Sheep producers continue to underestimate the growing problem of disease and worm resistance when buying in sheep. And it’s a massive problem that’s getting worse, according to vet Matt Colston, of Frame, Swift and Partners, Penrith.
“Sheep farmers can no longer afford to take risks with bought-in sheep – and that includes rams. We are supposed to be adopting a strict health policy in UK flocks, but in many cases the risks farmers are taking make it look more like biopromiscuity rather than biosecurity,” he says.
A range of diseases such as footrot, worm resistance, sheep scab, lice, caseous lymphadenitis (CLA) and maedi visna can all be introduced, but putting in place a system to avoid these problems isn’t difficult. “Quarantine is the key,” says Mr Colston. “And it has to be for a full two weeks to ensure it achieves the health protection required.
“The first job is to worm bought-in sheep. They must be held on hard standing for the first 48 hours of the quarantine period to ensure they don’t infect any pasture. They need to be quarantine-drenched according to SCOPS recommendations and then turned out on to a “dirty” pasture that has previously grazed your own sheep.”
All sheep should be penned and checked, and run through a footbath. Any problems that need to be dealt with should be tackled at this stage so any “problem” sheep can be monitored during the quarantine period or referred back to the vendor or auctioneer.
Any sheep with obvious signs of footrot or digital dermatitis should be treated and kept separately from all others – including the ones they arrived with. All sheep should be individually checked again after one week of the quarantine period and again after two weeks before they are allowed to run with the main flock.
“During the quarantine period all bought-in sheep must not be allowed to come into contact through a fence with the farm’s existing flock – that’s crucial. Routine dipping for scab is advised, but any sheep seen scratching must be isolated.
“And look for any tell-tale signs of CLA which will appear as abscesses on the shoulders. Any sheep with this disease must be isolated and returned to the vendor.
And don’t assume that maedi visna is only a pedigree sheep problem, adds Mr Colston. “It’s worth considering blood-testing commercial breeding ewes that are bought in as an insurance against introducing this disease into the flock.
“If, in the future, you do identify a sheep suffering from maedi visna in the flock, you will then be at a stage where at least 60% of the flock is infected – so it’s worthwhile blood-testing,” stresses Mr Colston.
Sheep returning from shows – or those brought back unsold from a market – must be treated as “incomers” and not allowed contact with the rest of the flock. “Health issues like worm resistance and CLA are now major risks and are easily introduced.”
Rob Wilson Scales Farm, Berrier, Penrith
Cumbria sheep farmer Rob Wilson runs about 1000 Lleyn ewes at Scales Farm, Berrier, Penrith, and buys in about 240 replacement shearling ewes every year.
They are bought from a limited number of sales, in large batches from the same vendor whenever possible, and undergo a strict health-check routine once they arrive home.
“When ewes arrive home they are treated with two wormers, one moxidectin and one levamisole and left in pens for 48 hours,” explains Mr Wilson. “We then turn them out on to pasture that has already been grazed by our own sheep, but they remain there – totally out of contact with our own flock – for two weeks.”
Bought-in sheep are not routinely dipped, but are run through the footbath. All are vaccinated to give lifetime cover against abortion. “By adopting the quarantine period and the worming policy we’ve avoided bringing in any worm resistance.”
And Mr Wilson is just as strict about the way bought-in tups are treated. “It’s easy to isolate them. They get the same treatment as the ewes and we also semen-test them.
“All we’re doing is following the advice we’ve been given and it’s working because we’re effectively screening for any health issues before they get chance to get a grip on our existing ewes. We’ve been advised to undertake faecal egg counts at the end of the two-week quarantine period but at the moment we aren’t going that far – yet.
“I don’t want to buy-in worm resistance. We’ve got a lot of sheep here and we haven’t got the spare land to provide clean grazing. So tackling the health status of the incoming ewes is by far the cheapest way of keeping ahead of worm resistance and foot problems.”