of affected animals without recovery. Tick pyaemia causes multiple abscesses in lambs' joints, muscles, and internal organs, creating a chronic, painful condition from which full recovery is rare. The neurological impairment from tick-borne fever causes behavioral abnormalities and immune suppression that predisposes to other diseases. Sheep with severe tick pyaemia face a welfare trajectory of progressive deterioration from multiple abscesses causing ongoing pain and disability.