On a bad day I can often utter "lousy sheep!" Although that is probably a polite version! Lice and sheep is what I am going to rabbit on about this time, lousy sheep!. I am naturally moving on from the last three postings - Ornate horns, Dancing sheep, and Itchy sheep, we have now progressed to Lousy Sheep.
Lice in sheep is becoming more prevalent in the British Isles, as are other ectoparasite problems such as Sheep Scab - the reason? Well, up until 1992 it was compulsory to plunge dip your sheep in a diluted organophosphate solution. This had been common practice for many years in an attempt to eradicate Sheep Scab from our country.
Our servicemen fought in the gulf war of 1990 and upon their return some complained of something called organophosphate poisoning, which the government swept under the carpet and refused to acknowledge. Shortly afterwards our government deemed it was no longer necessary to have to compulsory dip sheep for sheep scab, even though the problem had still not been totally eradicated from our sheep flocks. There was even a new dip came upon the market, a more user friendly one, a cypermethrin based dip which by chance has now been taken off the market as it has been proven to have adverse affects on the environment. Interestingly enough regulations were brought into force where upon anyone wishing to work with OP dips had to either go on a course (which cost a fair bit of money - I know!) to become certified in the safe use of organophosphate dips or they had to work alongside someone who had attended and passed the course.
So all in all, since 1992 it has no longer been compulsory to plunge dip your sheep. Many were relieved. Hill men continued the tradition but even they got lax as the years went by and less staff were available on the farms. Other products came upon the market, injectables and external 'pour ons' became available. These all made the job far easier. However there is no product available which will control every external parasite on the sheep other than an organophosphate. Those that deal with scab don't cover for lice and vice versa. The most successful option to control external parasites on your sheep flock at the present moment still remains to fully submerge your sheep by plunge dipping with an organophosphate solution, however, it is not always the most favourable.
The conclusion of all this is that sheep lice is becoming a common problem amongst our flocks and sheep scab too is on the increase.
Sheep scab is far more severe than lice, however lice themselves can cause a great deal of trouble to a flock, especially as it seems to get a good hold in the winter months when ewes are in lamb, grazing is poor and life can be tough enough for sheep without ending up being itchy with it.
January to March seems the optimum time for louse infestations in this country, sheep can be carrying lice for a long duration, when they are clipped a high percentage are lost from the body via the fleece that has been removed, the remainder slowly go about their business, until their numbers gradually increase and the conditions on the sheep become favourable to the louse, which seems to be during the winter months. This almost proves the tales I was brought up with of lice 'lying dormant'. The fact that sheep lice only live on sheep and don't survive for long off sheep probably disproves the tale I was accustomed to that they can pick them up from the hay they are being fed on.
Louse activity has been linked with poor health conditions in the sheep. I am apt to question this. I'm not a scientist, or a veterinarian, I have no letters behind my name, didn't go on to higher education so probably am not in a position to speak authoritatively on the matter. However, my observations lead me to question that an under lying health issue may be the cause of lice. There is no doubt that in some flocks it may well be the cause but on Tuesday and Wednesday of this week I found myself in Scotland working with the sheep which I lamb. I haven't seen these sheep since I clipped them, they are running on high ground in the Scottish borders and have had a rough winter (as have many flocks), I was gobsmacked at how fit they were, not just fit but bordering on fat. They were full of life, carrying a lot of fettle and they had lice. I can safely say that in this instance I do not believe poor physical health had any connection with the sheep being lousy.
There is however, no doubt in my mind, that lice can cause poor health. Bearing in mind that the lice seem to multiply and go forth during the winter months and through to early spring. Sheep can find themselves heavily infested if left untreated. Pregnant ewes especially are reaching the later stages of their pregnancy and they are exerting energy scratching, biting and rubbing on, their wool begins to drop out exposing bare pink skin, the weather proof coat is dropping off allowing the cold and wet to get in and chill. Stress. The sheep are finding themselves under physical stress at a time when they need all their reserves to keep themselves and their growing foetus' going, surely this is going to help cause poor health? I believe so.
Regardless, I'm sure that anyone with any pride in their flock will want to treat their sheep should they show signs of scratching and discomfort. Once it is clear in your mind which parasite you are dealing with (should their be any doubt a vet will soon be able to confirm which creepy crawlies are to blame)there are a number of products available on the market to get the problem under control.
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