Hello and welcome everybody to our webinar this evening, which is brought to you by MSD Animal Health in partnership with the webinar vet. This evening, Jonathan Pycock is going to be talking to us about ovarian abnormalities, practical tips for dealing with problem mares. This is the first in a series of equine webinars that will be brought to you over the next 12 months.

Jonathan is a recognised RCVS specialist in equine medicine reproduction. Jonathan is universally known throughout the veterinary equine profession. He has been a member of Council for the beaver for 6 years and is responsible for the longest running beaver course for reproductive ultrasound course, which has been running every year for the last 25 years.

In 2012, he He took up an appointment as one of 3 equine claims consultants for the Veterinary defence Society. Jonathan has had a long-standing commitment to continuing professional development within the equine profession and delivers approximately 65 days of CPD per year in both the UK and internationally. An experienced horseman with a broad experience, Jonathan has taught, participated in research programmes, and continues to work in clinical practise, setting up his own practise from scratch in 1997.

So, before I start, I'd just like to once again thank MSD Animal Health, for working in partnership with Webinar vet to bring you this series of equine webinars. And without further ado, I shall mute myself and pass over to Jonathan. Thank you very much, Jonathan.

OK, thank you very much. We're going to talk today about ovarian abnormalities in the mare and try and focus in on some practical tips we can use to deal with problem mares. You might ask why we're gonna talk about ovarian abnormalities.

Well, there are very significant part of the problems we have to deal with on a daily basis if we're involved in equine reproduction, and that could be whether we're a specialist stud vet dealing with large numbers of mares on a thoroughbred or warm blood establishment, or we're a practitioner who does less may work, perhaps just monitoring one or two mares their premises or at their clinic for artificial insemination. But whatever and and and however big or small your involvement is with equine reproduction, variant abnormalities are going to be a significant part of the problems which you have to deal with. So for that reason, I think it makes a most worthwhile topic in a webinar such as this.

Probably as a start point, we should get some sort of problem list, a bit like the sort of bucket list in that movie where you have your list of things you want to do. I mean, the problem list is a list of the problems we can face in the equine ovary, and I find it useful, it's always important, I think when people talk about different conditions, to, to, to give some sort of indication. Of whether these are common, very common, not so common, or pretty rare, and I, I find a split into common problems and less common problems useful on that basis.

And it's no coincidence that if we look at the common problems on the left hand of the screen there, right at the top, I've chosen to put anovulatory follicles. Because they really are the most significant ovarian problem. Possibly the most significant problem we face if we consider the ovaries, the uterus and the oviduct in the mire.

And we'll try and explain throughout the next 45 minutes or so why that's the case. And then what we can do as practitioners to deal more effectively with ovarian problems. We're going to spend most of the session on the anovulatory follicles, and we'll consider both the hemorrhagic and ovulatory follicles.

We'll explain the difference between them and persistent anovulatory follicles, and hopefully that'll clarify some things for you in this very important area. There are also several other common ovarian abnormalities in the mare, persistent corpus luteum, premature regression of the corpus luteum and an absence of follicular activity. These are all important topics and.

Would be well worth the subject of a of a of a of a presentation in themselves. In the time we've got available today and to try and get all the points across, in a useful fashion about anovulatory follicles. I'm going to concentrate on those because I find they're a very hard subject to write about in books, and, and you really need to hear them presented in a, in a lecture or a conference environment, whereas topics such as persistent corpus luteum, premature luteolysis lend themselves more readily to being written about in, in my opinion anyway, so we're going to take that approach.

Less common problems it doesn't mean they're not important, and that's a big thing to understand. Ovarian tumours are a very important ovarian abnormality, but they are pretty common. You know, in our practise, we maybe had 8 900 mayors at some years looking after, and we may see one tumour, we may not.

Another year we might see a couple of ovarian tumours. We may get some mayors referred into us with an ovarian tumour. But the point being, very, very rare.

So they're an important problem, but they're quite rare. The other thing about them is. It's pretty standard what's been said about the ovarian tumours, and again, I don't think we need to spend too much time in this presentation on ovarian tumours, although we will touch on them, particularly with the point of view of recognition and diagnosis.

Because when we're talking about hemorrhagic anovulatory follicles, and indeed persistent anovulatory follicles, it becomes important to make that distinction between them and an ovarian tumour, for obvious reasons, which we will talk about. So, there you go, that's what we're going to focus in on anovulatory follicles. That's gonna be our most of the next 40 minutes.

Before I can get into anovulatory follicles, which are essentially a form of ovulation failure, I think it's worthwhile just in 2 or 3 slides, making sure we're all up to speed about what normal ovulation is. It's like anything, if we're attempting to demonstrate or talk about what's abnormal, if we haven't all got fixed in our mind what the normal situation is, well, then it, it doesn't. It doesn't sound or it doesn't work out as good a technique or or or ability to present the abnormal.

So, normal ovulation. We all know that what we measure when we're monitoring a mare through a follicular phase through estrus, is follicle size. We've all known that, we taught it at college, we read it in our books, we practise it in our daily lives.

The point I want to make about measuring follicle size is, is this. Yes, it is a good thing to do. Yes, it's very useful to do.

But I think there's a tendency amongst veterinarians to carry the importance of measuring follicle diameter right up to the last 24, 36 hours before ovulation and use it as a guide of when that follicle will ovulate. And I think follicle diameter isn't. A useful tool for for predicting ovulation within a 24 to 36 hour time frame.

That might sound a little unusual and it's worth explaining what I mean by that. And to do that, let's have a look at this ultrasound image on the screen here. We've got a 2.8 by 2.9 centimetre follicle.

I've measured it twice, you know, top to bottom and left to right, which we don't normally do in practise. We would just take the one measurement and as you can see in the bottom left corner of the ultrasound. The measurements there show you they're only differing by millimetre, which could just depend on where you've chosen to put the callipers.

The point being at this stage of the follicular phase, probably the 2nd 3rd day of Eus, we've got a perfectly spherical follicle, so the, the two diameters are going to be the same. So measuring follicle diameter when the when the follicle still is retaining this spherical shape is an excellent idea and very, very accurate. Contrast that with this ultrasound image, which is a follicle within 36 hours of ovulating, we would all take a look at that follicle and think, yeah, well, within 36 hours this follicle is ovulated.

And we've got to use some of the other ultrasound features which we're going to talk about in the subsequent slides as our predictor of when this follicle will ovulate. To measure follicle size. I don't think it is important at this stage.

Whether that follicle is 40, 41, 43 millimetres, I don't think it matters. So, as we say there, I don't think the diameter measurement is as useful when we're in this 24, 36 hour time frame before ovulation. If you think about it, it's pretty obvious, really.

I mean, the follicle has become soft and it's lost that spherical shape. And we could choose where we put the callipers. If I, if I put the calliper from there to there, well, we'd get a different measurement to whatever we get in the calliper.

Direction we've got on the actual image. So, you know, when colleagues ring up and say, oh, are we, are we close to ovulation, it's gone from a 41 to a 43 millimetre follicle. I aren't as concerned about the accurate measurement of the follicle diameter at that stage.

I generally would just be recording those follicles on my sheet as 40 millimetre plus. If you ever see that on one of my Mare records, it means, well, we're in the 24 to 48 hour time frame of that follicle ovulating. So I'm going to take a look.

Yeah, 40 millimetres. I don't care whether it's 41 or 43. I'll be looking at some of the other features we're going to talk about in a minute.

And My, my feeling or opinion over many years would be, I truly don't think diameter changes in this 48 hours before ovulation. So importantly, as a guide of predicting accurately impending ovulation, I think you should move away from being dependent on follicle size. We're going to go on some of these other.

Changes. What are the other changes? It's a bit of a busy slide here because often I'll have things moving in on these, but it looks better on the webinar sessions to have the whole slide up there at the outset.

So if we go through these, starting in the Top left hand side flattening, we're familiar with that. The flattening of that dorsal margin of the follicle by the pressure of the ultrasound transducer in the rectum, we all know is an indicator of impending ovulation. Thickening of the wall, you can see there 34 millimetres thick compared with that dorsal wall there.

So the follicle wall thickens, and most of us these days I'm sure are working with these lovely crisp, digital ultrasound machines, and if you set the machine up correctly, they will allow you to see these rather subtle ultrasound features which are much better for predicting ovulation than. Simply follicle size, there's an appearance of an anechoic layer in that ventral margin, often easier seen in that ventral margin, almost as separating away. That again is an indicator within 24 to 48 hours this follicle is going to ovulate.

Of course, size, yes, it's going to be over 35 millimetres in most cases. All rules, especially rules about mares, are made to be broken. But by and large, a follicle in a typical warm blood or thoroughbred mare is going to be in excess of 35 millimetre diameter when it's ovulated.

Now, the last ultrasound feature which I haven't mentioned yet and left till last, is this, the appearance of these small ecogenic particles in the follicular fluid. And we're gonna come back to this appearance because When we have a follicle which doesn't ovulate, as it should do, and it becomes a hemorrhagic and ovulatory follicle, one of the ways we recognise those is by the widespread appearance of these ecogenic particles. The difficulty is that to some extent, the appearance of ecogenic particles in that ventral margin is a normal indicator of impending ovulation.

So it becomes a question of degree. When is it normal to have these ecogenic particles, and when does it become abnormal? And that's what I want to try and get across to you in the subsequent slides, and that's why I say I think this is a topic which lends itself very well.

To these webinar sessions rather than trying to read it out of a book. So I'll attempt to over the next few slides, convey to you what I mean by trying to decide whether we've moved from a normal ovulation just with the appearance of these ecogenic particles, or they've taken over the follicle, as it were, and we've moved out of a normal ovulation into an abnormal hemorrhagic follicle. Flattening, we all can recognise flattening if you look at that dorsal margin, the pressure of the transducer is really flattened off that follicle compared with the ventral margin.

And there's a typical diameter, although as we've said, in the 36 hours before ovulation, follicle diameter is not so important. Nonetheless, we're going to get a typical 42, 43 millimetre size in a thoroughbred or warm blood mare. An increased ecogenicity, I think you can all agree, you can see that there, that increased ecogenicity of the follicle wall.

That's an indicator of impending ovulation. Even if we see that increased ecogenicity, but the follicle has remained relatively small, as actually is the case in this follicle. This is not, I haven't put.

Measurement in, but it isn't a particularly large follicle. But you can be pretty sure this follicle is within 24, 36 hours of ovulation. And one of the features I used to make that decision is noting this increased ecogenicity of the follicle wall.

Again, we get these usually in the ventral margin when it's indicating impending ovulation. These small ecogenic particles, and we're going to return to this theme when they become more widespread throughout the follicular antrim, and we may have moved in to a hemorrhagic follicle. To a Then we get, just ignore this little rectangle box for a minute.

I'm going to come back to that, but we get an out pouching towards the ovulation fossa. If you all remember your anatomy of the equine ovary, ovulation always occurs at this indentation in the ovary. We call the ovulation fossa, and that's where the the first part, the oviduct, the infundibuum is attached to the or very closely applied to the ovulation fossa, and that helps ensure the oversight in the mare is never lost.

It's always sucked up, as it were, by the first part of that oviduct. And, and that's why we get this characteristic out pouching or becoming pear shaped when we're in this 24 hour, 36 hour, time frame before ovulation. Now to mention what that rectangular box is, and that most of you or some of you will know, I, I, I'm sure it's, it's where we're looking at the blood flow using the Doppler facility on our ultrasound machines.

A lot of the ultrasound machines in everyday equine practise now have a Doppler facility, and it's very exciting and pretty new, and we don't know all the information about it yet, but there's no doubt that Our understanding of, of, of some problems in equine reproduction and in particular, Hemorrhagic follicles may well be improved by using the Doppler facility to check the blood flow. So, in a year or two we might have some more information about using Doppler ultrasound to detect and predict hemorrhagic follicles, follicles which aren't going to ovulate. So that'll be.

Something for another, another day. So, that's a little bit about how the follicle changes as it approaches ovulation, and obviously then at ovulation, there's a collapse of the follicle and the filling of the follicle with blood. And of course the blood as it begins to solidify and clot and fibrin appears in it, changes from the black fluid of follicular fluid, which allows most of the ultrasound beam to be passed through.

We move into this more solid, more dense structure, and that of course reflects a significantly greater proportion of the sound from the ultrasound transducer. Therefore, we see it on the ultrasound screen as Shades of grey with little anechoic lacuna in, and, and some of them we'll look at will have fibrin strands. But the point I'm going to make over the next 3 or 4 slides is many, many forms of the early corpus luteum.

Why do I want to make that point? Well, because some hemorrhagic and ovulatory follicles look pretty like a normal corpus luteum. And it's very, very hard sometimes to make a definite judgement as to what's a normal corpus luteum and what's been a hemorrhagic and ovulatory follicle.

And if the early corpus luteum was more uniform in how it appeared, rather than having all these normal variations, it would make the detection of a hemorrhagic follicle much easier. If you look at these ultrasound images, you can see these are two perfectly normal corporal lutea, but they look very, very different on ultrasound. Here's one with really just a 4 or 5 millimetre luteal border and some hemorrhagic flex in it.

Here's a much more solid. A much more dense corpus luteum, both perfectly normal and both exactly the same, in terms of, you know, they will both have released the site. They're both reproducing progesterone, so fertility wise, they're just the same, and hormonally wise, the mare will behave just the same.

But very, very different in a normal appearance, and that in, or that creates part of our problem for trying to decide when we've moved into a. Abnormal ovulation. And again, like I say there, we're hoping over the next few years, we may get some useful information from measuring the blood flow to these follicles.

And if we can characterise the blood flow to a normal corpus luteum, and we can see if that's different to the blood flow in an abnormal corpus luteum or a hemorrhagic and ovulatory follicle, that might be very useful for us. So. With the Dopper it's a little bit of watch the space.

Now back to the here and now. Well, probably just about the person on the planet who knows more about anovulator follicles will be a good friend and colleague of mine, Pat McHugh from Colorado State, and we were lucky enough to get him to write the chapter on anovulatory follicles or ovulation failure in our current therapy book, and In that section, Pat puts a figure of 8% of cycles have an ovulated follicles. So guys, that should make you sit up and take notice.

I mean, you know, if we bang on about something which has an incidence of 0.05% or 0.5% even, well, OK, it might be very, very important, but hey, we ain't gonna see it very commonly.

Not if we're talking about something with an 8% incidence. That's why I said at the beginning, even if you're the veterinarian just dealing with small numbers of mares, you are gonna come across these ovulation problems, these failures of ovulation. And.

Over the last 3 or 4 years, we've had a look at some of our data, and I think we can nudge that figure up a little bit. I think we're approaching it as occurring in 10% of cycles. Whether it's going to keep on increasing, I don't know, but certainly, whatever, it is a significant problem.

And within that population percentage of 10%, certain mares are particularly prone to the problem, and they do create severe headaches for us, and we'll, we'll, I'll, I'll try and pass on over the years, some of the little practical tips I've found which may help us with these problems. We've got a couple of ultrasound images, bottom left, we've got a anovulatory hemorrhagic follicle there, and we've also got an earlier looking anovulatory hemorrhagic follicle there. I'm gonna explain the difference between those two as we go through the next few slides.

What's important to understand, and, and I don't think this is always fully appreciated, is within that 8, 10% of incidence of ovulation failure and ovulatory follicles, we can break these follicles down into two types, and it's very, very important to understand this because we manage. These two different types of ovulatory follicles in different ways. Now, the majority of them, in fact, we could say the vast majority of them, 85% in most studies that Pat McHugh and others have done.

85% for hemorrhagic and ovulatory follicles. We often abbreviate that in the literature when we're writing to halves, HAFSAs. And what they've done is they have luteinized.

Now what we mean by that, just so we're all clear, is they are going to produce progesterone. So hormonally, what will happen? The mare will go out of estres if you're able to tease her with a stallion.

He edoema pattern will disappear from the uterus, cervix will tighten up. And if you took a blood sample for progesterone, it would be typical progesterone levels of a luteal mare because to all intents and purposes, that's what these mares are. They are luteal.

What they haven't done is release the oy, hence the term. An ovulatory follicle, but they are hemorrhagic, they've undergone luteinization. But whilst it's the majority of them, it is not them all, and I think some people forget about.

The 15%. Of anovulatory follicles that don't have haemorrhage into them. They remain as follicular structures.

All they do is enlarge, maybe grow to 6789, even 10 centimetres in size, but remain pretty much anechoic black on the ultrasound screen. And what they've done is they've not ovulated, they've not released the oocyte, but hormonally they're not producing progesterone. So.

If you've got another follicle somewhere else that has gone on to ovulate normally and produce a corpus luteum, well, you will see the typical endocrinology changes of the folli the luteal phase. But if you haven't got another ovulation that's occurred, well, these mares won't go out of estrus. They won't lose an edoema pan, and they won't have the cervix closed because hormonally, this 15%.

Are remaining under an oestrogen steroid hormone balance. So it's very, very important to keep clear in your mind that there are two types of anovulatory follicles. One, much more common than the other, but don't forget these persistent follicular structure.

Now it would be good, wouldn't it, if we could predict these follicles that were destined to fail in terms of ovulation at an early stage. Bad news, we cannot do that. It's pretty well accepted that the initial growth patterns in follicles which are going at some point down the line to become anovulatory are usually normal in appearance on ultrasound, palpation and so on and so forth.

And similarly with the uterus. If we scan these mares, we see the very typical endometrial folds as you can see in the bottom ultrasound image here. A typical cartwheel appearance of the mare in a follicular phase under oestrogen dominance in an absence of progesterone, and that is the situation in the early stage of a follicle which is destined to become an anovulatory hemorrhagic follicle.

So a problem for us, we cannot use how they appear in the early stage as a method of detecting them. It remains to be seen whether Doppler may give us an advantage with that, and I think it's too early at this stage to say for sure. Sure So how do we begin to recognise them?

Well, at some point they do diverge from the normal follicle. And I think the two features which, which alert me to a possible, and I'll use the word possible, I still don't think at this stage we can be definite. The two things which alert me to it are an increase in size above the 40 to 45 millimetre we would expect in a typical mare just on ovulation.

They become maybe 50, 55, 60 millimetres, even more in diameter. And the ecogenic particles that we note in the ventral margin of the follicle, when ovulation is very, very close with the thickening warm those other features we talked about previously. Well, the ecogenic particles, the echoic particles become more widespread throughout the whole of the follicular antrim.

And if you look at this ultrasound image on the right. This is an abnormal follicle. I'm I'm hesitating a little bit because you will see mares which, if this remains at 40, 45 millimetres with this amount of echoic particles in it, a small percentage of those mares the next day will have almost reverted back to this left hand appearance and look normal and Not everybody agrees with that.

I think other colleagues are more definite that once a follicle has progressed to this stage, well, it's game over. This is going to be a hemorrhagic anovulatory follicle. I just aren't you sure that's the case.

I think once you perhaps had even more ecogenic particles than we see here, . Or a bigger increase in size, well, that's gone beyond the point of no return, and it is going to form an anovulatory follicle. But earlier on I think it's difficult to know for sure.

Now, of course, it's like everything in life, once we get further down the line, well, the situation becomes easier. In these two ultrasound images we've got here, the haemorrhage that's occurred has begun to organise, and we get a more or less solid appearance to it. Sometimes, as in the image on the left, we have a sort of cobweb-like spider's web-like appearance of these.

I'm, I'm guessing there's strands of fibrin in there. And remember, the OSite has been trapped in here, not being released, . But hormonally, progesterone's being produced by these structures.

So these are hemorrhagic and ovulatory follicles, the luteal type of structure. And similarly here on the. The right and you know, whenever I see an ovary looking like this, I feel, you know, how difficult it must be for colleagues who don't ultrasound too many mes and see something like that which looks incredibly strange and oh, what's going on here, you may think.

And there's a temptation, oh, have we got a granulosis, so tumour, have we got something we need to remove and. You know, if you're in a big practise where there's a surgeon who's itching to get out his or her scalpel blade and remove the ovary, oh, I think this is abnormal, better remove this ovary. And you know, unfortunately, that's nothing, there's nothing more to treat it than a shot of prostaglandin, as we'll talk about in the slides when we move on to treating and managing and dealing with these structures.

So there we are. Once we've progressed onto the 2nd, 3rd day of of the formation of a hemorrhagic anovulator follicle. Well, it becomes a little bit easier to know, yes, we have had one of these structures.

But of course, you might You might have already sent the mare off for covering. You might have inseminated your mayor with the chilled semen. You might even have ordered or put in the expensive frozen semen.

And if we see 2nd, 3rd day, these sort of structures, oh, I'm thinking, not going to have much chance of a pregnancy, but don't rule it out. We're going to come to that as we move on, because, well, I won't spoil the surprise. I'll tell you why.

When we get to that section. So hopefully we're all looking at that, we're all seeing this progression into 2nd, 3rd day, a little bit more obvious we're into one of these abnormal follicles. So, let's come on to the treatment or management of these hemorrhagic anovulatory follicles.

We're still talking about the 85% of anovulatory follicles that undergo haemorrhaging them with the consequence that they behave like luteal structures. And here we can see on the left, this would be a hemorrhagic anovulatory folly. And if we wait at least 7 days for them to have formed and give a full dose of prostaglandin on 2 successive days, they should respond to that prostaglandin.

That's what I used to do with these structures. Why did I do that? Well, it was back in the day when we thought you had to wait till day 7 before a corpus luteum was responsive to prostaglandin.

We now know that might be the case, in fact, isn't the case. And why did I say give a full dose on two successive days? I had the impression that it was harder, more difficult.

They were more refractory, these structures, to prostaglandin. I'm not sure truthfully whether that is the case, and certainly latterly, I, I, I've changed that approach. I'm giving a more less of a dose of prostaglandin and only giving it on one occasion after day 6 or day 7.

And we'll we'll, we'll move on to that. So that first bullet point or that, that's what I, I used to do, probably, when we were 1st 8, 10 years ago coming across these structures. And I put in the yellow, is this such a good idea?

Well, you know, I'm not so sure it is such a good idea. I don't know about you, but on a lot of the stud farms we go to, if they've gone ahead and bred the mare, and I then subsequently think she's formed one of these hemorrhagic anovulatory follicles. Stud farm guys, she goes, well, Doc, hold on here.

Look, let's just scan her at 14 days and see if she's in full or not. Let's not go messing about, giving a prostaglandin after 7 days and and and and re-breeding and let's just hang on and see, maybe it wasn't hemorrhagic follicle, you know. Let's not give a prostaglandin.

So that's a very good reason. Maybe we said the recognition of them is hard. Maybe what I thought was a hemorrhagic follicle has in fact been a normal corpus luteum.

And I think you've got to. Consider that as a possibility, no matter how experienced you are. That's a little bit different to to many other colleagues who who who a great deal of experience, they will present at meetings around the world.

They are more dogmatic that they can definitely recognise these as hemorrhagic follicles, and I'm just throwing in a note of caution with with the feeling we have there on the the left there. I don't think. Yes, you can be pretty sure, but yeah, it's just always a little sneaky feeling of me thinks, well, there could have been a normal ovulation there, so let's hang off.

If we've bred that mare or if we've inseminated that mare, let's hold off. Giving her the prostaglandin in. Look, we're going to be scanning her at 14 days anyway, even if we PG her at day 7.

Probably follicle diameter isn't going to be a lot bigger by day 14 anyways. So we're in no worse shape in terms of rebreathing that mere through giving a prostaglandin at day 14, which I wouldn't normally do. I wouldn't normally give.

A prostag gland into a me on, the first scan at 1415 days if I thought she wasn't info. But if I've only got one, if I'm pretty sure there's only been one ovulation or, or lack of an ovulation, there's only been one, hemorrhagic and ovulation follicle form where I sometimes break that rule, and I might give them a shot of prostaglandin at day 14. But if I'm gonna do that, there's something I've got to be very careful to look for in, in those two ovaries of that mare.

Have a think about what that is, it's in these sort of webinars, I can't sort of look at one of you and ask you, but, but hopefully at home or wherever you are, you're thinking about this. What is one of, They, not problems wouldn't be the word, but one of the big features that happens in terms of ovulation in the mare, particularly the thoroughbred mare. Now I hope you're shouting at me there, multiple ovulation.

Come on, it's 30, 35%, at least in the thoroughbred now, and it's going up. So a tremendous number of mares in percentage terms will have a second ovulation. So if you've got hooked in on a, on a follicular phase of scanning and scanning this particular follicle, and whoa, then you think.

Common form the hemorrhagic and ovulatory follicle. PG are in 7 days. Whoa, you turn over and look at the left ovary, you see, oh boy, there's been a normal ovulation there, so may well be in fault.

So that's another reason. I don't give Prostaglandin even when I'm pretty sure there's been. A hemorrhagic ovulation.

OK, I'll scour both ovaries really carefully to look for a second corpus luteum or, you know, a normal corpus luteum or, or hopefully preceded by a normal ovulation. So very, very important to bear in mind this high likelihood that the mare may have a second follicle with a normal ovulation. So the two reasons, if the mare's been bred, I won't give prostaglandin on day 7.

Even when I'm pretty sure there's been a hemorrhagic ovulation, the fact that I think you can't be 100% sure, so the recognition question, and possibly more importantly, well, there could be a second, perfectly normal ovulation have occurred, and we could have a pregnancy ensue. So that's just my rule. If you've bred or inseminated the mare.

You think she forms a hemorrhagic follicle, let it run on to 14 days and scan her for pregnancy. That will be my. The way I would go with them.

Now, we're gonna have a look at some video clips of hemorrhagic follicles in a wee while, but just before we get there, I want to just go back to that smaller percentage, the 15% of anovulatory follicles that do not luteinite. They remain as follicular structures because we have a tendency to forget about those. We all think we form these hemorrhagic anovulatory follicles.

Now obviously with these non-luteinis follicular and ovulatory follicles, well, prostaglandin isn't gonna have any effect, is it? Why, why would it? We can try and induce ovulation or, or, or possibly we should use the term advancement for these agents.

We can use Coriolon, HCG or Deslorein. In its various forms. I don't have that good a success with use of these ovulation induction agents with these anovulatory follicular structures.

I improve the ability of them to respond by priming the mare with a 12 day course or 1012, 14 doesn't have to be precise, of the progestogen altranoestreguate. I find if you do that, it's, I guess it maybe mimics the normal CL and perhaps the theory is when we withdraw the altraages, the next day give them an ovulation induction or advancement agent, more likely that follicle will ovulate. These things usually will spontaneously regress, so that's all fine and dandy.

The difficulty is it can take 4 to 6 weeks, so we're losing a significant chunk of the breeding season to these wretched things. So I have resorted, and I appreciate this isn't, open to, to, to all of you in practise, but I have resorted to using a transvaginal puncture with the same apparatus we use. You can see it bottom left here, bottom right, sorry, .

The same instrument we used to aspirate our sights and and and puncture 40, 50 day twins. I, because we have this, in our practise, and we've got the experience in using it, I will sometimes transvaginally puncture these follicular structures, just to physically reduce them and Hopefully, make the, the, the, the ovaries rebound into normal cycling. So, although they're less in percentage terms compared with the hemorrhagic and ovulatory follicles, they can actually be more difficult to get rid of.

So, please don't forget about these 15% of non. Follicular structures. Maybe we'd have better success at preventing an ovulatory follicle formation if we knew what caused them, and there's a few things getting written about in the literature as being potentially the cause of them, insufficient gonadotropin stimulation, or maybe the gonadotropin receptors in the follicle malfunction somehow.

But I think if the truth be told, we don't really know what the potential causes of these anovulatory follicles are. Oh. We know there are risk factors.

Certain mares have a high incidence of them. Mares which multiple ovulate, you might think that's obvious, but it's quite nice to to see it written up in a lovely paper from Wananga and Johnny Newcombe 2 or 3 years ago, and they found that mares with the highest hemorrhagic anovulatory follicle incidence were mares with the highest multiple ovulation rates. There's a feeling that age is a risk factor.

I've put the question mark in because the juror's a little bit out on that one. But I think by and large, we accept that they are more common in older myths. The stage of the breeding season.

Again, there's a little bit of a split opinion. I, I, we initially used to call these autumn follicles and people thought, oh, they might be more common in the sort of autumn of the breeding season. Paper again, coming out of John Newcombe's lab in 2010 showed actually, that probably isn't true.

They are common in the autumn. They're commoner during the peak of the breeding season, i.e.

The highest months of follicular activity. So, not quite sure about. Stage of breeding season in terms of their risk factor.

It seems to make more sense to me to go with the idea mentioned in this paper that if we're having more follicles ovulating, we're going to have more hemorrhagic and ovulatory follicles form. That seems a logical. Deal to me.

If we use certain hormones to induce these stress and then ovulation, are they a risk factor for hemorrhagic and ovulatory follicles? Again, paper from Herango and John Newcombe would suggest very strong evidence for that. I've put the strong in brackets because.

Other workers don't find that link between hemorrhagic follicles and prostaglandin analogue. I was lucky enough at a recent meeting, speaking with Pat McKew, and Peter Diyles, and we were talking about this very point, and I went back and put strong in brackets here, because both of those two colleagues didn't feel there was this strong link between using prostaglandin and Hemorrhagic and bile follicles. So it's something you'll have to make your own mind up a little bit.

Still in, in my, my mind, if I'm suspecting Amir is repeatedly forming or I'm knowing she's repeatedly forming hemorrhagic and ovulatory follicles, I will. Try and back off using prostaglandin, at the very least I'll make sure I use a low dose. I mean, what seems to be the case is if we're whacking in large doses of prostaglandin above 250 mcg.

Say of of chlorostenol of estromate. Well, that might, and let's say might increase the risk of these follicles. So maybe back off using these high doses.

Same if we use corrilo when the follicular diameter isn't big enough. 25, 28, 30 millimetres could be a little bit early to be using Colo and may increase the likelihood of a hemorrhagic unovulatory follicle. But I've put in that last bullet point, maybe we only see that effect in certain breeds, because certainly not everybody would agree with this feeling, this link between prostaglandin usage and hemorrhagic and ovulator follicles.

So it's something I'd suggest you think about in your practise and, and see whether you think it's it's causing risk factors. I certainly am along the lines of There is a potential for, for increasing the incidence of hemorrhagic and ovulatory follicles if you go injecting mare with too larger dose of prostaglandin. And we, we all can see.

You know, we all can look back on some of our mayor records. I see mayors I've looked at once a week, and all I've done is jab them with prostaglandin once a week, and you don't seem to pick up that you're not managing those mares well till the end of the month and you look back and say, oh gosh, all I've done once a week is inject this mare with prostaglandin. You know, I should maybe just back off a little bit and let a cycle of cells, so.

Just something to think about prostaglandin as a risk factor for inducing a hemorrhagic anovulator follicle. So, I, I, I, I mean if we could call this what everybody likes, these take home messages, these practical tips for management. What do I want to do to bring everything together?

Well, I think the recognition of hemorrhagic and ovulatory follicles is not easy. I think some of them really resemble a follicle that's going to ovulate normally. So I think it's very difficult to recognise.

I would avoid prostaglandin and an ovulation induction agent, or if I can't avoid prostaglandin completely, I'll maybe use a very low dose, and we know now from work of Carlos Pinto and others that we can use really very low doses of prostaglandin to be effective. 1/10 of the manufacturer's recommended dose. So maybe that's something to think about.

And always, always remember, you know, mares, particularly thoroughbred mares, but warm bloods as well, have a big increase of, of, or a big incidence I should say of multiple ovulation. So we may well have a normal ovulation somewhere, . And if we bred the mare, OK, we won't get a pregnancy from a hemorrhagic and ovulatory follicle, but maybe we will from the normal ovulation.

So just bear that in mind. Multiple ovulation rate is so high in mares, we may have a normal ovulation somewhere that has eluded our. Action So just to finish within the sort of the last 555 minutes or so before we have some questions, let's have a little look at a case study.

And this is colleagues kind of email me with cases, so this is just a case we've taken from what I've been asked about over the years, and it illustrates a couple of nice points of how we should manage these myths, so. It's always interesting to use actual cases, I think. Here we had a colleague who was managing a 16 year old warm blood mare that was was was all every year inseminated with frozen semen.

Now they decided to look at it during the foal heaters late in the season. Oh, interesting. I always think whenever I'm getting these little snippets of information, part of the story, mm, interesting, fair enough, ski.

I wouldn't care how late it was in the season. In my book, I wouldn't use frozen semen at Foley, but hey ho, we'll we'll just read on with the story. I'm just putting that in for now.

She didn't show any signs of estrus, during the folate. Mm, OK. Not quite sure what they were using.

This, this is the data that that my veterinary colleague has sent in to me, so I don't know exactly what they mean by that, you know. Were they teasing the mare? Were they checking your cervix?

I, I don't know. On ultrasound scan, she had a 6 centimetre anov related follicle, on day seven and not a lot else. OK, fair enough.

That's what I'm getting told. That's what this mayor had. That's what I've got to try and think is, is going on in this mayor.

Remember, I'm not ultrasound the mayor. I haven't got any images, so I don't know for sure. I can only go on what I'm getting told, so you have to be a little bit of a sort of detective with these cases.

So. So I'm getting a bit more information. I have scanned her.

This is our colleague. I've scanned her every 2 to 3 days since the day 7, and she's now 25 days from falling, and the follicle is still just sat there with nothing moving on either ovary. Mm, OK, we're all thinking about this.

Now, these are some questions that that got posed to me. I presume prostaglandin PG will not help as no CL present. OK.

Is there anything else that might move things along? Think I might try Regumate, is it just a waste? So 3 questions come in there and then right at the end of all this, mm, never been an edoema pattern in the uterus.

Whoa, now, minute, that, that last bullet point, that makes me sit up and think. We've really got a significant finding. There has never been an edoema pattern in the uterus.

Gonna come back to that. I want you guys to think, why is that straight? Why have I perked up at that piece of information?

Why do I think that's so significant? You know, pause your old, that's what you can do now with these webinar things, you can pause that and deal with it then. So have a good think.

Why is that so significant? There has never been an edoema pattern in the uterus. OK, this is now my reply to her.

I am presuming you are describing the 15% of anovulatory follicles which persist as follicular structures without luteinizing. That's what I'm getting told, you know, I, I, I don't know. I'm not ultrasounding them here.

I've not even seen a video clip, so I can't tell for sure what's going on there. But I'm presuming they're describing the 15% of anovulatory follicles. Which don't haemorrhage into them, so they don't behave as corporal Lutia.

They just remain as persistent follicular structures, and as we said earlier in the webinar, they're difficult structures to deal with, so I'm just repeating this to our colleague. Now, something is going through my mind, and you may have to think, I, I, I maybe won't tell you, I'll just tell you what I posed in my email response back to our colleague. You must bear in mind that some luteinis anovulatory follicles only have a very thin border of lutealal tissue and a few scattered ecogenic particles.

What am I trying to sow the seed of with that 3rd bullet point there? What is going through my mind about what our colleagues say? Am I necessarily agreeing with what they're saying is going on in this myth?

Well, I maybe won't answer that now. I'll come back to it because you, you, you, you should be able to think what's going in my mindset by me asking, or making that third bullet point there. Here's gonna be the explanation to that.

Or or or may give you a good clue if you've not quite got there. Remember I said I really shot bolt upright in the seat when I got told this fact. There is no edoema.

Now on the one hand, we're getting told there's a follicular structure about. Persistent and ovulatory follicle just sitting there, but there's no edoema pattern in the uterus. Well, no, no, no, no, no.

You know, we've shown and others subsequently that you can have as, as much oestrogen as you like, but if you have any progesterone, you won't get an edoema pack. So if we've got, clearly you're gonna have oestrogen from that follicle, but no edoema pattern, what is that telling me? That tells me, guys, there has got to be some luteal tissue somewhere without any shadow of doubt.

There's gotta be some luteal tissue in this mere if she's gone through falling. Being monitored from day 7 onwards, never had an edoema pattern. There's progesterone in that.

Now, to try and get a little bit more, and some of you may know of a little bit of an obsession about getting told about this structure in the mire. You don't tell me information about one of the most useful structures. What am I not getting told about?

Don't cheat and click on to the next slide. Have a think, pause your button and pries to the first person who gets it. You don't tell me information about what?

What haven't I got told about so far? I haven't got told about the cervix. Little feed or something, you know, if any of you heard any lectures, you'll know I make this point.

I think whenever we're at a crush and I'm looking at a mayor, I have to make a decision. Is she in oestrogen or progesterone dominance? That's the point.

I've got to decide the steroid hormone balance, and I'm not convinced I was given enough information to make that decision from our colleague with that case. I in the end made it for myself. I made the decision because she hadn't got an edoema pattern.

Despite having what's supposedly a follicular structure around, she's actually in luteal dominance. She's got progesterone around. So that's why I said point number one.

Without any shadow of doubt in my mind, that mare was worth a dose of prostaglandin. I would probably remember a colleague first emailed me when the mare was 25 days. If I'd have been monitoring that mare and she'd got to 15 days, I would probably have trickled in a little dose of prostaglandin there and then.

If nothing occurs, now, this is when it's difficult when advising somebody. I, I've, I think something will occur because I actually don't think that is a persistent follicular structure. I think it's possibly a a a a diister, just a luteal follicle, which is well known in the mare, and she had a normal ovulation at the folate somewhere.

And there's a CL getting undetected in that mare's ovary. But anyways, if we stick with the idea, it is a a persistent follicular structure. Well, I had to run through using ovulation induction agents, perhaps with a regumate priming first and then occasionally having to use transvaginal aspiration, the follicle.

But guys, I want, I don't think it is, and I don't think it is a persistent follicular or persistent anovulatory follicle. I think it's just a luteal face follicle, that's sitting on the ovary and as soon as that mare gets given a shot of PG. That follicle will go on and ovulate.

And anyways, after speaking, because that's obviously what I said to our colleague, give a shot of prostaglandin. She did. She gave a shot of prostaglandin on Saturday and scanned her three days later, pointing follicle, re-scanned, she'd ovulated, inseminated her with frozen semen.

Is that a good idea? Was it a good idea to inseminate her with frozen semen? Well, yeah, fair enough.

Given prostaglandin on Saturday, 3 days later, so we've gone a reasonable amount of time from inducing luteolysis, which is, is obviously what we have. So, you know, as it happens, I wouldn't say it's always the case. Pretty often is though.

I was right, and it did have a luteal structure there. It's now got a pointing follicle. I'm not told whether it's the same one or not, I don't know, whatevers.

Re-scanned her 6 hours later, she'd ovulated. Well, it's only ovulated. I mean, you know, if you can send me that that man now, she's only 2 or 3.

You know, hours from ovulation, so seemed a reasonable go to me inseminated with frozen semen, so I just said, yeah, it was a good idea. And yeah, it wasn't a good idea because our colleague had a great result. Scanned her 15 days in foal and made a, a, a fantastic comment, which, is, is always something a good one to finish on.

She goes, Lucky really, didn't realise she might progress so quickly after PG. Well, we all know Mazel. Progress quickly depending on what follicular size is present at the time of giving the PG.

We know that. If you've got a 35 millimetre follicle and a CL, she's going to progress quicker than a mare with a 25 millimetre follicle, and so on. And then we all know mares always surprise us, that is for sure.

So we've probably got just a couple of minutes to look at some video clips if we have the . Oh, now, one more thing, just to explain the case, just in case anyone hasn't quite got it. Was this a case of an anovulation follicle?

I don't think so. I think it was just a large luteal diastrous follicle, and we did have an ovulation of foley. The ma ovulated by our colleague looked at it at day 7, and often those follicles won't ovulate and regress.

They just sit there. So if you want to have a pause at this slide, if you, if you're watching this back and just work out you're all with me with what I'm saying here. So I think this was highly likely to have had an ovulation.

And that wasn't told me. I'd kind of to work that out and that's why these cases are really good fun and you have to do a little bit of detective work with them. So I think now we are gonna go on to some video, .

Oh, we've hit a sort of IT hitch, I think, have we, with the webinar? We cannot find one. Well, no, oh, that was just a joke.

Sorry, I didn't know. Never done a joke in a webinar before, and I'm never sure whether it works or not, but anyway, I've put one in. Video clips.

So I hope you're all laughing at home. Here we see, this is, now look here. What do you think of this?

Is this gonna form a hemorrhagic follicle or not? I think on the balance it is widespread flex look in it, and 9.6 is pretty big.

Is this structure. It's going to be 789 centimetres. So yeah, I think a hemorrhagic follicle.

What about these? This is a lovely slide or video clip because it's got a normal ovulation on the left and a hemorrhagic and ovulation follicle was on the right. So interesting video clip there.

Then here, is this normal or not? You know, if we've got the surgeons in here, my sort of, you know, my BDS pal, Timmy Phillips, he'd be sharpening his scalpel blade at this, I think, to, to whip this ovary out. Sadly, you need to do nothing more than give this man a shot of prostaglandin, because this is a hemorrhagic and ovulatory follicle.

Looks incredibly weird. Sorry, you know, if you, you guys who don't scan many mares, you'll think, oh, what is going on here, it looks like something out of outer space, but it's a pretty normal looking for a for a hemorrhagic follicle. They quite often look like this, you get these cobwebby strands of fibre in it.

And then there's a slightly different spider's web one, you know, and these are the ones, you know, the surgeons are itching to remove these. They're convinced these are granulosa cell tumours. And I mean they aren't, guys, these are not granulosa cell tumours.

They're hemorrhagic and ovulated follicles. One of the keys is if you block them, I'm just banging down gently on this folli on on this this ovary with my ultrasound. You can see these things wobble around, and that doesn't tend to happen in a granulosa cell tumour.

So, you know, is this a granulosis cell tumour or an anovulatory hemorrhagic follicle? Well, if you blot it, you'll see those wiggle around, and that points you to it being a hemorrhagic follicle rather than a GCT. I, I, I can't really get into granular cell tumours because we're on time to finish now, but there's behavioural changes, you know, we, we may get a set of these palpation ultrasound we can tell because the other ovary in the tumour, so if we did see a strain, big structure like that, go on the other ovary, is it very small, likely to be a granulosis cell tumour, and hormone analysis.

Ultrasound we may get this unilaterally, one sided enlarged ovary. The opposite ovary is usually small and inactive. But a granulosa cell can be a multicysticer appearance or this more solid mass.

You know, we wouldn't probably mix up this with a hemorrhagic follicle, but the one before could weather. Hormone profile inhibit was the great marker up until we've got one even better now, which we'll just touch on to finish. Testosterone is useful to measure.

Progesterone's useful to measure in the sense that if a Mary's cycling has an elevated progesterone, generally it's highly unlikely to be a granulosa cell which. And then recently we've come across using anti-malarian hormone and there's there's a couple of labs in the UK now. I'll offer that for detecting granulosa cell tumours.

So folks, don't rush to remove a mare's ovary. Be absolutely certain it's a granulosa cell tumour, and not simply an anovulatory hemorrhagic follicle. And That brings us to the end of the, the webinar.

I've probably gone a little bit too long, but maybe we've got time for some questions now if anybody's got any. Brilliant, thank you very much, Jonathan. That was an excellent presentation.

Thank you very much. If anybody has questions, we'll move on to those shortly. I would also like to thank MSD Animal Health for sponsoring this webinar, and also I'd like to thank Jonathan for giving me a minor heart attack with the joke technical error there, Jonathan.

. I'll get you back. Right. And moving on to the questions, we have a few questions that have been coming in during the presentation.

Here we go. If a mare has produced an an obitary follicle, is she more likely to produce a similar structure during her next cycles or even in subsequent years? Yeah, I mean, and that's a good question and, and it's, it's difficult to get.

Very firm data on that. As far as I'm aware, there's not been a lot published on that, but without any shadow of doubt, the anecdotal evidence would seem to suggest that the answer to both of those questions can be yes, i.e., if a mayor, mayors are prone.

To forming anovulatory hemorrhagic follicles, even in the absence of using any of the known risk factors, which indeed we talked about them may or may not be risk factors, prostaglandin and so on. Even in the absence of that, certain mares are undoubtedly prone to. Anovulatory follicles.

And unfortunately, there's nothing any of us can do about that. I mean, we make a note in the their record and, you know, we discuss it with, with the owner or with the stud manager, and the stud managers become pretty adept at recognising these, a lot of them, you know. A couple of our big studies call them blood follicles, and they can see these structures quickly.

So you can have a dialogue with them about them, but you do have to make that point that if you have got a mare, which tends to produce anovulatory follicles, she is at an increased risk for doing it, not only at subsequent cycles that season. But it'll even carry through from one season to the next. Apart from being aware of it, difficult to, to know.

It certainly isn't a reason to retire a mayor from breeding, but it's just another feature which I think part of our job is informing the owner of what's going on and being clear with them that yes, hey, I'm Sorry, we're having these problems. It's a form of an ovulation failure. Unfortunately, we can't do anything about it, and data does suggest that if a Mary has one of these ovulations, she's more at risk for having it at the next cycle.

But you can say, doesn't mean she will have, may have a normal cycle, next may have a normal ovulation. So we've got to press on with them, but I just generally alert the mere owner or stub manager to the fact that that can be the case. OK.

Thank you very much, Jonathan. And moving on to the next question, if a mare has a follicular and ovulatory follicle, how often would you ultrasound examine her in order not to waste too much of a client's money? Yes, that's, yeah, again, that's a, that's an interesting issue and, and.

The difficulty, I think, which I have, and I was trying to make the sort of point in the webinar that I know some very experienced colleagues of mine who I've I've worked with on books and papers are more Dogmatic about their ability to diagnose them. So, a a a hemorrhagic follicle, so I guess my point would be. Those the people who felt very confident about diagnosing them, I guess, are going to only have to examine the mare a short number of times.

May may, they may have been monitoring her through the early part of the follicular phase when, as we said, the mares will produce edoema pattern in the uterus, the follicles will look essentially normal at 25, 30, even 35 millimetres, and it begins to go awry. As we proceed into that 48 hour period before ovulation, we get these ecogenic particles appearing. They become more widespread.

The follicle increases in size, and you know, we're thinking, well, this is forming a hemorrhagic follicle, but I think you've got to look. You know, I generally find it's not until I've, I've got a, a, a structure of the size of 78 centimetres, pretty much solid with ecogenic particles, and the edoema pattern has gone from the uterus that I can be sure, well, guys, this may is producing progesterone. We've not had a proper ovulation.

We've got a hemorrhagic and ovulation follicle. She's not going to become pregnant. With better prostag gland in a, in a week's time, then I would put her on the back burner and, and, and, and leave her for 7 days.

But you may take 234 times, or certainly I will to be certain that that may has had a hemorrhagic and ovulatory follicle. And of course, folks, please remember, like I said, be Very, very careful to check both the ovaries out for the not being a normal ovulation, you know, a normal corpus luteum there because multiple ovulation rate is so very common in the mire, and you may well have a cycle where there's a hemorrhagic and ovulatory follicle, but also a perfectly normal. Ovulation with release of the OSite formation of the CL, and clearly if you've bred the mare naturally or artificially, there's a likelihood she's going to be pregnant on that.

So I probably err on the side of examining the mares more frequently than other people might do just because I don't think you can be . 100% dogmatic for, for, for on one examination. It may take you 2, it may take you 3 before you can decide, yes, I'm happy this mayor has had a hemorrhagic anov follicle.

There's no other ovulation occurred. There's no possibility she's pregnant, so we're going to manage her accordingly. OK.

Brilliant, thank you, very comprehensive answer there, Jonathan. We have two more questions, waiting, if you have time to to go through those quickly. Take a couple more, take a couple more.

Let me have a look, here we go. Do mares tend to be predisposed to one type of an ovulatory follicle, HAF or persistent follicles, or are they random events? Yes, at the risk of saying this to every question, that, that actually is another good question.

It's going to test my literature knowledge now and maybe somebody's gonna listen somewhere around the world and tell me there is a written publication about this, but my take would be, there is nothing published about whether a mere. Which, tends to produce the hemorrhagic and ovulatory follicle, the more common type, 85% was our percentage figure, or tends to be the one producing the follicular persistent follicular structure coming in at around 15%. What I'm trying to do is think of, of, of the mares I've examined, and I guess.

My feeling is that the hemorrhagic and ovulatory follicles tend to be more frequently. Seen at at cycles. What I'm not sure I've explained that very well.

If a mare has a hemorrhagic anovulatory follicle or one of the luteal type forms of anovulation failure, I think that is a more repeatable at subsequent cycles. She's more likely to have another one of those. I've not noticed that she's more likely, if she has the the luteal type in one cycle, she'll go onto the follicular type in.

In the other, but I'm not convinced that isn't just because the follicular type is rarer, so I've not got as good a handle on that. And they're also more difficult to get rid of. But I, I'm, I'm thinking back when we had managed to get rid of the.

Persistent follicular type structure which doesn't haemorrhage. They've generally had a normal ovulation at the next cycle. So, that'd be something I might go back and try and look at some data on that, because as far as I'm aware, there isn't a there isn't anything published about that.

But my feeling is with the, the, that the luteal structures, yes, they tend to remain, in subsequent cycles forming that luteal and ovulatory follicle. But the second type, I don't notice them as much forming one of those in the next cycle. Although they're more difficult to get rid of, I think once we have got rid of them.

There's more chance you'll have a normal ovulation, but that would be in my opinion. I wouldn't have any data to back that up. I don't think anyone else has been clever enough to think of that as a, as an issue, so there you go, very good.

Thank you, Jonathan. We like getting our speakers putting their thinking caps on a little bit. So, right, on to the last question we have at the moment, so we'll call this the last one for this session.

If a mare has an ovarectomy of the granulosa cell tumour ovary and the other ovary is left in situ, will the mare start cycling again to allow her to breed? Yes, I mean, that's, it's, it's, that's an interesting point. And my feeling is that it depends how long the mayor has been having the condition of a granulosa cell tumour.

Something which I always, if I, if I am asked to talk specifically about that subject, I, I, I, I feel is a very important point to make is Because I always think it's good to make points that you pick up from your sort of the thousands of rectal exams I've done, rather than what you read in a book. And what never gets written in a book is this impression I have that of course. A granulosa cell tumour has to have a point at which it begins to form a granulosa cell tumour.

If we look at it in books, it's generally, it's at an end stage by then. People write about a case of a mare with a granulosa cell tumour. It's well advanced.

It, it's got elevated inhibit, it may well have elevated. AMH, anti-malarian hormone levels, it may well have, the contralateral, the opposite ovaries become very, very small, really due to being shut down by the inhibit, you know, the inhibit from the tumour ovary stops all the follicular development in the opposite ovary. That's why it is so small.

But of course, If we looked at that may early on, we may just have an incipient formation of the granulosa cell tumour, and in those cases, the other ovary may well cycle and and and and and hasn't in fact even been shut down, and, and we will occasionally have a colleague of mine, James Crabtree's written up a granulosa cell tumour. In pregnant mares, so there's no doubt that the granulosis tumour can develop over a period of time. And if, as we usually see it presented or talked about, it's well advanced and the contralateral ovary is very small and firm with no follicles.

I think it can take 12 to 18 months from removal, before we, we, we see the follicles beginning to grow again. They've been freed from the negative effect of inhibit and, and, and developed as pre-ovulatory structures. So I think you should, what we generally do is that we err on the side with the owner that this could well take 18 months from removal, before we see this mess cycling again.

And if it happens to occur within 12 months, a little bit of a bonus. And I think some people underestimate the amount of time it can take from removing an ovary with a granulosa cell tumour to that mere cycling again. But I would just throw in the caveat that if you, you know, if you're able to diagnose a granulosa cell tumour.

A little bit earlier, not too early, you know, you've got to be sure in your diagnosis, and that's why I think we've got to move off ultrasound diagnosis only. We've got to use these hormone measurements, and that's why I think it's particularly exciting. We've now got in the UK at least, this, this ability to measure AMH, anti-malarian hormone, and give us a very definite diagnosis.

If we get that indicating a granulosis cell tumour. I think you may well be better to remove that ovary as quickly as possible, and I think you then may cut down the time between removal of the ovary and the mesh cycling again on the ovary you've left in. OK?

Excellent, thank you very much, Jonathan, for your time today presenting the webinar and going through the questions so thoroughly as well. Thank you very much. I'd also, again, just like to thank MSD Animal Health.

It's great to be able to provide, so much free CPD. So if you've enjoyed watching this webinar, then, make sure that you inform any colleagues that you think, may, benefit and be interested in this webinar. So, you know, do, do forward that on.

That's it for questions, Jonathan. So, it just leads me to thank you once again and thank you to MSD Animal Health, and, he's looking forward to seeing you all on, another webinar very shortly. Thank you very much, everybody.

Bye for now.