Lameness is a problem for many sheep farmers, with an estimated 10% of the national flock lame at any one time. With breeding season upcoming for mid-season flocks, treatment of lame ewes and rams should be completed immediately.

Lame ewes can lose 20% of their body condition score (BCS), which will affect both ovulation and conception, with lame rams unable to mount or reluctant to seek out ewes, leading to ewes being missed or an extended breeding season.

For farmers purchasing in breeding stock, steps should be taken to limit the possibility of bringing lameness into the flock as much as possible.

Causes

An estimated 90% of lameness in sheep in Ireland is attributed to two causes – scald and footrot. The first step to treatment is identification.

  • Scald: Characterised by sores between the sheep’s toes at the back of the foot, no smell and sheep become severely lame very quickly. If the hoof horn is lifting, the hoof is rotting and foul smelling, then it is most likely scald. Scald thrives in damp conditions and is most common from September to March, or in straw-bedded sheds where there is a lack of clean, dry bedding.
  • Footrot: Footrot generally begins between the toes before penetrating the hoof, causing under-running of the hoof wall, with a characteristic foul smell due to the hoof rotting.

    • Similar to scald, footrot is most common in damp, warm conditions such as wet fields or straw bedded sheds, with wet areas around water troughs or feed barriers another environment for the disease to exist.

  • CODD: Contagious Ovine Digital Dermatitis is a less common cause of lameness, but is highly infectious and easily spread throughout a flock.

    • This type of lameness starts at the coronary band (where the hoof and the hair meet). It usually spreads rapidly to under-run the hoof wall.

    It is usually the outside wall of the hoof that is affected. There is no foul smell associated with CODD. It bleeds easily and as the name suggests, it’s contagious and can affect 30%-50% of the flock in a short time.

    Prevention

    There are several areas where farmers can help limit the prevalence of lameness in their flocks. At any one time on the farm, the aim is to keep the number of lame sheep below 5%.

  • Isolate: Separate lame sheep to prevent lameness spreading throughout the flock. Lame sheep should be footbathed every five days until cured.
  • Cull: Cull persistently lame sheep. If a sheep is lame more than three times in the year, despite routine footbathing, she should be marked and culled. Where rams are persistently lame, they should be removed from the flock and not used for breeding purposes.
  • Quarantine: Quarantine all incoming sheep for a minimum of 28 days to avoid the introduction of a different strain of footrot or CODD, as well as for worm burden and sheep scab. Quarantined sheep should be footbathed a number of times before joining the main flock.

    • Treatment

    Footbathing is a highly effective way of treating both footrot and scald in sheep. Research has shown that having good handling and footbathing facilities in place will lead to less lameness, with treatment of lame sheep completed more readily and routine footbathing completed more frequently.

    Ideally, sheep should first pass through a footbath of water to clean their feet. Sheep should then stand in a footbath containing an appropriate solution at a depth of 5cm for a minimum of three minutes.

    Where there is a severe lameness issue, sheep should remain in the bath for up to 20 minutes. When sheep are lame on a particular foot, they will keep it off the ground as much as possible, especially in a footbath.

    Holding them in the footbath for the extended time will ensure that the foot causing the lameness gets adequate time in the solution.

    After sheep have stood in the footbath for the required time, they should remain on clean concrete for up to 30 minutes afterwards to allow the solution to penetrate the hoof before turning back out to grass.

    Where footrot is a persistent issue on-farm, the use of vaccination has been shown to reduce footrot significantly by protecting individual sheep and reducing the challenge on-farm. UK trials have shown them to be 65% effective, so they should be used in conjunction with a normal footbathing routine.

    CODD is not treatable by footbathing, so it is essential to seek veterinary advice for the latest recommendations as soon as CODD is suspected.

    Treatment options include injectable long-acting antibiotics and antibiotic spray, which may require repeat treatment.

    Lameness top tips

  • Isolate bought-in sheep from the flock for a minimum of 28 days.

    Isolate and treat lame sheep.

    Cull persistently lame sheep.

    Stand sheep in footbath solution for minimum three minutes and stand on concrete surface afterwards for a minimum of 10 minutes.