Best treat whole flock for footrot
WHEN dealing with footrot, the whole flock needs treating, says Diane Spence.
The disease is caused by two bacteria working in tandem: Bacteroides nodosus, which only survives for 10 days on pasture and bedding, and Fusobacterium necrophorum.
To cause lameness they require moisture and a temperature of at least 10C. "This is why footrot is often associated with housed ewes," explains Ms Spence.
"It is a very infectious disease which is very painful, so reducing performance," she said. "Just treating individuals is no good – it is a whole flock problem. Some animals are not curable, so these ought to be culled."
"The best time to treat is just before you are likely to have an outbreak, such as prior to housing or post turnout.
"That way you can pre-empt a high risk time," Ms Spence suggested at the recent ADAS Rosemaund open day.
Footbathing is considered the best strategy for lameness control. Ms Spence recommends a 10% solution of zinc sulphate, rather than formalin. The former is more farmer and sheep friendly than the latter.
"The practical problem with zinc sulphate is that you need to keep sheep in for about five minutes and this is a problem where there are no suitable handling facilities," she said.
Through clean water
To be as effective as possible, ewes should run through clean water before the footbath to remove mud and dirt.
And after treatment they need to stand for a good two hours on dry ground, rather than going straight out onto wet pasture or back into the lambing shed.
In cases where footbathing is impractical Ms Spence recommends producers set up a "sin bin" for lame ewes. "Pare their feet and spray with oxytetracycline spray," she said. "Clean" sheep should not go into that area for at least 14 days after ame ewes have been removed to stop cross infection.