Think ticks this late summer
As many of you will be in the process of weaning lambs and starting to think about tupping, or moving cattle onto silage aftermaths, ticks may not be top of your list of considerations,听but the coming weeks and months often see a peak in tick-borne diseases in livestock.听
The highest proportion of听ixodes听ricinus听sheep/deer听ticks are seen between May and July, but in听some areas听with the right temperature and humidity,听they can be present all year round.听Symptoms of tick-borne diseases are usually seen a few weeks after a tick bite from an infected tick,听with the time ticks take to get a blood meal varying by life-stage,听so you may not always find the tick(s) on the affected animal.听
Tick-borne diseases found in Scottish livestock听听
There are three key tick-borne diseases affecting sheep:听
Tick borne fever (TBF)听
Caused by the bacterium,听anaplasma听phagocytophilum, affected animals can experience听immune suppression increasing the risk of secondary infections,听high fever, poor appetite, milk drop,听abortion,听and听temporary听infertility. Cattle can also be affected with TBF.听
Tick pyaemia听
Pre-weaned lambs (2 鈥� 12 weeks old) affected by tick pyaemia show signs of lameness or paralysis, after the bacterium听staphylococcus aureus, enters the bloodstream and produces abscesses in the tendons, joints,听spine,听and brain.
Louping ill听
Sheep affected by听louping听ill, caused by a听virus,听show听neurological signs including hyperreactivity, recumbency, seizures and sudden death.听Young lambs are usually protected from听louping听ill by听colostral听antibodies in endemic听areas but听are at risk if there is a failure of passive transfer of immunity and when听colostral听antibodies wane as the lamb gets older.听There is currently听no听commercially available听louping听ill vaccine on the听market, but听are crowdfunding to change this.听
Ticks can also spread the protozoa,听babesia divergens, to cattle resulting in听babesiosis, also known as听redwater,听due to the production of dark pigmented urine in affected animals. Other clinical signs include depression, high fever, respiratory distress,听diarrhoea,听and death. Calves under one year old appear to be resistant to babesiosis.听
Co-infections with more than one tick-borne disease have been recorded and these cases can be associated with higher morbidity.听
An increasingly nationwide problem听
Traditionally, the greatest risk of tick-borne disease was in upland听rough听grazing听or moorland听areas听in western听Scotland, but听tick-borne diseases have been recorded in听almost all听regions of Scotland in recent years. This has been driven by host availability,听and of听particular interest is the growing number of deer in some locations.听However, sheep can听maintain听tick populations in the absence of wildlife.听
Additionally, changing land use from听agri-environment听schemes, ecological focus areas and forestry expansion has created more suitable tick habitats. Tick distribution varies across fields, but they tend to be concentrated at woodland edges, pasture margins,听water margins听and near areas of bracken. Climate change is also altering tick distribution due to changing temperature and rainfall levels.听听
Tick-borne diseases may be introduced to new areas following the purchase or movement of stock.听
Managing the听risk听
As ticks tend to spend most of their life cycle off the host in thick,听damp听vegetation,听control can be difficult.听Long-term pasture improvement, drainage, scrub听clearance,听and deer fencing听can be used, but this may conflict with the听aims听of some听agri-environment schemes.听Welfare and economic听trade-offs听also exist听between grazing the听high-risk听areas and the provision of听food,听shelter,听and shade.听
To balance this,听high-risk stock (na茂ve animals that have either been听bought听from non-tick areas and听pre-weaned lambs听or听calves) should avoid grazing high-risk pasture when tick levels are expected to be highest听in the spring and autumn. Exposing stock to a low-level tick challenge pre-breeding should help build immunity. It is then essential to ensure exposure is听maintained听to retain this immunity in older stock.听听
Five top tips 听
- When handling livestock for other management tasks, check for ticks. Key areas are on skin folds between the chest and front legs in the groin around the udder or scrotum.听
- Complete a risk assessment of your grazing areas to plan your grazing rotation for high-risk animals at key times of the year.听听
- At the autumn sales, ask vendors what the tick history of their farm and whether the stock being sold has been tick exposed or not.听
- Speak to your local farm vet about听tick-borne diseases and their treatment and integrate this into your health plan.听
- Don鈥檛听forget to check the farm dog or yourself for ticks!听Dogs and humans can also be affected by tick-borne diseases.听
Laura Henderson, Consultant,听Laura.Henderson@sac.co.uk听
Posted by SAC Consulting on 21/07/2026
