Sheep lameness can cause severe problems in many flocks and understandably remains an area of concern for many shepherds and smallholders. The change in weather towards milder winters and wetter summers means the prevalence of lameness has increased. In the past few years there has been growing evidence that lameness should be managed by methods that contradict the traditional approaches which can lead to confusion so we hope that this article can help clarify the approaches to treatment and prevention.
The most common causes of lameness are footrot and scald. These are both infectious diseases caused by Dichelobacter nodosus which means that just trimming lame sheep will not only fail to treat the problem but will also spread the bacteria between sheep.
Scald is the milder of the two diseases as it simply affects the skin in the interdigital space - causing redness, swelling and some white exudate. It can often resolve on its own especially if dry underfoot conditions are provided; otherwise spraying with oxytetracycline spray can assist healing.
Scald can progress to footrot if the horn becomes under-run, classically this occurs at the base of the interdigital cleft but if left to develop then it can spread up the wall and around the hoof. It causes severe lameness and weight loss as it is extremely painful. Footrot is associated with a foul-smelling odour and swelling. Footrot treatment also involves antibiotic spray combined with a long acting injection of oxytetracycline. Under no circumstances should the hoof be trimmed as it is highly contagious; if the sheep has particularly overgrown hooves the ends can be trimmed a week after antibiotic treatment. It is also important to separate any affected sheep to contain spread of disease.
Contagious Ovine Digital Dermatitis (CODD) can be difficult to differentiate from footrot so please consult us if you are unsure. Typically it affects the coronary band and the skin just above it but not the interdigital space. In severe cases the damage to the corium of hoof can lead to permanent problems with regrowth. CODD is most commonly brought onto farm by purchased sheep so strict quarantine protocols (described below) should be observed. Treatment is similar to that used for footrot.
Excessive trimming should be avoided as it can causes toe granulomas where a lump of tissue resembling a strawberry appears at the toe of the hoof, this creates and entry point for D.nodosus which will exacerbate the problem! Anti-inflammatories can help with the pain but often there is no cure the toe granuloma and the sheep may need to be culled.
Shelly hoof appears to occur if there is a nutritional imbalance and affects certain breeds or even breeding lines of sheep although the exact cause is currently unknown. The sole horn separates from the wall horn causes an air pocket with severity varying from a small area to loss of the whole hoof wall. Often sheep will only show signs of lameness once the air pocket fills up with soil or stones. This is one cause of lameness where conservative trimming can be used combined with clearing any debris out of the pocket. If your flock seems particularly prone to shelly hoof it would be prudent to assess their nutritional status as well as establishing if there is a particular family line that appears more prone to the condition.
Sheep lameness is not only a welfare problem but can also have a severe economic impact which is estimated at around £5/lamb or £7/ewe. It is therefore prudent to follow our helpful tips to try and reduce the level of lameness in your flock:
Consider footrot vaccination if this disease is a particular problem:
Quarantine all replacements for three weeks. During this time ensure you:
Quarantining is also useful to identify and prevent any other diseases such as mites and worms!
Treating and controlling lameness requires good observation and rapid intervention. Please don’t hesitate to get in touch if you have any concerns about the level or type of lameness affecting your flock.