Sheep scab is rife across the country and there has been a recent awakening about this problem on a grand scale.

Farmers who previously had “a few itchy ewes” or “a wee touch of lice, the vet said” are having to confront this terrible illness.

However, the fact that it is a notifiable disease has done us all no favours, because it has merely served to stigmatise the condition – the fear of becoming an agricultural ‘pariah’ means that, for years now, people refused to talk about it.

Rumours that a reported case results in complete flock shutdown by DAERA officials has also been far from helpful and a fantastic assister in helping to keep the spread consistent.

So let’s just say I have a “friend” who has had to confront the sheep scab demon, and he recently felt able and willing to discuss the issue with me.

He is one of those 60-something year olds, with grey hair and slowly rotting teeth. I would not describe him as much of a farmer: you are likely to find him leaning on a five-bar gate, gossiping with his neighbours and trying as hard as possible to avoid hard work.


About a year ago (he tells me), he noticed a couple of elderly rams rubbing on ring feeders, and he thought no more about it.

Then, after the pregnant ewes were housed in the run-up to lambing, he saw a few of them rubbing against feed troughs.

However, he did not think about sheep scab because he had been led to believe it was much more instantly contagious and this condition on his farm appeared to spread very slowly.

His wife pointed out how itchy the sheep looked, but he told her to stop talking nonsense, as he is an incredibly thrawn character.

However, after the ewes and young lambs were put out to grass, he had to admit that there was far too much wool stuck around hedges and fences, and perhaps his wife was a bit more astute than he’d given her credit for.


Dectomax was therefore used as a dual-purpose tool to control stomach worms and also to hit the sheep scab on the head (even though it maybe wasn’t scab).

He also realised that he was probably only keeping a lid on the whole issue, because Doramectin requires sheep to be treated, then returned to a field that hasn’t had sheep in it for 17 days, as the scab mite can live for about 15 days on posts and hedges, etc.

In one respect, he was absolutely correct, because it sort of controlled everything very well, to the extent he thought he had eradicated it. But it turns out he was wrong.

Batch treatment

One very itchy lamb was spotted in late July, which necessitated batch treatment with 1% Cydectin. With two injections – 10 days apart – to contend with, along with lambs being presented for slaughter, withdrawal periods proved to be tricky.

Before treatment, fat lambs had to be weighed and selected for the abattoir, then anything that was injected had to stay where it was for 70 days. The reason for using Cydectin was that it meant he could leave the stock on the affected areas.

As an aside, he mentioned that if you leave lambs on good grass for 70 days, boy, can they put on some weight!

I asked my “friend” where things stood now, and he reported that once all lambs had been sent to the factory, he spoke to his vet because he noticed some sheep with the tell-tale early signs of muddy necks (contrary to popular myth, scab seems to start in the ears and ewes reach up with their back legs to scratch the head and neck area).

His vet, without hesitation, told him to treat all stock on the farm with Cydectin LA 2%, as it was persistent, and intimated that other products were not as effective.

Apart from the price (£1.70/head) the 104-day withdrawal can prove bothersome; but it was an ideal time to be using it, as stock sales are done until next year.

When I asked him if he had eradicated the scab on his farm, he said he hoped so, and was quietly confident that it had gone away.


I then enquired about the anecdotal stories around the country concerning the efficacy of the injectable products.

I have heard rumours that dipping is the only means of controlling an outbreak of sheep scab.

Like me, he wonders if a lot of the injectables have been used incorrectly, although he is keeping an open mind on the subject and still has the option of using a contract dipper if scab recurs on his farm.

Overall, he said it has been a stressful time, and he wishes he had taken it more seriously at an earlier stage.

I agreed with him and thanked him for sharing his knowledge with me - it has been an education. I hope my sheep don’t get it.

Importance of product choice

Possibly the biggest issue in dealing with sheep scab is product choice, withdrawal periods, and ease of administration.

My “friend” suspects that some farmers have mistakenly thought they had a “wee touch” of scab, and a simple injection of Ivermectin or Doramectin would make the problem disappear.

It seems feasible that not all of them realised the importance of taking veterinary advice regarding whether or not stock could remain in the same fields or need to be put onto clean pasture (as in, a field that had not carried sheep for 17 days).

And assuming current vet advice is correct, and Cydectin LA 2% is the best option (apart from dipping), the 104-day withdrawal combined with the administration route is a real barrier.


Compared with either a neck muscle injection (Dectomax) or jabs below the skin (Ivermectin or Cydectin 1%), this more effective cure must be injected into a small pocket of fat behind and below the ear.

This is not an easy option. My “friend” reckons you could have three animals jagged in the neck in the time it takes to successfully restrain one sheep, while you try to avoid hitting her in the jawbone with the needle.

An unwanted Christmas gift

At the end of the day, the real crux of this issue is that, assuming you have successfully eradicated sheep scab from your farm, it has not been removed from the area.

This means that once your flock has reached the end of the persistency of the chemical used (from zero to 60 days), they are susceptible to re-infection.

Therefore, if your neighbour has itchy sheep on the other side of a wire fence, you are back to square-one again.

That’s not a very nice Christmas present to be giving anyone, is it?

Read more

New code allows for sheep shower clampdown

Survey finds 36% of NI flocks had sheep scab