[DartmoorLiz]

Why is it that we are told not to routinely worm adult sheep (so I don't) but when I get the vet in to look at why my sheep are not doing well the first thing they recommend is a blanket course of wormer? (FEC result was high for ewes and very high for their lambs).


Did the vets invent SCOPS just to increase their profits?


Next they'll tell me to put them back out onto dirty ground.


And after that they'll tell me that what I do with my 50 ewes really will make a difference to the national flock's resistance to wormers and resilience to worms.


What do other small(ish) flock owners do?

[Rosemary]

Um, your vets are not recommending blanket worming of your sheep - they are recommending worming in response to a high FEC. Blanket worming, in my book, is routine worming without checking to see if the sheep actually need wormed.

This is different to rotating wormers, although with teh same purpose of reducing the spread of wormer resistence. We rotate wormers through the different groups, white, yellow, clear, to stop a build up of worms resistnt to a particular chemical. No wormer kills all worms - usually about 95 - 97% - but if you use the same wormer every year, the 3-5% that aren't killed in year 1 ie that are resistant, will become more numerous in the population.

We worm adult sheep (ewes, tup, wether and any retained hoggs) once a year at lambing, when the stress of pregnancy reduces the ewes' immunity to worms and you get a flush of worm eggs. Worming at this time reduces the worms on grass that can subsequently infect your lambs. We do the hoggs again in preparation for tupping in October. The lambs we worm if required by FEC. If there's a risk from Nematodirus, I do them with a white wormer.

We rotate wormers annually. This year we're on yellow, I think.

Advice now is to put wormed sheep back on to dirty ground so that any resistant worms have to compete - if you put newly wormed sheep on to clean groud, only resistant worms will be excreted on to taht pastrure and will have no competition.

I agree with your vets. I'm not really sure what your problem is with their advice.

[DartmoorLiz]

Thank you Rosemary.  You are right, of course. 


I think what got my goat was that I did not think of worms myself.  I got the vet in because I wanted them to take blood tests to check for deficiencies - all useful stuff but with hindsight I missed the most obvious likely cause for unthriftyness.  I asked the vet to collect samples as a bit of a "while you're here" job.  Glad I did.  Every day is a school day. 

[landroverroy]

 Ok - so you asked what other sheep farmers do. . . .
 I worm my ewes and lambs regularly while they are together as to me it is too late once you've got a high FEC count as you have already lost the bloom on your lambs. So I worm them every 4 to six weeks, as I move them onto fresh grass. I don't put them onto old grass once I've wormed them unless I'm not actually moving them at that time. I rotate wormers, and also cross graze with cattle and donkeys. Quite honestly I don't care about resistant worms competing with non resistant worms, or whatever this decade's theory is, which proves we've been doing it wrong for the last 50 years. The system works, my lambs grow well, and I usually get April born lambs off fat to market in August, straight off their mothers, and I don't have any evidence of wormer resistance.
 After the lambs have gone I worm the ewes again prior to tupping in November, and again just before lambing in April.

[Rosemary]

I don't have any evidence of wormer resistance.

How do you know?

[Womble]

The system works

......until it doesn't.  That's what the new fangled guidance is all about - trying to keep our currently available wormers working for us all for as long as possible.


Always using the same wormer, and moving wormed sheep straight onto new grass is bound to result in higher levels of wormer resistance and faster. Since we only have so many tools available, surely that's something we should all be working hard to prevent?

[Tim W]

Here's another farmer view

Here, if an adult sheep needs worming it needs culling
Anthelmintic resistance is growing and will catch up with all of us one day so it's best to delay that day if at all possible
If we don't manage to self regulate anthelmintic use it will become a prescription only drug

We select and breed for worm resistance and have made considerable and measurable progress...our ewes in the top 25% for worm resistance only shed 1/2 the worm eggs that the bottom 25% of ewes do ( and our ewes shed many less eggs than most other sheep)
We know all the above because we measure and record everything

Every time you use an anthelmintic you increase the parasites resistance   

But anthelmintics are easy to get so farmers use them routinely (although some are getting better ) and farmers are slow to learn , they love to say ''it worked for my pa and so it must work for me''

rant over (maybe)

[landroverroy]

I don't have any evidence of wormer resistance.

How do you know?

The same way they found out originally when wormer resistance was first identified - the wormer doesn't
work any more and your stock just don't thrive, especially the young stock.
 I saw it in the Yorkshire Dales in the early seventies. The farmers used to use a lot of levamisole (yellow wormer) because it was cheap and possibly it might have been one of the first developed that wasn't likely to kill your animals as well as the worms. Then it just stopped working in a big way and so they changed to white wormers (panacur type) and suddenly the stock were thriving again.
 I actually had a problem myself with Panacur about 20 years ago. I used to buy 10% for my sheep as I had a low dosage worming gun. The firm I bought it off used to buy it in bulk and decant it. So I bought this unlabelled stuff, used it as I normally did, and my lambs started scouring, lost condition and looked all potbellied. I consulted my supplier and he said there was nothing wrong with the wormer. Then a couple of weeks later he called me over and said he'd found out the problem - he'd bought 2.5%  panacur by mistake, so I'd been underdosing my lambs by a factor of a quarter. Anyway that year's crop never regained their bloom and I had to sell them as stores, not fat. And I had to rethink my worming routine to overcome the worm resistance caused by underdosing.

 

[pharnorth]

I am routinely worming after lambing in March, after weaning (ewes and lambs) in July then an FEC about now. I'm struggling to rotate pastures as much as I would like because it is so dry here they are not refreshing at all May through to September. Hopefully this way I will have a database of FEC results all done about the same time of year so should spot any resistance.

There is no where near as much Animal Health drug development happening in the UK as there was 30 years ago when these products were developed.

[Tim W]

I am routinely worming after lambing in March, after weaning (ewes and lambs) in July then an FEC about now. I'm struggling to rotate pastures as much as I would like because it is so dry here they are not refreshing at all May through to September. Hopefully this way I will have a database of FEC results all done about the same time of year so should spot any resistance.

There is no where near as much Animal Health drug development happening in the UK as there was 30 years ago when these products were developed.

To identify anthelmintic resistance you need to do a FEC after you have drenched to see if the drug has worked---

[fsmnutter]

I don't have any evidence of wormer resistance.

Yet.
The reason science comes up with new ways of doing things is because we learn from our mistakes.
We used to amputate legs with a saw and no anaesthetic.
Just because worming and moving to clean grass has worked for 50 years does not guarantee it will continue to work next week or that it's the best we can do for ourselves, our stock and our land.
Every parasite, bacteria or virus that is treated with medication is trying to evolve resistance, and some will manage it, and every time a population of worms is exposed to wormer, especially when using them as described by landroverroy (and used by very many sheep farmers), blanket treating everything and moving to fresh pasture, the population of worms gets a little more resistant. Once a certain percentage of worms are resistant (which could be next time they are treated, or years away, without doing worm resistance tests no-one will have any idea how close you are) you'll start noticing a failure of treatment, mucky bums and lost condition but it's too late then, and another class of wormers will be needed, but if continuing the same worming regime, there will soon be resistance to the next class of wormers and so on til they're all gone.
We recommend the new science to try to prolong the life of the classes we do have, slowing down the worms ability to develop resistance, because it could be many decades til we can develop any new wormers.
Another point from Rosemary's post is that changing class of wormer from year to year also speeds up resistance as the worms will develop a little bit of resistance to the class in use that year, but not lose the resistance to the previous class of wormers, so will quite quickly be resistant to more than one drug. Instead it is advised to follow the guidelines on scops and use one class of wormer as advised until resistance shows (which may be decades away if used as carefully as possible) then use another class to which they show no resistance.
Dartmoor Liz it sounds like your vet is being thorough, checking faecal samples and advising worming based on egg counts and I hope this helps your sheep.
Scops is certainly not designed to bolster vets profits as we are basically advising people to buy and use less wormer more effectively so we don't see ill animals and wormer resistance. If we wanted to make more money we'd advise lots of frequent worming to sell wormers!
As a sheep farmer myself, I try to follow scops guidelines more for my own benefit than for the national flock - if I get resistant worms, I will have to buy wormers from a different (and more likely more expensive) class, so it's in my own interest to try to avoid resistance on my own land.

[landroverroy]

The system works

......until it doesn't.  That's what the new fangled guidance is all about - trying to keep our currently available wormers working for us all for as long as possible.



Always using the same wormer, and moving wormed sheep straight onto new grass is bound to result in higher levels of wormer resistance and faster. Since we only have so many tools available, surely that's something we should all be working hard to prevent?

Womble -I don't always use the same wormer!
My system works for me. I see no evidence of resistance and even IF I had built up some highly resistant worms, there are 2 things to ponder:
   1. It affects no one but myself and my animals as they are all sold for slaughter. So I'm not exactly contributing to  the national problem of potentially  increasing worm resistance.
   2. IF  my land is infected with resistant worms due to my "dubious" worming policy, then I must have developed sheep which are resistant to these super worms as both ewes and lambs are in excellent condition.   So maybe I have inadvertently developed sheep with the advanced immunity that Tim W is talking about.

Science is forever evolving. We are not yet (and may never be) at a stage where we know everything about everything. There is frequently more than one way to reach a desired result. It may not be your way, or even the way of the majority, but that doesn't automatically mean it's wrong.

AND I'm not saying - this is what anyone else should do! I answered a question by Dartmoor Liz about what other people do - and now you know!

[pharnorth]

To identify anthelmintic resistance you need to do a FEC after you have drenched to see if the drug has worked---


Yes, of course.

[waterbuffalofarmer]

I worm mine every 3-3 1/2 months and they are very good on that.

[Womble]

Womble -I don't always use the same wormer!

I'm sorry, I didn't mean to infer that you did, just that it's a bad idea.

To identify anthelmintic resistance you need to do a FEC after you have drenched to see if the drug has worked---

I suggested this to my vet, but instead they wanted to do an FEC before worming to check it was necessary, but then weren't interested in seeing another sample to check for efficacy  . Perhaps there are only so many jars of poo a vet can stand in any one week! 

We select and breed for worm resistance......


.....We know all the above because we measure and record everything

So what's your FEC regime then Tim?  Do you take samples from individual animals before and after drenching for instance?