Lameness presents a highly significant cost to the sheep industry. Controlling lameness is a major cost burden on farmers in terms of their time, the money they spend on products to treat or prevent the condition, along with the losses that they incur throughout the year. It is estimated that the total losses from foot-rot alone, are significant enough to greatly effect farmer’s margins.
There are a number of causes of foot lameness in a flock of sheep. The farmer’s effective management of lameness, depends on correct identification of the problem. The two main causes are:
There will be a red/pink inflammation of skin between the hoofs, with a white/grey pasty scum on top. Sometimes, depending on how far it’s progressed, it can have a very strong smell. Sheep can become very lame with only minor lesions, however, greater lesions will lead to sheep being unable to put their foot on the ground. Scald is an early presentation of foot-rot.
Scald is caused by the bacterium Dichelobacter nodosus which is also a cause of foot-rot. The Infection that causes scald occurs through damaged skin.
Damage can occur through:
- Abrasions/cuts, harsh/rough pastures, thorns, thistles, hedge trimmings or stubble.
- Prolonged exposure to moisture, causing skin to soften.
Scald is most likely to occur when sheep are at a high stocking level. In addition, it is also likely to happen when ewes are with lambs. The transmission of this infection is more likely if there are specific areas where sheep gather together, such as feed troughs, areas of shelter in a field or housing.
In a situation where a farmer has no foot-rot but there is scald present on the farm, then the treatment of individual ewes and lambs with antibiotic spray, is a good procedure.
If there is a severe case of scald present on the farm, then treating adult sheep with antibiotic injection and antibiotic spray is the correct course of action. In cases where incidences are high, sheep should use a footbath and then be moved to a pasture that has been sheep-free for two weeks, if possible.
Farmers have found that by controlling scald in ewes, it has reduced levels of scald in lambs.
Regular foot bathing can help prevent it and in turn, control early outbreaks in lambs if done correctly. It is recommended to use a footbath as soon as lambs are strong enough to go through it. Sheep must stand on a clean, dry, hard area after foot bathing for at lease 30 minutes in order for this process to be effective.
Farmers need to avoid putting lambs on heavily-contaminated faecal areas. Reducing the amount and duration of handling events and improving underfoot conditions wherever possible can also reduce the spread. Lime should be spread around creep feeders, water troughs and gateways.
There will be a grey, oozing puss, with a distinctive foul smell.
A separation of the hoof horn will take place, starting in the inter-digital space. Once established, the sole horn and outer wall horn may be under-run.
Foot-rot, such as Scald, is caused by the bacteria Dichelobacter nodosus which lives on the feet of sheep.
The bacteria that causes foot-rot can survive for a couple of weeks on pasture. The infection is most likely to spread during warm, moist conditions in spring and autumn, even though wet summers and mild winters may create a year-round problem. Infections are highly likely to spread throughout housed sheep, where the bedding is warm or heated and stocking rates are high. It can regularly spread from the ewes to lambs during the summer months, where it can start as scald and develop into foot-rot.
When a farmer identifies the disease they must treat it immediately:
Give a long-acting antibiotic injection (discuss with the vet) for the appropriate weight of the animal.
Apply antibiotic spray.
Do not foot-trim, as this increases the healing time, as well as increases the chance of it returning.
Isolate sheep where possible, and keep them away from uninfected sheep.
Good flock management will reduce the risk of further cases.
Farmers should implement a prevention plan.
Farmers should not breed replacements from sheep with a history of lameness.
Cull sheep that have foot-rot more than twice, as they are passing it on to others.
Consider vaccination before high risk periods, e.g. housing periods.
Treat sheep that even are mildly lame as soon as possible to prevent spread.
Avoid spreading infection.
Isolate incoming sheep for at least 28 days and give a foot-bath on arrival.