SCOPS Podcast

Practical Options for Performing Wormer Treatment Checks and Faecal Egg Counts

Episode Notes

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Today on the podcast we’re talking about practical options for performing wormer treatment checks and faecal egg counts. What are the major monitoring tools that are available? When and how often should you be performing wormer treatments in the first place? What’s the difference between a good and a bad faecal egg count sample? And, what does resistance really mean? These are just some of the questions that we’ll be tackling. 

Host: Ben Eagle

Co-host: Lesley Stubbings

Guests: Rebecca Mearns (Senior Veterinary Advisor at Biobest) and Anna Hawke (farming near Salisbury).

Episode Transcription

 You are listening to the SCOPS Podcast.


Hello and welcome to episode two of this first series of SCOPS Podcast. The show in which we put the spotlight on sustainable parasite control in sheep. I'm your host, Ben Eagle. I'm a rural affairs journalist and podcaster, and my co host today is Lesley Stubbings, who will be well known to many of you, and was central in the formation of the Scops Group.


Lesley has been an independent sheep consultant since 1997. She's a life member of the Sheep Veterinary Society and works with a wide range of clients, from farmers to the NSA and DEFRA, among others. Lesley, how are you doing? Well, good. Thank you, Ben. I'm really looking forward to this this morning. We've got two people on this podcast who are really, you know, engaged and using faecal egg counts.


And it's always quite a difficult thing to get people to understand how useful it can be. And from Scott's point of view, it's an absolute key stone wormers and anthelmintics really. So I'm really looking forward to this. Yeah. Well, I'm, I'm really looking forward to you co hosting this with me as well. So we're talking about.


Practical options for performing wormer treatment checks and faecal egg counts. Let's start with the main question of what a faecal egg count actually is. Um, what are we looking for and measuring? Why is it so important and how's the information used as well? Okay, that's quite a big topic, Ben. But I think if I can just pick up on how often should we be worming sheep.


And that's, I think, is one of the critical things for sheep farmers is that historically they were told that they wormed them on a regular basis, you know, every so often. And this is where the faecal egg counting really comes in, because What we're trying to do is only worm when it's necessary and only worm those sheep that need to be wormed.


So, so really the underlying thing that faecal egg counting is one of our key tools, okay. And it's a key tool to get into the point that you're only going to worm animals when you need to. And then you make sure that when you've wormed them. It's worked as effectively as you want it to. In terms of what a faecal egg count actually is, what we're trying to do is to get an idea, an estimate, of how many worms are inside those animals at that point in time.


So, the eggs that are in the dung, we're taking dung samples, and I know Rebecca's going to talk about what's a good sample, what's a poor sample, but we want to have a measure of those eggs because those eggs are a direct measure of how many worms are inside the adult egg lane. worms there are inside the animal.


And that again is going to help us point towards whether or not those animals actually need a treatment and how much contamination is going out onto the pasture. So, you know, those two things are really important in terms of time. Brilliant. That was a, that was a very good introduction. Let's, let's welcome our guests.


Uh, we're joined first of all, uh, by Rebecca Mearns, who is a senior veterinary advisor at Biobest. She's an RCVS advanced practitioner in sheep health and production and former president of the Sheep Veterinary Society. We're also joined by Anna Hawke, who farms near Salisbury in Wiltshire. Anna, could you just introduce your flock and your farm and give us an idea of your business?


I farm with my husband Rob. Uh, we are first generation farmers, though we are not technically farmers and more Grier. We have a thousand Romney and Romney cross Highlander use, and we predominantly farm in three locations, all in very different. topography. We do actually for our SINs and to increase our workload even more, manage another 600 ewes for one of our landlords as well.


Rebecca, let's go straight over to you. In your experience, how have things changed in the last five years? Let's look at that sort of bigger picture, uh, the context of where we are at the moment. How many more people are doing faecal egg counts, uh, now, um, compared to five years ago. Yeah, thanks Ben. I think there are more farmers doing faecal egg counts now compared with five years ago.


It's quite hard to put a number or a percentage on how many more are doing it because people will be accessing their faecal egg counts through various different places, so they might Send their faecal egg counts away to a lab. They might take them to their local vet or their local merchant. And some sheep farmers are doing their own faecal egg counts.


So very hard to put a figure on how many more are doing it. But certainly from our perspective at Biobest, we've seen an increase in samples coming in over the last five years. And we still need to get the message out there that faecal egg counts are a really useful tool for internal parasite control.


We know that with initiatives like the Animal Health and Welfare Pathway Vet Review visits in England, and the Scottish Government preparing for sustainable farming incentives, there is the potential for more farmers to get on board, either for the first time doing faecal egg counts, or for farmers that are already doing faecal egg counts to do even more faecal egg counts in their flock.


As we go along, and not just in the last five years, but over the whole time that SCOPS has been in existence, which is a lot more than five years, I think there has become a greater appreciation of testing, not only to see if a treatment's needed, but also to check if a treatment has worked. Because it's obvious to everyone that knowing if a treatment has been effective or not is really key to land performance.


Absolutely. But in terms of barriers, reasons why people might not be doing it, why isn't everyone doing it at the moment? Yeah, it's a good question. And I guess the bottom line is it's not very glamorous picking up sheep poo, but it is an easy sample to collect compared to, for example, blood samples where you're going to need to get your vet out to take those samples.


But yeah, persuading farmers to collect samples is definitely a barrier. We need to get the message across that. It can be done as part of your daily checks as you go around the sheep. Having a stash of small plastic bags in your pocket, so you can pick up fresh samples as you go around the sheep, means you don't need to be gathering batches of lambs to get samples.


There's loads of good resources out there, including on the SCOPS website, including videos that show. How to collect samples. So in people's heads, it's a question of oh, we're going to have to gather the sheep. We're going to have to get the samples. It's a hassle. It's another job to do. But if farmers can integrate it into their daily checks around the sheep, that gets around that barrier, which I think is a significant one for a lot of farmers.


The other barrier, I think, is making sure that at the other end you get really good advice and interpretation of your results. So just providing a count is not really sufficient. What you need is the count in context so that farmers can take the right action. And sometimes that might be, well, let's not treat.


Let's get another faecal egg count in two or three weeks to continue monitoring. And although it might sound unlikely, some farmers really get the faecal egg counting book and they're doing serial egg counts across different mobs of lambs throughout the grazing season, which is great. Thank you. But in general, for most flocks.


It would be a benefit if they did more monitoring for worm control. You know, I just wonder if we could bring Anna in there, actually, because I happen to know that Anna has been out doing some poo samples this morning. And I just think, you know, on that point, in terms of, you know, the hassle factor, Anna, and how you fit it in, um, it'd be really interesting to get your take on that now.


Well, it's extremely easy to take the samples, as Rebecca says. is just having the mindset of accepting that you're going to do it and getting on and doing it. It's added maybe five or ten minutes extra to my daily check this morning, but that's it. The benefit of the information that I can glean from this is going to be very important.


As I go on,


just following on back to Rebecca, just for a second. So you're obviously you're getting samples sent into the lab, Rebecca. What have, what can you just explain to people how that works? You know, what materials people use and then what happens in the lab and then Anna's doing her own and we'll come to that in a minute because she's doing her own farm.


Yeah, that's right, Leslie. So we'll get sample sensors through the post. So from that point of view, there's obviously a delay between the samples being collected. and is getting them at the lab for processing. And it is really important when you're collecting samples that they're as fresh as possible straight from the sheep, but also that they get to the lab in a decent time frame as well.


So taking them in plastic bags is quite good because you can roll them up to squeeze out excess air before you seal the bag, if you've got those little grip seal type bags. So they're really good. And if there's going to be any delay in posting the samples, Pop them in the fridge and you can do that overnight quite safely to get them in the post the next day.


But you do want to get them to the lab as soon as possible, because if they're held at room temperature for any time, that can mean that the eggs that we're counting in the lab are not the same number as were there when you actually took the sample, because some of them might hatch in transit. So when we get them at the lab, we get a mixture of different types of samples in.


Sometimes we get samples that have already been pooled on farm. And in that case, we would be expecting that a similar amount of dung from each individual lamb has been popped into one larger bag to create the pool. And we'd be talking about a heap teaspoon equivalent from each lamb to contribute to a pooled sample.


Or, what we also get is individual samples which we then will pool at the lab. So in that case, again, a heap teaspoon equivalent from each lamb. Send off your samples. We like 15 samples, ideally, to make a pool. And at the lab, what happens then is the samples are individually weighed, and then they're all mixed really thoroughly together, having been weighed so an equivalent amount is from each sample.


Really thorough mixing, which is a very key part of the process, particularly whether you're doing that. at your own farms. If you're doing it in your vet practice or if you're sending to a commercial lab, mixing is a really key part. So the sample that you're taking out is a representative of the larger pool and then that sample is processed to get to the stage where you're floating the eggs in a saturated salt solution and can look down the microscope and you can count the different number of eggs.


Um, some of the eggs look quite similar. So you'll get a count which we normally call the strongyle or trichostrongyle type count. And this includes the most important and pathogenic worm species of sheep. And then there may be a count of other eggs, which you can count separately because they look differently.


So for example, nematodirus is, is a good example of that. And then what you will get is a number of eggs per gram, which is the count. For, for the worm eggs. And that's what will be reported back to either the vet or the farmer and which you can then interpret in terms of how your lambs are performing, how high the count is, and what action you might or might not take.


Thanks Rebecca, that's brilliant. So, Anna, how does your system differ? Because, you know, you're doing the, uh, the Techeon system, you've got what we call a FETPAC on farm. How does your system differ from using the lab? My system doesn't differ very much. I am, collecting a pool sample. And I have a measuring spoon, which I use to collect mine.


And as Rebecca says, it's then a question of amalgamating, really mixing all of those up together with the system that I use. I then prepare it, and then it goes into a slide, a digital microscope, then reads it, and somebody else actually interprets those eggs that are there for me, so I don't actually have to count them, but that gets sent off over the internet.


And then the results get sent back to me within an hour, I could then take a sample, prepare it and have the results back. Not everybody needs that time scale. And there are certain times when I don't, but there are certain times when I do as well. It just is easier for me with this system that I then don't have to take it to a vet or to a merchant.


And then, then have to prepare it. It's all done as it were in house with me. So that is the system that I use, but everybody has different systems and it's what suits you best. I think that's the point, isn't it? That, you know, there are different ways of having them done that suit you and, and you know, you doing your own and that speed to even get.


quicker in time in terms of almost Pennside making the decision, but for other people using a lab, they don't want to get involved in all of that. There are different, yeah, horses for courses, I guess, Ben, really, in that sense, you know, there's something for everybody. One of the things I was just going to ask both of you really was what makes a good sample and what makes a bad sample?


Is a bad So, yes, the samples that we get in


are good, and if you have bad samples, which might be old samples, not enough samples, not enough animals sampled, that can really affect whether or not the result that you're getting is meaningful, and is, you know, robust enough for you to use in your worm control. So, I guess there's three main caveats for, for quality of samples.


One would be enough samples, and that's both enough poo from each individual, but also enough lambs sampled from the mob. And I would say 15, certainly no less than 10, and the science and the guidance from the World Association for the Advancement of Veterinary Parasitology. Fresh samples, so ones that are literally warm in your hand, in your gloved hand when you pick them up, not those crusty dry ones that have been there overnight.


And also random is really important from the batch of lambs so that you're not saying oh, well, you know, these lambs look a bit poor I'll select those. What you want to do is select random lambs So the way Anna does it where they're in a corner and then they move off obviously She doesn't know which lambs have passed which pile have done at that stage And if you're running them through your handling system, you may just say well we're just going to do the first 15 and we're not going to pick out the poorer ones or the ones with dirty tails because Obviously, lambs might have dirty tails for other reasons, and it is important, if you're not going to sample the same lambs, for example, before and after treatment, where you're trying to see if the treatment's been effective, you do need to make sure that it's random.


Thanks Rebecca. So, are people doing it enough? I mean, how many, how many samples do you think people should be taking? And then Anna, maybe you can say how many, how many samples you actually take. Are they doing enough? I think the answer is probably we could always all be doing more. I think people tend to start a little bit later perhaps in a lot of flocks, so maybe we should be starting certainly well before weaning and from around the time when the lambs are eating enough grass and grazing enough grass.


So starting from around. Six weeks of age might be a good guide for many flocks and following it through doing serial samples across the grazing season is really important. A single one off fecal egg count is not really a powerful tool in terms of worm control. You need to be doing serial sampling. So coming back to Anna then, how often would you do it?


And I mean, I mean, we're sat here now recording this in October and I think Rebecca, you would be saying people should be carrying on now. They give up. Let's carry on. But how often would you be looking at sampling Anna? We generally start cycling at about eight weeks of age, and we continue, as I say, we've started at eight weeks of age, and we will continue.


We've seen that the season is going on much longer. And, uh, certainly a few years ago in January, I know that, um, we'd got some lambs that weren't performing very well and we did effect sample on them and the egg count was through the roof. So certainly with the milder weather that we've been having over recent years, the season for the worm burden has got much longer.


I think that as long as you've got lambs that you're trying to fatten, you should be sampling them. And Anna, just on the subject, I suppose of encouraging, um, encouraging more people to be doing more from a farmer perspective, from your perspective, what do you think we could do to incentivize more people to take more samples?


That comes back to an individual approach. A, a good question to ask somebody is, do you think that you would be able to farm your sheep without worms? Um, because if you have no worms that are working effectively, then you have no tools to be able to farm in a very resilient and. profitable way. It's something that comes from within and having that knowledge will help you to make the best that you can from your business.


So Lesley, as part of DEFRA's new animal health and welfare pathway in England, Scops has helped to develop the Worming Treatment Check. Can you just give us an idea of what this is and how it works? Yeah, thanks, Ben. So yes, we've developed this and it's deliberately called a worming treatment check because, um, it isn't a direct measure of whether there's resistance, but it's telling people something about whether or not the worming treatment that they have given has worked effectively.


Now, there are two sides to that is that one is to encourage them to actually carry this test out properly and make sure that they've treated the animals properly. And if they do all of that, The right dose rate and they check the calibration of their guns and everything, then they will be able to go on and use it as an indication that there may be some resistance there that they can follow up.


So it's a bit of a, a two pronged approach, if you like, and we've developed this, um, using laboratories rather than. using, people using their own, which is no, no, um, Castagnanius versions of what Anna does or anything else. But we know that it's really important that we have some sort of checks on the quality of the sample, as we've heard from both Rebecca and Anna earlier in the podcast.


So, you know, this, um, gives people a kit. It gives them some really detailed, um, instructions onto what samples to take and when they do a faecal egg count. before they treat the animals. And then they only treat them if they need to. So we know how many worms were in the animals at the time of treatment.


That's really important. And then they treat them with their wormer. And then we go back and take a second sample either at seven or 14 days post treatment, depending on the product that they've used. And we do a second faecal egg count. And what that does is it gives us a direct measure, how many of those adult worms that we were talking about earlier have been killed by the treatment.


And, and as we've said, you know, there are other reasons why there might not be a total kill. It might be that they've used the wrong dose rate. Um, in which case, you know, there should be discussion with them and their vet. But if they follow the instructions properly, it will be giving them a really good first indication as to whether or not that particular wormer group is working effectively for them.


Just turning this conversation towards resistance, I suppose, and we'll talk a bit about what resistance really means, but how effective is this as an early indicator of that? I mean, it's effective as an early indicator, providing people have done it properly. And that's really why Rebecca and I particularly have spent a lot of time, um, a lot of blood, sweat and tears on this in the last 12 months to make sure that when people do it, they get some information, which is useful and is teeing them up to say, Hey, hang on a minute, you know, I thought that was working properly for me, but we use a cutoff of 90%.


So let's say there were 500 eggs per gram as, as Rebecca was saying to start with. And we treat and we go back and have another look. And there are more than 50 eggs per gram still present in the second sample, then we would be saying, Ooh, cool. This, this, this could mean, you know, you're not getting an effective kill.


Your lambs probably aren't performing as well as they might be. You need to be thinking about this, um, and, and talking to your advisors about how you next, next proceed. Um, so, so it is. A really useful indicator and we've worked hard on how that's presented in terms of a heat map and everything to people so they can see on a nice heat map type scale where their results come and really encouraging that discussion within the pathway where the vet is doing the review and there's a conversation going on that they can help the farmer then take the next step.


That leads on quite nicely, actually, to the way that terms are used, isn't it? And when resistance itself is used, when you're looking at an effectiveness of what you're doing. Leslie, let's start with you on that. What does resistance really mean? When we use the term resistance, what are we actually referring to?


It's a great question, but actually because it, it's misunderstanding that at farm level, which can lead people into making knee-jerk reactions and, you know, we'll come to Anna in a minute and talk about her, her situation. But, you know, resistance in the scientific sense means it's the ability of that parasite and we have it in other parasites, obviously other than worms.


The, the ability in that paras act to with withstand the normal dose. Of the medicine that's been given of the antelmintic, in this case, the wormer. So a worm that can survive that is said to be resistant to that particular wormer. It's a genetic ability within the, in that worm. So when that worm survives, its genetics survive.


So it then goes on to breed with other susceptible worms. And that's how the level of resistance builds over time on a farm, because gradually. The genetics within the worm population sways towards the resistant away from the susceptible. So some of the things we're trying to do is to try and, when we have treated, dilute those resistant worms out, for example.


Now, we're not going to talk about that today, but some of the other things that we do are designed to help us to keep those resistant worms under control. So one of the things that, that in a practical level. For many years, for 40 years now, scientists have been talking about, oh, we've got resistance in worms in the UK.


And the problem is that resistance, yes, we can go on most farms now. Um, and with very, very detailed techniques, we could pick up some genes for resistance within that worm population. The problem comes in that. Most farmers, unless they're doing the sorts of tests that we're talking about now, won't notice that they've got resistance until the wheels have come off, until the worm population is pretty solidly resistant.


And then they say, Oh, we've got resistance. Um, but actually that's been building over many years and what we're trying to do now is detect that at an early stage. At this sort of 10 percent resistant level, we can detect it quite well, the early start, the early signs of it. And then we can do all these other things to slow it down.


And that's really what we're after trying to do here. Um, and that's what's really important because the earlier we can get it. the more we can do. The later we leave it, the less we can do. I wonder if we can bring Anna in here now and just ask about, you know, whether you can share with us, Anna, what your road of discovery has been with, um, the resistance status within, within your, well, farms, I think, because they're likely to be different, aren't they?


Yes, Leslie, that's, that's quite the case. They are different within different blocks of land that we actually graze. We have only established this through the use of FEC. It was being suspected for a lot of years, but this is actual proof now that, you know, there are tests that we can do, as Leslie says, to actually find out what are resistance status is.


And we know that we, with a white wormer certainly have, and on a certain block of land, we have a levamosaur resistance. But we've only known exactly where we are within that level, through doing fissure leg counts. That has been invaluable to us, not only from a monetary point of view, but from a time point of view.


I think that as farmers are very easily, um, led down just thinking of a monetary value and not putting their time in. This has huge benefits for us and for the industry as a whole.


So Rebecca, you know, I mean, Anna's talked about different parts of the farm and so on, but how, how are we, you know, how is this going to change? over a season, for example, in terms of if people do one test, is that telling them everything? No, certainly not, Leslie. That's why it's really important to do several faecal egg counts over a grazing season, because most worm infections in sheep will be Lots of different species of worms and some of those species are not very pathogenic They're not doing much harm to your sheep and some of the worm species are So when you get the results of your worming treatment check after treatment You don't actually know which species of worms have survived treatment So might be resistant and which species of worms have been killed and what we don't want is people saying, okay I can't use that class of wormer at all in my flock because the different species of worms that are present will change throughout a grazing season.


So a lot of people might know about the nematodirus forecast in the spring, which is when we tend to see that species, and we talk a lot about that in the springtime. As the season goes through, other species of worms predominate. It's different farm to farm, field to field, but there's general trend in terms of which species are present.


So if you were to do a worming treatment check using, for example, a white wormer, In the height of summer in maybe July and you found that it didn't work The species of worms that are present in the autumn, there may be a different dominant species there and if you tested a white wormer then, it might have a different level of effectiveness.


And that's why it's so important to do, you know, lots of faecal egg counts and not just one, because you're not talking about a snapshot that you can base all of your worm control on. We don't want any knee jerk reactions. It's about building up a picture because the worm species change. and whether they are or are not killed by the different actives will also change.


Let's start to draw this together, I suppose. So, in conclusion, I mean, when it comes to faecal egg cancer and Wormer treatment checks, the big question is, I suppose, what's next? What should listeners be looking out for? Leslie. Um, well, I think over time and certainly in the last five years, you know, the ability of people to access FECA led counts has improved dramatically.


And I expect that that will improve more. We're seeing more technology. I know the system that Anna's using now is looking at machine learning AI to be able to help with the interpretation. You know, we're going to see some more technology coming in there. So I would hope that. It'll get easier and easier for people to access faecal egg counts, I would hope, and I think the Defra pathway will help to, it's an entry point, it will help to open that door.


The one thing that I think, and I know Rebecca's going to smile at this one as well, but the one thing that we're all working towards now is that, as Rebecca's mentioned, the species of worms change over the season. But when we do a fecal egg count, the only differentiation that we can really reliably get at the moment is between nematodirus and, as Rebecca said, the strong isle types.


What we're working on now is a commercially economically viable means whereby. we can speciate those worms, um, into different species because when it comes to resistance, knowing which ones you've got and knowing which ones are the ones that have failed to respond to the treatment as opposed to others is really valuable.


And that's something that we are currently working on now, Rebecca, isn't it? Um, to try and bring that to market if you like. The science is there. We know it can be done, we just have to make it workable at a practical level. These are available as research tools at the moment and I know, you know, you've certainly used them in some of your research and it's been fascinating looking over time at how these have changed the different species and they haven't always complied with what we consider to be the normal expected seasonality of worm species.


They've sometimes thrown a bit of a curveball in there and it's been really interesting and that's highlighted. How valuable having these tools commercially available would be to farmers like Anna in terms of adding a next tier of knowledge that you can use as evidence for your worm control strategy, um, not commercially available yet, but something which I think would be a really powerful tool.


Can we get Anna's thoughts on that? I mean, Anna, would that make a difference for you? Yes, it would certainly make a difference to me. I mean, we have. We have seen over the years that at different times of year, which is just backed this up, the conversation up completely, different wormers work at different times of the year, but without us doing those faecial egg counts.


Then we wouldn't have known that. And I think that a lot of other people will be surprised. You get the bug. You do. And it, because it then becomes second nature for you just to do them. Um, even just randomly, just so that you know where you are, you just build up this picture. I think that is the mic drop moment.


Uh, that's all we have time for today. But, uh, big thanks to our guests, Rebecca Mearns and Anna Hawke, and big thanks also to my co host for this episode, Leslie Stubbings. Thank you very much for listening. Please see the show notes for more information. Uh, in the next episode, we'll be focusing on sheep scab and how to treat it.


Um, in the meantime, you can find lots more information on the SCOPS website, which is SCOPS. I've been your host, Ben Eagle, and you've been listening to the Scops Podcast. I'll look forward to you joining us again next time.