We're going to talk today about keeping the early pregnancy going in the mare. I, I think this is a really important topic for those of us in equine practise or or or mixed practise, regardless really of whether we do large numbers of mares or small numbers. Keeping the early pregnancy going once we've established a a a pregnancy in the mare.
It is really important and when we lose them, it's frustrating for all concerned, so I hope, you'll agree with me that it's worth time, a worthwhile topic to have 50 minutes or an hour or so talking about. Just by way of a little bit of a background, those of you I don't know, I set up equine reproductive Services, a, First opinion and referral, general equine practise, but obviously specialising in reproductive work, almost 25 years ago now, I'm now what they call a consultant in the practise, which really means you don't do an awful lot for it, but it's a grand title to have. And I also work as a claims consultant for the equine side of the Veterinary defence Society.
My colleagues here, some of you may know, particularly you may know Jimmy Crabtree, who I refer to a couple of papers of his. Charlie Cook's also a director of the practise and has published extensively, and the other colleagues are all heavily involved in. Equine reproduction as well as general equine veterinary work, so that's a little bit of a background about me, further information always, there are some excellent textbooks around, Particularly current therapy and equine reproduction with that stellar cast of editors there, all joking aside, there is some good information in it.
I'll refer to some chapters in that book, particularly in this webinar we're doing. So if you can get your hands on a copy, that would be. Good, I think, much of the information, although the book is several years old now, does remain current, and there are several other equine textbooks which you may have come across, which you'll find helpful.
There's the, the, the equine reproduction tone by Angus McKinnon and his colleagues, of which I've written some chapters in that, and there's a very good, which perhaps slightly lesser known atlas of equine ultrasonography, which is a very good general equine veterinary book. And there's some good chapters on equine reproduction. There's both the normal mare and I did a chapter on equine reproductive problems detected using ultrasonography.
So, that's a little bit about where you can get some background information. It, it's, it's, we've kind of got used to doing these virtual congresses now. There's some good points, of course, because they, they potentially at least allow a wider audience, and you can pre-record them and watch them at your leisure and so on and so forth.
They they're slightly more, or I find them slightly more difficult as a speaker, presenter, because I, I, I love to interact with the audience, those of you who've been to any of my talks know, I, I, I like to ask you questions regularly throughout it, mainly to make sure you're staying awake. That's a little bit harder, but I'll I'll try and put some questions in, so here we've got one look. What statement is false?
Early pregnancy rates have increased in the last 20 years. Less mayors lose the early pregnancy now compared with 20 years ago. Live foal rates have increased in the last 20 years, or the same number of mayors lose the early pregnancy now compared with 20 years ago.
Now, 3 of those statements are actually true, only 1 of them is false, and. The first one really is that less mares lose the early pregnancy now compared with 20 years ago. Now.
There may be very marginally less mares do it, but the, the point which I'm trying to make with this slide is that unlike many of the other aspects of equine reproduction, at which we're doing considerably better than we were in terms of pregnancy rates over the last 20 years, we're getting more mares in foal with chilled semen, more mares in foal with frozen semen, we're better at dealing with problem mares, and so on and so forth. But we're really not doing. Much about reducing the impact of early pregnancy failure and, In our practise, we've developed some protocols which are, I'm gonna put up there for discussion.
I'm not saying they're what you have to do in your practise, or what you may have heard other reproductive specialists talk about, but they have worked for us. I can absolutely assure you we're in the coalface of equine reproductive practise, so I can assure you they've worked for us, and I'm gonna share them with you and. You can have a think about them and I'll leave you to make your own judgement up about them, but I hope you'll find them useful and straightforward to apply in your practise should you choose to do so.
So it is an important topic, it's a major source of economic loss to the horse breeding industry, so it's worth talking about. Let's as a start point, say, well, I, I, what's the fertilisation rate in the normal man? Well, it's high.
I, I, I'm always wary we put figures on things when someone says, oh well, it's actually 92 or it's 94 or it's 89 or whatever. I mean, let's, it, it's high is a good way of putting it. In a percentage term, let's go for it certainly more than 90%.
So the fertilisation rate, the normal mare, more than 90%. Of course, various things can impact on that, particularly with regards to fertilisation rate, we think it's older mares, and we think the most likely cause of the problem in older mares with fertilisation rate being lower is they may well have oocy problems. Of course, in reality, as you may imagine, we don't know the true incidents before day 6 because it's very difficult to.
Access, we can't diagnose pregnancy at that stage, obviously, the early pregnancy is in the. Oviduct, it's not descended into the uterus, so it does become difficult to know the real incidence before day 6, which is the time at which the early pregnancy descends into the uterus. Now, having said I don't like putting percentage figures on things, we have to, if we're gonna work in this industry, we have to understand what our percentage figures, but we must always bear in mind there's a wide range and an enormous natural variation.
So against that caveat. Between days 14 and 6 and 36, estimates vary, as you would expect, 8% through to 20%. Now, I'm not gonna get into to to why there's that huge variation.
Suffice to say, if you had to tell me what's the biggest thing, well, it's extremely age dependent. The older the mayor, the more likely you're gonna have an increased percentage of, of, of, of losing the early pregnancy. So you're going to move yourself up towards the 20%.
A younger, healthy mare, 789 years old, you're gonna move yourself down towards the 8%. And for more information on that, there's an excellent chapter in current therapy and equine reproduction, written by Dirk Van der Waal and Johnny Newcombe, going into this subject in a lot more detail than we can do here. So I'd refer you to that chapter if you want to know a little bit more about it.
Now, on a practical level, I always like to give you, rather than just regurgitate what you can read in books. When we're actually giving the presentation, I like to go through some of the practical things over the years which have happened. And what you'll often find, or certainly it did for me, so I imagine it will for you, when I'm scanning a mare for the first time at 1415 days after ovulation, and oh yes, I can see a early conceptus there, this mare is in foal, this mare is pregnant.
Many mare owners will ask, well, doesn't that mean, John, that in. 11 months, 4 days or whatever we work on from the time she was covered, being the gestation period. Oh, my mare's gonna have a nice healthy foal and obviously the more knowledgeable mare owners won't be in that position, but perhaps newer people to breeding may not fully understand why their mare scan in foal at 14 days will go on to lose that pregnancy rather than produce a live foal.
And, Perhaps we get, we've got a little bit, I don't know whether immune is a word or blase, to the fact that scanning a mare at 14 days for pregnancy is very early. Not many other domestic animals, have pregnancy determined, or or veterinarians have the ability to determine pregnancy as early as 14 days. Now one of the other challenges which I think we face with early pregnancy failure, is that the causes are multifactorial.
There are many causes of early pregnancy failure, and whenever you've got a condition which has many causes, it becomes a difficult concept to do much about in terms of coming up with an effective management stroke therapeutic approach to reducing the incidence. So, we've got to understand at the outset, it has multifactorial causes. One of those textbooks which I mentioned at the outset has this as a paragraph or a sentence.
Our belief is that persistent, unidentified, or poorly treated acute and chronic inflammatory conditions of the uterus are responsible for the majority of problems of early pregnancy failure. That's, that's quite a bold statement. So you've got to ask yourself, what do we think of that statement?
Do we agree with it, partially agree with it? Definitely agree with it, don't have a view on it or disagree with it? Well, I, I, I have to come clean.
I, I have to agree with the statement because I wrote it along with my good buddy Angus McKinnon, you can see this was a, A little bit, it's hard to come across in a, in a, a virtual lecture, but I'm just showing her that little slide there, that, that's, that's Angus in the front there, that's my other good friend, or well, I've got more than 3, but, or more than 2, but that's Doctor Wan Sampa, who you may know, we, we've done a lot of lectures together all over the world and I think they always treated me as a sort of young. Younger one of the group, which, which I was, but, anyway, enough of that, I, I, I don't want to ramble too much. I just wanted to make the point, Angus and myself said this, Sentence, I was doing a a a webinar with Angus a few months back and I checked he was still happy with this comment, and it remains, that is our belief.
What are we saying in that? Well, we're saying we've got to get the uterus right after breeding, to be able to support the early pregnancy, and this leads into what we all know is a problem after breeding in mas because there's a, a, a, A risk that a a mare will get a persistent post-breeding endometritis, uterine inflammation and how you manage that uterus of the mare, post-breeding is vital, not only in terms of achieving a pregnancy, but in terms of reducing the incidence of early pregnancy failure. These are the kind of mares, I mean, these mares we know, it's not rocket science to to know, these mares are going to be more prone to persistent breeding induced endometritis, and they are gonna be more prone to losing the early pregnancy.
So we're gonna have to work really hard on the uterine uterine environment of that mare, post-breeding to ensure not only a pregnancy, but that that pregnancy will be maintained. OK, having nailed my colours to the mast, or, or that's an expression, meaning that's what I think's really important, that, that aside, it is a multifactorial problem. So, it might be helpful if we break the categories into genetic categories, of which you can have defects arising at fertilisation, maybe chromosome abnormalities, maybe age docytes.
Environmental, problems in the uterus. Foal heat breeding, endometriosis, endometrial cysts, or persistent fluid, persistent fluid being, if you can notice, in a slightly increased font to try and highlight the importance of that. And then the other group of problems which may cause early pregnancy failure could be endocrine problems.
Now, the endocrinology of pregnancy in the mare is, is, is complex, and we, we can't get into that and the various hormones and feedback mechanisms, today. So let's just suffice to say it's, it's complex, the, the early pregnancy hormone situation. One hormone I do want to talk about because using progesterone or synthetic progestogens is common in an attempt to reduce early pregnancy failure.
It's, it's a to a degree controversial. We used a considerable amount of progesterone in an attempt to reduce early pregnancy failure and. Not everyone necessarily thinks that's useful, but, we did, and I'll try and explain the background to both how we use progesterone and why we think it helps.
As a definition, I mean, most of us, I think would work with early pregnancy failure being pregnancy failure, pregnancy loss, that occurs up to day 40. As with percentages, putting a a a a number to the days is is a little bit artificial, but I think most of us are, are quite content to accept that as being early pregnancy failure. Pregnancy loss occurring up to day 40 of gestation.
And again, I refer you back to the chapter in current therapy and equine reproduction, . Where that that concept is elaborated on and the percentages and possible causes, elaborated on also. I just wanted to flag up, two reasons I like flagging this up to you.
First, it's always good to present new work that's out there or to draw your attention to it. And this is an excellent paper only come out. I, I don't, the last few months, whole genome analysis reveals annuloid is in early pregnancy loss in the horse, .
I also want to draw your attention to it because it's wonderful to see my compadre and Equine Reproductive Services, Jimmy Crabtree, contributing to such a a, a major scientific publication and highlighting that even when you're in equine practise, it's still important, I think, to make a contribution to the literature and scientific body of work that's out there. So this is an excellent paper, I'd refer you to it. I've just picked out a couple of bullet points which, I, I, I wanted to do, and they say, they're saying in it equine early pregnancy failure, EPF being early pregnancy failure, has no diagnosis in over 80% of cases.
Wow, so that's really saying a lot of the time we don't know what's causing this early pregnancy failure. And without putting a percentage figure on it, anyloidy, which, just to give you a definition of it, gain or loss of a whole chromosome, is involved in equine early pregnancy failure, and this scientific report is, is certainly one of the first papers to refer to it in equine early pregnancy failure. So, I'd encourage you to have a, to have a read of that for a little bit of up to date information on it.
Let's, let's talk about what we can detect, in terms of early pregnancy failure first and then we'll move on to how we may manage it. If we can't detect it, then it's it's, it's difficult for us to manage it. We can detect it with ultrasound because we may see a small for age pregnancy now.
That is correct, but what you have to remember is that a pregnancy, and by pregnancy I'm meaning here, we've got a conceptus here, this is, this is a twin pregnancy, of course. This is one conceptus and this is the second conceptus. Using the scale along the side, this conceptor would be around about 18 to 20 millimetres.
This one's gonna come in at around about 15 millimetres. Now, OK, that, the one on the right, as I'm looking at it, so this one, if there's some kind of reversing screen, that is clearly smaller than that one. But it doesn't necessarily mean.
It's small for age, because we would need to know if the ovulations that resulted in this twin pregnancy were synchronous, did they occur within 12 to 24 hours of each other, or were they asynchronous, more than 24 hours apart? And if they were asynchronous, then this. Little smaller pregnancy there could simply be arising from an ovulation 24 hours, 3, 36 hours after the ovulation that led to that first pregnancy.
So whilst small for age may be an indicator of early pregnancy failure, it may just be that The smaller pregnancy arose from an ovulation which occurred some hours subsequent to the first ovulation, so you, you need to bear that in mind. An embryo failing to appear. As I said, some people loosely term this the embryo, well, it, it isn't.
That is an early pregnancy, we could call it a conceptus. The black fluid, the anechoic fluid there is actually yolk sac fluid. The embryo itself has not appeared.
That is the embryo itself, this 3 to 4 millimetre, ecogenic whitish greyish structure appearing generally in this, 567 o'clock position within the trophoblast within the entire pregnancy. Here you can see this dorsal thickening of the uterine wall, which lets you orientate this image, so we know this is dorsal aspect of the uterus, so we know if this were a clock face, we can see that embryo appearing in the 567, a clock position. Now, We, we noted pregnancies over many years where the embryo failed to appear.
And when we first began to record this and note it, well, we would follow these pregnancies, possibly up to 30 days, 35 days and beyond, waiting for the embryo to appear. As we investigated this study, it looked at outcomes over the years. What we've decided in our practise is that any, Conceptus, where that embryo fails to appear by day 25 from a detected ovulation.
Now, I'm saying there day 25, you have to have been quite accurate with your follicle evaluation here, so you're able to know when that pregnancy is at day 25. But in our practise now, if there is no embryo visible by day 25, we're pretty comfortable that that pregnancy's ultimately gonna fail, even if the embryo does go on to appear. So, you know, we'll actually think very long and hard about giving those mares a prostaglandin injection, recycling them round, and, and, and, and, and starting again.
What is this an ultrasound image of? It's a mare which is 14 days from a detected ovulation. Have a little look at that, see what you can see.
I've got a video clip, not actually this may, but of a, of a, of a 14 day scan with a similar situation going on, which hopefully it'll play. I, I never edit the videos which I do, so this is just me scanning them there in real time, . I'm going to, not spend too long on it.
I've whipped up on the left ovary. I just know that because I always do the left ovary first, big follicle, in, in the left, a little bit of fluid was there. And then, oh, I've come down to the base of, probably the base of the left horn, I think.
There's a, a 15 day pregnancy, almost floating around in a, in, in a sea for want of a better word, of inflammatory fluid. Quite a spectacular picture that is, I always feel. Amazing how that 15 day pregnancy has developed.
You know, it's only 15 days from ovulation, so there's been no growth retardation up to this stage, but, you know, over the years we've followed these mares. If we go back to this mare in a couple of days, then that pregnancy will have gone. But amazing how it develops up until 15 days, .
To all intents and purposes from our looking at it with an ultrasound normally. So this is a a a 15 day conceptustrophoblast, yosak fluid, surrounded by ecogenic, almost certainly inflammatory fluid. What what are we gonna do with this, man?
Well. I'd pose these 3 questions. Treat with antibiotics and I'lltranaest, give prostaglandin, do nothing.
I think there's such a large amount of fluid in that may really, the game's over, as it were, that pregnancy is going to fail. I think most of us would agree about that if I posed that as a question to you, . So, I mean you could give it prostaglandin start again in reality, you probably don't need to.
I mean, we would probably say, right, I'll check this mare again in 2 days and see what's going on. And when we came back in 2 days, probably that pregnancy would have disappeared, but there'd be the residual fluid and inflammation going on in the uterus. So we would have to set about, you know, lavaging, oxytocin.
That may to, to, to clean up her uterine environment. Now, here we've got a a a similar case. This is another early pregnancy scan, 1516 days.
There we can see the conceptors, and there we can see a much smaller amount of fluid, isn't there? So there's fluid there, but a much smaller amount. Take a look at that.
Now, we're in with a bit more of a chance here I think to do something about that. Whoa, let's do something. I, I, I'm always very .
Active and aggressive at trying to treat problems in mayors. I'm not, not just a poor, well, let's, let's let's wait and see what happens. No, we've got a, we've got an amount of fluid there that let's try and get on top of that, so.
We, we think that's likely to be an inflammatory, and infectious situation, so we do give antibiotics to those mares, as well as a progestogen supplementation, in an attempt to reduce any inflammation by treating any, you know, presumably there's some residual, . Infection in that uterus. So we would probably use perhaps initially a pen and gentamicin given by injection and then go on to an oral trimodiazine.
And because I think we're at risk for early prostaglandin release and therefore lysing, destroying the early corpus luteum, we would put that mare on a progestogen supplementation as well. So that's when there's some fluid, but not as much as in the first example we talked about. What about if we kind of go one back, one step even further back, we have no free fluid in that uterus, but we've got a widespread edoema pan.
Now, what do we know about edoema when we scan a mere for 15 days? Well, in, in my opinion, a degree of you trying edoema. Let's take this one up here, around the early conceptors, but pretty localised.
I, I'm not concerned about that particularly. I think that's, that's, that's essentially normal. We see it so many times.
What I don't like to see is that, endometrial uterine edoema pattern spreading well beyond the actual conceptus, at the base of the left or the base of the right horn. If we have a conceptus at the base of the right horn. And we scanned up the left horn and there's a degree of edoema pattern obvious.
I, I don't like to see that. I, I'm, I'm, I'm nervous, I'm worried that there isn't as much progesterone around to help look after that early pregnancy, as there should be. And in this example, with this uterine body, there's, there's really quite a marked edoema pattern.
And again, that's something I would be not wanting to see in my first pregnancy scan. Now, what I, what I, as we know in life, we don't always get what I want, or what you want. So what do we do if we see that widespread edoema pan?
Well, again, I think you're gonna have to put consideration to, first of all, going on the ovaries and checking out the corpus luteum and if you can see an obvious corpus luteum. Well, OK, fair enough, you may think there's going to be enough progesterone around, but in many cases where you have this widespread edoema pattern, that's in conjunction with the corpus luteum not being very obvious on scan. And in those measures, we will begin a progestogen supplementation programme with.
Now, I'm gonna come back to progesterone in the final 10 minutes or so. We're we're about halfway through where we're going, so I hope you're all, you can, you can maybe pause it if you want, get yourself a coffee or tea. We'll press on, so I'll have to just have a quick drink of tea.
What, what, what I want to do now is, is move into, as if I perhaps hadn't got controversial enough with the first half. Let's talk about Boocerein, GNRH GNRH agonist. The, the, the drug we did, or used to or or product we used, in our early trials of, of Berrellin for prevention of early pregnancy failure was recepttal.
At that time it was made by Intervet, there's all kind of lots of takeovers and that now, so that, that, that's a picture of that drug from the time we were doing our trials. Now, we were, we were asked, myself and, and, and, and a colleague also doing large numbers of, of, of mere pregnancy scannings were asked, look, we've got this drug, recept our product that is getting used in the in the cattle industry, and, and there's a belief that it results in a 10% improvement in pregnancy rate. Now, the, the mechanism, and, and they showed us the papers in cattle, we read some of them, I'm not professing many of you out there know an awful lot more about bovine pregnancy than I do, but my my understanding of reading the papers they gave me was that the mechanism is, and I think it remains unknown.
I mean, one has to imagine it's either somehow the receptile inhibits luteolysis, or it stimulates luteal function and. The jury seems a bit out on which it is, and it, it could indeed be a combination of them. Anyway, let's let's park that idea.
That was really just the stimulus for the folks from the, the, the drug company asking us if we would conduct some trial work to see if it could improve pregnancy rates in mas. So I'd done enough background reading to think, well, I don't think this is going to be detrimental, So I, I, I think we're justified in going ahead and doing the field study to see what effect, if any, it had. And you can read the paper, I'm not going to spend a lot of time about it now, theory of genealogy, oh gosh, doesn't that that dates me now, 1996, .
The effect of GNRH analogue, booster rate I'm missing Dyson preserates and ferrine mas, no, I'm not gonna go through all the work here. I'm gonna pull out for you the, the bullet points or the. You know, main features of that study, but those of you who are interested or thinking about using it in practise, I, I'll give you another couple of references, in the subsequent slides, and you can actually read the original papers about the studies we did.
And what we found was it did increase pregnancy rates after breeding at the first estrus. Now, only a few percentage points, we're not talking about a a a a a an enormous change here or an enormous increase, but there was a definite increase in pregnancy rates after breeding. And it also increased the maintenance of pregnancy rates, not, not just between those two days, obviously day 28 and 30.
What I, what I'm really trying to say that looking at mas scan the first time at, at 1415 days, second time at 2830 as we did then. We do a little bit earlier now, but then we were doing at day 28:30, . Less mares had lost the pregnancy from 1st to 2nd, scams.
And this is, I, I, I wanna try and, I, I better spend some time just trying to explain what I mean here. The increase, let's read it first, the increase in pregnancy rates at the 2nd and 3rd cycles were greater in treated versus non-treated mares compared with the 1st cycle increases. So what I'm saying here is, when I, I, when we did this in May's getting covered, bred, inseminated for the first time, so they're on their first cycle.
We saw less of an improvement by using receptile to try and increase pregnancy rate and prevent pregnancy loss rate. Then we did when we use it at 2nd and 3rd cycles. Now why might that be?
Well, In common, I, I, I guess a lot of, a lot of colleagues would have as a typical per cycle pregnancy rate, something of the order of 65%. Dealing with a lot of younger mares, maybe we can push push that up to 70%. But around about 65% per cycle pregnancy rate.
Now, the 35% then of mayors which don't become in foal, well, they have some sort of problem. So by the time you look at 2nd and 3rd cycles, you've begun to deal with problem mayors. And what, what you find with that is.
That's, that's the explanation of why I think we see a bigger increase in percentage at the 2nd and 3rd cycles. Now, other workers have looked at, not really, there hasn't been much work other than the work myself and others have done with ReceptA. There was a paper came out of Germany, some years ago now, which did support our data, pregnancy rate in Mas after application of GNRH, so that would be worth a read and.
John Newcombe, who was the my co-author in the first study we did, he's continued to publish on this subject, mainly along with, with Andy Peters, who was back in the day from the original working with with Intervet, the drug company, and John's added together a lot of his work, to show, really, if, if he looks at his data over a four year period on, that is a large number of mayors. 2,346 mares. To determine the effect of a single dose, either 5 mLs or 10 mLs, a whole vial, .
On pregnancy rates and, and the GNRH was given somewhere between 8 and 12 days after service. I, I generally gave it after day 10. I, in my opinion, in, in our practise, that's when we give it.
We give it 10 days after ovulation. Rather than 8 to 12 days after service. It depends how accurate it can be if you're visiting your stud farms every day or, or whatever, how, how, how accurate you can be in knowing, well, this is, 10 days from ovulation.
If you're only going to the stud farm every 2nd or every 3rd day, well, you can't be that accurate. Fortunately, we can visit most of our breeding farms every day, so we could be accurate to within a 24 hour period. And even in, you know, when John takes this large number of mares, there is a definite increase in pregnancy rates using receptile, Berrein.
And you know, 5 years ago now, he wrote a 6 years ago now, 6 or 7, he wrote a, a, a, a review paper, wonderfully entitled The Berrein Enigma trying to postulate or or theorise how this treatment may help decrease embryo mortality and reduce the incidence of early pregnancy failure. I'll refer you to that paper. All I wanted to really make the point, for you today is think about using.
Boocerein in your practise to reduce the incidence of early pregnancy failure. We do, which doesn't mean you should, but we certainly use it in our practise, extensively. Any man with a history of early pregnancy failure, or that may be a likely candidate, 1617 being bred for the first time, a uterus with a large number of endometrial cysts, whatever.
All mayors on the second cycle onwards, if the owner's content for us to do that, obviously. You know, if we're working on this 65 to 70% per cycle pregnancy rate, we've cut out a lot of mayors by we get to the second cycle. So we will try and use it routinely, all mayors on the second cycle onwards.
So, I'm just putting that there for now, go back and have a think about it over time and, and see if you want to have a go at using Boocerein, the GNRH analogue in your armoury for trying to reduce early pregnancy failure in mares. What, what more people use to, in an attempt to reduce early pregnancy failure is, is supplementing them with progesterone or progestogen. Probably equally controversially.
So let's, let's try and put out an uncontroversial statement to start with. Progesterone is produced by the corpus luteum following ovulation. Well, I think I'm on safe ground saying that.
I don't think we've got any dissenters with, with that. Progesterone is produced by the corpus luteum following ovulation. OK, let's try another.
There's a rapid rise in the mare after ovulation until levels decline when luteolysis occurs due to prostaglandin release from the uterus. I think we'd all accept that. And I think we'd all accept that progesterone prepares the uterus for pregnancy.
So if you look at some ultrasound images are very, very important to, at the first pregnancy scan, always evaluate the corpus luteum as well. Whenever I'm scanning a mare for pregnancy, I always check the left and right ovary, and I want to count number of CLs, and I like to keep a note of how apparent they are, how obvious they are. Now, I, I don't know in what part of er country or the world you are, but .
Most colleagues, I guess, I, I know back years ago when I did breeding season in Australia, we actually had native progesterone, we, we certainly haven't had that in the UK for a long, long while, if, if I've, I've never used it in practise. For many, many years, the product, we used was the progestogen altralogist, marketed as Regumate, 2.2 milligramme per mL, 1 milligramme per 50 kilogramme body weight.
But you must bear in mind it has not got a licence for using in early pregnancy failure, it's, it's. It's an off label used certainly in the UK anyway. And recently in the last 2 or 3 or 4 years, probably now in the UK we've had compounding manufacturer, and we can get altraigist injection if for some reason, you know, perhaps there's women gonna have to handle it, so you, you feel it's safer to use an injectable product.
We now have an injectable product available in the UK. Now, the majority of scientific evidence suggests that primary luteal inadequacy is not a cause of reduced progesterone levels. I, I, I, I, I do accept that, except I'm, I'm gonna highlight you, to one paper which actually a lot of subsequent work does go back to just quoting that one original paper, so I'll.
I'll, I'll go along with that first bullet point. I agree there is a, a majority of evidence suggesting it isn't a cause. Here again is something I think is, is, is important to understand.
If we are using a progestogen, we must use one that raises progesterone levels. You know, some of the progestogens, which we hear of colleagues ask us about using, as far as I'm aware, they don't bind to the equine progesterone receptors, so they're not, I, I, I don't know what they're doing in the mare, but it's difficult to imagine they're doing anything. We do know that a renoist will bind to the equine progesterone receptor and can maintain pregnancy.
In a variectomized mare, so I think if you are going to use a progestogen supplementation, alrenerest may be the one to use. This is probably the seminal paper which a lot of people refer back to showing that there was no, you know, mayors don't lose the early pregnancy because, They get low progesterone levels. And it's an eminent piece of work, but it is one of those papers that gets recycled and re-quoted without more, original research getting done on the topic.
So I, I remain slightly unconvinced there's, there's been, More recent studies showing that that that is the case. And if you do search the literature, there are reports of low pregnancy, sorry, low progesterone levels, probably caused by premature luter regression, and those mas having the pregnancy maintained by using oral alrenergist. So I could refer you to Igor Caniso's paper in equine veterinary Journal, .
And then, very interesting, I don't know if those of you familiar with the publication Equi Veterinary Education. This was a, a wonderful article, a bit of a, a poisoned chalice, by that I mean a difficult topic for Simon Stanfley to write about, and I think he did a first class job here. So the title of the topic was do I give ourtranoist to prevent pregnancy failure.
And it really is well worth a read and. I congratulate Simon on, on going through it in a very methodical fashion and it's very, very interesting. His conclusions were luteal insufficiency as a cause of early embryonic death in the mare is rare.
OK, yep, Simon, I agree, it's rare, but it's not unknown. The widespread use of altranogestine mares that fail to conceive or carry a pregnancy term is not evidence-based. Yeah, okey dokey.
However, in selected cases, give some examples, the use of atranogest has a positive effect on life foal rates compared to untreated controls. Yeah, good, it's a, it's a good paper. I, I would say yes, I, I, I, I accept all of that, that gets said about use of progestogens, but.
Our practise does have a large number of, of problem mares. Older mares, mares prone to fluid pooling, production, after breeding, and. Early pregnancy rate across the board is certainly below.
What you would expect as an average for any mare, let alone for probably the type of, you know, we have a slight bias to dealing with a large number of problem mares, and despite that, we have an excellent, an excellently low incidence of early pregnancy failure in our practise, and I'm convinced it's due to our quite aggressive approach, starting from post-breeding management. What we do with the mares after breeding, through to whether we give them a Borelin injection, through whether we put them on progesterone, as well as things like, you know, making sure if they need a Calic, etc. They have that, so.
We do use a progestogen in our practise, we use it in mares with history of early pregnancy failure, a mare with edoema at the first pregnancy scan, and a mare with an inverted commas, poor quality corpus luteum at the first pregnancy scan. And you know, that there isn't a set protocol, but I'll give you our protocol. Why did I pick this?
Well, you know, I, I, I'm well aware we probably could stop the progestogen supplementation earlier, in fact, of course, many people would argue we don't need it at all. But what clients in a commercial situation don't like is change. They don't like one veterinarian from the practise going and saying, well, Keep the mayor on this supplementation till day 90, then go twice a week to day 110, and then you can stop it.
Probably, that's gonna be OK. But what I found was different clinicians in the practise were having slightly different ideas about how to, Give the progestogen supplementation. I said, folks, I think it's gonna be better if we have a consistency here.
I accept it's all a little bit up in the air about whether we need it in the first place, whether we could just give it for 2 or 3 weeks, whatever, and that's a perfectly reasonable view. This is what I think is a reasonable approach, but that doesn't mean to say it is, of course. So we give it daily until day 100, every other day until day 120.
Twice weekly until day 140 of pregnancy. That, that, that's it, and we produce a data sheet or not data sheet, sorry, an information sheet for the mare owners outlining that, so I can refer you to that if you want to. I, I know from, questions I got asked with, with webinars along these topics before, some people say, well, when, when do you begin the progestogen supplementation?
Well, if I'm using it because it's a mare I think is gonna be at risk for early pregnancy failure, I would wait till day 56 after breeding. I don't like putting the mare on progestogen supplementation too soon. After ovulation, I like that uterine environment to get nice and healthy and free from infection and inflammation before artificially increasing progesterone levels.
So I would wait until day 5 or day 6. Of course, in many situations, we administer the atranogist when we do our first scan of the mare, and we either see a widespread edoema pattern, fluid around the uterus, or an indistinct corpus luteum. So, quite a lot for you to think about there, quite a lot of controversial things, whatever, don't, here's a happy bunch of us as equine reproductive clinicians, I, I, I hope you all enjoy the webinar and found something useful out of it, and.
We'll call that, we'll call that a day. Thank you very much as it says there for your attention.