Ticks can have significant effects on sheep welfare and production, and recent studies suggest ticks are becoming more numerous and widespread throughout the UK.
In sheep, they transmit three important diseases:
- Louping ill - symptoms are wobbly gait, trembling, seizures or even sudden death.
- Lamb pyaemia (“cripples”) - resulting from infected tick bites, can cause lameness, paralysis, ill thrift and death in young lambs
- Tick borne fever (TBF) - causes reduced immunity (respiratory / joint infections) and reproductive problems
Adult ticks will also feed on humans where they can transmit Lyme's disease, a potentially debilitating disease.
Ticks are visible to the naked eye on sheep and lambs.
Lamb infested with ticks
Ticks are generally active from March until October (with peak times in Spring and Autumn) depending on the area and weather.
- Ticks favour dense, damp habitats, eg. rough grazing, heath or woodland. The thicker the vegetation the heavier the tick population.
- Ticks are becoming more abundant due to changes in farming practice, climate change and acaricide resistance.
- Prevention is the best form of control. Ticks can be prevented through the use of synthetic pyrethroid based pour-ons containing cypermethrin such as Crovect® Pour-on, alphacypermethrin or deltamethrin, or a diazinon organo-phosphate based plunge dip.
This guide is a practical introduction to the external parasites most likely to jeopardise the welfare and productivity of sheep: blowfly strike, lice, ticks and scab.