OK, for so for this webinar we're gonna be talking about the diagnosis and treatment of back pain in horses. So back pain in horses, certainly in, in my population, and in a number of others is a frequent complaint, that manifests itself either as poor performance, the horse isn't doing exactly as well as the rider would like it to, or, or indeed as as misbehaviour, and, and probably misbehaviour is, is the more likely in the slightly more amateur subset, of, of our owners, on a more professional scene, it tends to be poor performance. Problem is with back pain is that it is inherently a challenging investigation.

The anatomy is, is very deep within the horse, very difficult to palpate, very difficult to image, and it is essentially a subjective assessment. We don't have a grading system for back pain, and it's often a An assessment rather than an observer assessment. And then undoubtedly in any horse, because it is a behaviour, there is a strong behavioural component to it, and actually teasing out what is behavioural and what is genuinely pain related can be very, very challenging.

Before we actually get into back pain itself, it's worth considering the differential diagnosis list, which is long and very, very extensive. Everyone's aware of gastric ulceration, and certainly we'll see in a moment, you know, a horse affected by that. But other possibilities include ovarian pain.

We occasionally will see horses with dental pain that manifest themselves as ridden discomfort. These cytograms here of a horse that really did look like it was uncomfortable through its back, and the only thing we found was this increased uptake in the interdental region actually resolved once we'd addressed that. Some horses with lameness, particularly bilateral hind limb lameness, will show signs of bucking tension through the back, but, but I actually don't actually have primary back pain.

Myopathy, it is worth considering, looking at pre and post exercise blood analysis for a CK and AST. Some horses with neck pain can mimic back pain, as can pelvic pain. And then sometimes the horse may purely be badly behaved, we'll see as as well.

So it can be very, very difficult to, to truly draw a line between the two. This is a video here of a horse that was presented for back pain. You see it going around on the lunge, it doesn't move beautifully at the moment, but certainly there's nothing particularly wrong with it.

It seems reasonably happy with life. And then the owner's complaint, and quite rightly so, was just simply putting a saddle on, meant that this horse had a marked change in demeanour, tail swishing, bucking, you know, clearly now this is not a comfortable horse, and the only thing that we've done really is put a saddle on and girth it up. And interestingly, this horse had quite an extensive investigation.

The only thing we could find was quite severe gastric ulceration, and this behaviour actually responded completely to course of oral omeprazole. So, unfortunately, the signs of back pain are relatively non-specific, and there are a number of differential diagnoses that almost need to be excluded sometimes before we, end up with, with purely, back pain, which we're comfortable with. I think the history in these cases is very important.

We have a little room at the hospital, and I know that's not always present on a yard situation, but it's definitely worth, even if you're busy and you've got a lot of calls to do, it's definitely worth just certainly when you first see that horse having a chat with the owner, to try and get some sort of handle on what's going on with the horse, particularly as they will often have seen the saddler, the physio, the chiropractor, and, all and sundry before they end up calling us in as a, as a veterinary practitioner. So is this a chronic or acute problem? Is there a likely traumatic cause?

How long has this been going on for? Have they been battling with it for some time, or did it happen just a week ago? Something that you may or may not know is, you know, what type of a horse is this?

You know, what's the temperament of the horse like? Do you know the horse well? Have they just owned it?

And also, perhaps equally as importantly, you know, how competent is, is the owner themselves? Are they very nosy? Do they have, you know, a support network in place of, of people who also agree that the horse is having problems?

You know, a professional owner that says the horse has a painful back is far more likely to be on the money than a, a very novicey owner. In terms of that sort of behavioural versus painful question, I think that can be very, very challenging to ascertain. And it's also quite a difficult conversation to have sometimes to actually suggest to someone that their horse is purely naughty.

I think for me it's highly dependent on the temperament of the horse, and I think you have to look at the horse. Individually and the history as well. So, you know, on the left hand side of this scale, you've got a, you know, 12 year old event horse that's been inventing for 3 or 4 seasons and has never put a foot wrong and is now suddenly bucking its owner off.

You know, that is a horse that is proven to do its job. It's a genuine animal. And I think if they start to then show signs of of discomfort, there probably is something generally wrong.

I think if you compare that with the sort of 5 year old homebred that won't tolerate having a saddle put on and the owner's never been able to get on without being bucked off, I think in those situations, there may be a painful stimulus for that, but unfortunately, there's also a high likelihood that there's a very, very strong behavioural component, and I think that can sometimes be, you know, difficult to establish when the horse is perhaps somewhere in the middle. In terms of trying to establish definitively, an analgesic trial is an option, and we do certainly look at those. Phenybutisone at a reasonable dose of, usually 1 gramme bid for 14 days for an average sized horse is something that the owner can do.

I always tell them to just be as objective as possible, either video the horse or, or make a diary of its behaviour in a hospital setting or, or even under a veterinary supervision. I do occasionally use morphine intramuscularly and phenolbutasone IV and get someone to ride the horse pre and then two hours post that. The problem with all of this is that obviously there is a learned behavioural component to this behaviour.

And often we not, can't, can't completely eradicate that. So, But of course, you know, if you're, if you're trying to fix a horse that's essentially badly behaved, you know, that's slightly outside of veterinary remit, and you're going to find that very, very challenging. So I think getting some honest opinion of, of, of, of that horse's behavioural aspects before you start is is probably a sensible thing to, to do.

Interestingly, there's a very nice study that came out, in 2013, from an Australian group, Buckley AA, and they looked at, risk factors for misbehaviour in a group of pony club, horses. And interestingly, the risk factors were obesity, so the fatter the horse, the more badly behaved it was likely to be lush grass, so spring and summertime. Those horses that were irregularly exercised, and at competition horses were more likely to misbehave, and there was actually no association with back pain or lameness with with misbehaviour, and I think that is probably a pretty realistic study in terms of what we should expect.

You know, this was a horse that was presented to me for back pain, and we got one of our nurses to ride it and effectively this horse. Every time you got on it, all it would do is just rear and just pull you towards the gate, essentially until you, until you got off. And, certainly our sensation was is that at no point was this animal remotely uncomfortable, and it had spent, you know, several months, towing its 14 year old owner around and generally doing what it wanted, so.

You know, obviously the owners were very concerned that this horse was in discomfort and it was very distressing for them. But at the same time, you know, I'm really not sure that there's anything from a veterinary perspective that we could do. And interestingly, we got a professional trainer involved with this horse, and actually, she went fine after that.

In terms of assessing these horses, visual assessment, I think is important. Looking for, particularly for asymmetry, obviously, that requires a degree of chronicity for muscle asymmetry to an atrophy to to have kicked in. But certainly if we stand back and actually look at these horses, they will often show areas of poor muscling where they have issues, particularly in the thoracallumbar region, as compared perhaps to the cervical region or pelvic region.

They may have left right asymmetry which may give you a clue as to, whether or not there is, a degree of, of lameness or musculoskeletal compromise there. How are they put together confirmation if we look at this picture on the top right, this is a horse that's got the classic sort of straight hock with long pasttern and a hyperextended fetlock confirmation, which, you know, as we know, predisposes these horses to suspensory pain. And again, it may just give you a clue as to additional orthopaedics issues that may be going on.

Something that can be quite difficult to assess can be tack fit. I do like to see the tack in place. I'm by no means a saddler, but if there's anything that seems particularly awry with regards to tack fit, you can at least perhaps, you know, get an opinion from another saddler, or if the tack hasn't been checked recently, then certainly the saddle should get involved as well and make sure that all of that is, is optimal.

Palpation, the horse, I think some of these horses can be very anxious, with regards to palpating their back. Now, that can also give you clues as to the type of horse that they are. But the use of acepromazine, I think, can be, can be useful to facilitate your clinical examination.

Some of these horses get to you in a situation where even if you move to examine them cordial to the withers, they'll start trying, trying to kick you. So clearly at that stage, their behavioural response is, is highly disproportionate to the degree of pain that they, they have. .

I think everyone will have their own, way of evaluating, the back, but I tend to start in the dorsal midline. And whenever I'm palpating the back, I tend to start fairly gently, and then I just sort of go back over that same area slightly harder, and then increase the pressure, rather than just going in and sort of, and pressing hard for the first time. And then we move laterally to look at the apaxial muscles as well in terms of tension, focal pain or palpation.

And then obviously try and assess range of motion, using a pen or key or a sort of firm object like that, which we'll see, door sally, ventrally, and laterally. And I think the thing, sometimes very subtle changes can be, can, can be genuine, and I think the thing to be aware of as well is that obviously a normal horse will actually have quite a nice supple, flexible response to range of motion testing as well. So, If we look at this polar pony, here, we move gently down the dorsal midline, and this is a slightly shortened exam, but I would go backwards and forwards.

Moving over that, if you do find a painful area, go back and check that it's a genuine pain response. And then finally, you check our tubers of crali as well, although obviously we're moving back into the pelvic region at that stage. And other bony landmarks.

If we take a firm object and run down the appaxial muscles, a normal horse should have a really nice, supple flexion away from that. That's an involuntary flexion response. And owners sometimes get quite, anxious if the horse really dips or ducks away.

That, but obviously that's the indication that they are comfortable. If you look at this horse, she's actually very tight and boarded through her back. She should be doing a far better job, particularly, I'll just play that again, a far better job of, certainly dorsiflexion here, so.

Where we flexor impacts your muscles, we'll see in a minute that she has a slightly asymmetric lateral flexion response. She, she flexes better to one side. And then horses that don't have a painful back when you actually flex, you, you know, stimulate them ventrally, should really arch their back up.

And, and you can see that this horse here is boarded. She doesn't really want to arch up through her back at all. And then finally, when you run down over the back, the normal horse again should, should really be comfortable arching, arching up.

If we look from the back, and again these are sometimes quite subtle responses, you can see here that she has a very asymmetric response. And she's quite happily flexing towards me when I stimulate the left hand side, but then she's very uncomfortable and this horse had injured, it's back in a ride off and had an asymmetric lesion. So, so sometimes, again, you need to check left right asymmetry and go back over things, obviously in, in a slightly bigger, thicker draught breed type horse.

This is a little bit more difficult to, to appreciate. Gait analysis, I think it's important. I, I look at these horses that walk in the trot in a straight line, and I really, you know, even for horses that are, are referred in to me for, for back pain, for the treatment of back pain, I would always do a full, lameness assessment with them.

It's amazing the number of horses that are ostensibly sound when they're, they're sent in with back pain, that actually genuinely do have some underlying lameness problems. Now, they may or may not be significant, but we should at least be aware of them. I see these horses on the lunge, ideally on a firm surface and a soft surface, and I think it's really important to canter them as well.

You can learn a lot from how they move through their back at the canter, but also, as we know, there are plenty of forms of, bilateral hind limb lameness that don't really manifest themselves at trot, but obviously do show up at the canter. I tend not to routinely fle horses, but obviously that, that may be appropriate. And the reason we do that is that you know, some of these horses with back pain do have genuinely significant hind limb lameness.

This is a horse with bilateral. Suspensory degeneration, actually, more worse in the right hind than the left, but when you block his suspensory out in the right, he switches to quite a marked left hind and lameness. And the owner was convinced that the reason he didn't want to be ridden was because he had a painful back, and yet actually, I, I think this horse had a chronic, degenerative suspensory disease, and that is why he was telling the rider he didn't want them to, to get on.

So, you know, I, I think if we overlook lameness. Potentially we sometimes miss quite important bits of the puzzle, and certainly we know that there are some back conditions such as dorsal spinous process impingement that are much more difficult to get under control if you have concurrents as well, las as well. So, don't overlook that.

Having said that, you know, we document the lameness and sometimes it's a relatively limited significance. So just because a horse is mildly right hind and lame doesn't mean that that necessarily is, is the cause of its back pain. I think written assessment, we obviously need to be careful with these cases because there are, safety assessment, you know, safety implications for, for all of, our, our, our, our owners, but particularly when there are minors involved, when there are underage rises involved.

So, you know, I tend to look at these horses, with the saddle on only initially, as we saw from that, Appaloosa on, on the second slide, sometimes just applying the saddle would provoke a reaction. There is now a dummy ridle rider that's been formulated that, you know, stimulates the stimulates the weight of the rider, which, which is a nice thing to do. Having said that, I think if you can safely do it and the owner is willing to, you can learn an awful lot from from written assessment, just by looking at the demeanour of the horse.

Are they comfortable in their work? How is their gait? Some horses will show the development of lameness or an abnormally just restricted gait.

And then are they actually showing aversive behaviour in terms of, rearing, napping, bucking, whatever it may be. And, and I think to try and get some sort of, some degree of objectivity into this, I normally try and, you know, quantify that behaviour, either by, videoing it or by, recording how often the horse, behaves that way, so that you get some way of knowing, particularly if you're then going to perform regional anaesthesia, whether you've made that horse better or not. If we look at diagnostic imaging of the back, we essentially would commonly think about radiography, ultrasonography and nucleus intigraphy.

Thermography is available, but certainly I have limited experience of that, and it's, you know, not something in my hands, that's been a particularly useful technique, so I'll concentrate on, on those three. Radiography very widely available to all of us. There are, however, anatomical limitations as to what we can actually radiograph, and it's worth communicating that to the client.

We know we can look at the dorsal spinous processes we're most of us are lucky to have, reasonable quality DR systems now. I think it's worth, being aware that, you know, even with a good quality on the road system, we still probably won't get the same. Quality of image and the penetration of of tissue that we will with a hospital-based gantry system.

So, you know, that is worth considering that you, you might be able to get better images in a hospital-based scenario. But certainly, we should be able to acquire radiographs of the dorsal spinous processes, the thoracic vertebrae, the articular process joints, particularly in the thoracic region as well, and also the ribs. We do so with basically two projections, effectively, the lateral lateral projection, but we vary our exposure and our area of centering for both the dorsal spines processes and the thoracic vertebrae.

In a finer horse or a smaller horse, you will be able to get the lumbar vertebrae as well, but it's difficult, because we don't have the, the, the gas filled, thorax to act as a nice, a, a nice contrast for us. And then to acquire images of the facet joints and the ribs, we use an upwards 30 degree oblique projection, with the plate, perpendicular to the, to the beam and and laid alongside the horse, and the only variation between those two tends to be the, the point of centering, as to whether or not you wish to have the, the ribs or the facet joints. In doing so, You know, as we can see from this reconstructed, lateral radiograph, we can get very nice quality radiographs, certainly of some important parts of the horse's back.

But as we know, particularly from the cervical spine and the use of, computed tomography there now, you know, radiography is essentially a 2D projection of a very, complex 3D structure. And therefore, the limitations of radiography have to be accepted. And we do sometimes get presented with horses like this in the top right, you know, for, for back pain, really, you know, imaging him, he's going to be a very, very challenging thing, and, and sometimes we just have to accept that we don't have the exposures, to actually get through as much tissue as we would like.

Things to remember, we obviously have a duty of care to our staff, ourselves, and also, the owner as well. We need to have adequate radiation protection equipment. We are using high exposures here, and the beams are often pointing, you know, horizontally or sometimes even upwards into the room, creating a lot of scatter.

So as a minimum, people need to be wearing, appropriate PPE lead gowns, thyroid protectors. Usually, sometimes people are holding the plates, in which case they definitely need to be having lead gloves on, preferably is to have an actual plate holder that puts, personnel away from, from the primary beam. And we need to make sure we have adequate radiography equipment as well, because, and, and if your, the equipment that you have out on the road is not sufficient, then, you know, it's worth just acknowledging that and, and accepting that the horse may need to go to somewhere for for better quality radiographs to be, acquired.

And as always, you know, the significance of any radiographic changes has to be carefully assessed as well, and we'll see in a moment when we look at some specific conditions. We know that there are a number of, you know, radiographic changes that can exist in clinically normal horses, and we need to be careful that we don't interpret overinterpret them, which is certainly a a limitation of, of radiography. Oceanography, underused generally everywhere in practise, and I think the same is true within the back.

It is safe, it's cheap, and it's easy to perform. One problem is, is I guess it does require a decent scanner. You certainly need a curvilinear probe, to, to perform it.

You can't really image anything other than a supraspinous ligament, with a linear probe. So you do need a curvilinear probe and some operator experience is required. Well, that, that's the problem with the ultrasound in general.

Having said that, you don't get experience without just trying it. So I would urge people to, you know, try scanning backs and just getting an idea of what is normal, so that when the abnormal horse comes along, you can more easily pick it up. In terms of soft tissues that we can see, obviously the supraspinous ligaments, we, we can image very, very nicely, just with a simple basic linear probe.

And then we can also pick up the other soft tissues, the mitous muscle, longissimus dorsi muscle, for example. Ultra ultranography is the imaging modality of choice for the articular process joints, particularly in the lumbar spine, where they're very difficult to see radiographically. And actually, as we'll see later on as well, they provide a very nice way of imaging other areas of the spine, such as the transverse processes, and also the, the ribs, ultraso per rectum is also able to access, limited parts of the ventral aspect of the caudal lumbar spine as well.

And finally, nuclear centigraphy, is widely used for back pain and certainly perhaps, you know, horses are referred to us for centigraphy when they have back pain more commonly than perhaps they are just for hind limb lameness. There are obviously downsides to nuclear centigraphy is it's expensive, so it's a large chunk of your insurance money gone, in a single imaging modality, or even more so in an uninsured animal. You know, obviously, we know that it has, you know, it is good for bony lesions, but it will not clearly pick up some primary soft tissue pathology.

Again, we need to be aware that just because there is increased rate of pharmaceutical uptake and region does not mean that it's necessarily significant, and owners sometimes find that very difficult to, to, to, to get that, and, and they think just because the area is hot, it clearly has to be. Significant standard views that we would acquire would be lateral projections, from, from both the left and the right. That's always quite a nice way of actually seeing how, you know, how, how hot any increased uptake in the dorsal spine processes is relative to the vertebra vertebrae, dorsal ventral projection.

And I particularly like the oblique projections as well, which are, are better, I think, for looking at a, the facets, and B, actually looking at more subtle increased rate of pharmaceutical uptake within the, the dorsal spinous processes. And then we would obviously scan, the rib cage, depending on, the, the need for that. Diagnostic analgesia, as with Lani, really, I think he's the gold standard for assessing the significance of a lesion, and I think bearing in mind that we, we know that there are plenty of lesions that can occur in clinically normal horses, I think it is, essential for some conditions.

But we know that there are bits of the back that we can't access with diagnostic analgesia, and, it's mainly used for dorsal spinous process impingement. I'd like to do that under radiographic guidance if possible, usually with short-acting xylozine sedation. My personal preference is to, put in two needles, each about 1 centimetre or so to the right and left of midline.

I, I worry with a very sort of, impinging back that if you stick in the midline, you're not going to be able to direct your needle, right down far enough to the sort of most ventral area of impingement. So I tend to come, to the right and left of midline, almost triangulate across, and then push a sort of 19 game. 2 inch needle or even a spinal needle in a very large horse down and inject a total of sort of 6 mil of mepivacaine per space and normally 3 mil per side, and then ride the horse 45 minutes later, to see if it had significant improvement.

If we look at some specific conditions now, if we start with dorsal spines perrosis impingement, kissing spines, which certainly seems to be the one that most owners are, are aware of. You know, we know it is a very common radiographic finding. There's a very nice paper which is 15 years old now by Eriksson Eal, in the Eine vette Journal, and they looked at a population of riding horses that had absolutely no clinical signs or back problems, so they weren't painful through their back.

They were getting on with their normal, daily jobs, absolutely fine. And then about a quarter of those horses, they had no radiographic or scintigraphic changes, but it was only a quarter of them, and the rest of them, did have some uptake at scintigraphy, or some radiographic evidence of, dorsal spinous andros impingement. You know, and, and that really has, has sort of stood the test of time and that we are now aware that, you know, there are some horses that have radiographic or syntographic changes and are clinically significant.

Having said that, you know, when they actually looked at the severity of those changes, they were generally mild. So, you know, the more severe changes tend to be associated with an increase likely to have been clinically significant. Certainly this has pre-purchase implications as well, and, and as I said, one needs to be careful as to how we interpret radiographic changes in clinically normal horses.

If we look at the dorsal spinus process impingement, we know that thoroughbreds are overrepresented, and it tends to happen in the sort of mid to caudal thoracic region. In various papers, it's been documented in the sort of T14 to 17 region. Generally, it tends to, it's very rare that it occurs more cranial than T11 12, or rather, you do sometimes get it in the mid lumbar region, it tends to be less clinically significant in that area.

You know, it is readily identified, but when are those changes significant? I think that's when diagnostic anaesthesia plays its part. Zimmerman, ETA in 2012, they looked at the relationship between radiographic findings and syntographic findings and clinical signs.

And essentially the upshot of that was there was a reasonable correlation between the two, actually, that radiography and syntography had had reasonably good correlation. And generally, the more significant those imaging. Findings were or the more severe the imaging findings were, the more likely they were to be tied in with the clinical signs.

So, you know, if you've got a very advanced back on radiography and sintigraphy, it is more likely, shall we say, to be causing a clinical problem than the one that only has mild changes. But again, you know, if we can confirm that with regional anaesthesia, that just makes everyone a little bit more comfortable before we move forward with, with treatment. If we look at treatment, many of these horses will respond to medical management.

I think, you know, there are plenty of horses that will present with dorsal spinous process, impingement and pain that have had particularly maybe a period of time off, for some reason, they may have additional issues, and I think it's important, particularly for DSP lesions that we do address any underlying lameness, get this horse as sound as we can. If we look at systemic medication, these horses can work on anti-inflammatory medication, Acipromazine if they're particularly anxious. And then, under radiographic guidance, we would then, ideally medicate those sites of impingement.

I use a similar technique to medicate the backs I do to to block it. My usual choice would be methyl prednisolone. The only implication of that, of course, is that beware that it has, you know, quite a long withdrawal time and certainly in competitive animals, you know, there have been positive tests, at to, you know, sometimes even 3 months post injections.

So, you know, an event horse mid-season, you know, that really is not ideal. And, and, something like Triamcinolone will give you a shorter, you know, shorter time before you can compete again. And then some people will use other things like Sarapin as well for that very reason.

. I think physiotherapy has a role to play in these horses as well, both manipulation, but passive stretches as well. There's a really nice paper by Stubbs EA in 2011, that basically put horses on a programme of carrot stretches, two or three times daily, and they ultrasound scanned the back and they documented a significant, a clinically significant, and certainly, objectively significant increase in multifidous muscle. Or diameter over a 2 to 3 month period.

And obviously, what we're trying to do, generally, when we medicate these horses is improve, core strength, improve, muscular stability so that when the medication wears off, they're able to, continue, and support that back. Because what many of these horses, if they have a painful back, they will lose, muscular tone, and then ultimately, they're less able to cope with the pathology that they have. And I tend to do that from the ground initially.

If, if, if I am treating these horses medically, I'll put them on a programme of, you know, 4 to 6 weeks of, of groundwork, lunging exercise, using aids such as a uroa and the like to try and build up, build up muscular strength before I get the rider back on again. There are a number of adjunctive therapies as well, such as mesotherapy, acupuncture, which have their place, but obviously have, unfortunately somewhat limited evidence-based medicine behind them, and, and obviously we need to be aware of that. If Medical therapy fails, or if we have, a case that looks just so severe that, you know, we might want perhaps to move past medical therapy, then, then surgery, is, is an option.

Certainly, in our clinic, it's now routinely, performed as a standing surgery. I can't remember the last one I did it under general anaesthesia. And even horses with very, very painful backs usually tolerate this surgery very, very well once you've got them, sedated and, Local anaesthetic in place.

Various techniques have been described. There's a complete ostectomy, which is my personal preference for severely impinging processes. There has been a subtotal ostectomy described, which one takes out a cranial wedge.

And then finally, the interspinous ligament desmotomy has been described as well in a in a single paper by Richard Coomer and colleagues, Richard Coomer and colleagues some years ago now. The interspinous ligament dismotomy is, is very popular with owners, and, and certainly has the benefit of smaller incisions and a quicker rehabilitation time. My only problem with that is certainly in the population of, of courses with dorsal spinous process impingement that I see, you know, the majority of 77, the majority of them tend to have such a high degree of impingement that one physically can't get a, a pair of scissors down between the processes and therefore, an ostectomy is the only option you have.

And depending on the paper that you look at, you know, a high success rate has been reported, between 72 and 95%. And, and these horses do make excellent surgical candidates. I think for me, the only time that they don't respond well is if that they're, you know, if they generally don't have DSP impingement, and either they have significant behaviour issues, you know, or they may have additional, lameness issues as well.

And I think those make, those cases respond more poorly to surgical therapy. If we move on to facet arthropathy, we see here, a cranial view of the facets here. We've got the dorsal spinous process, and then moving out, we see the slightly oblique facet joints, with the mammillary process.

And when we assess these ultrasonographically, we get this characteristic picture that's always been described as a, as a chair. So we have the vertical. Dorsal spinous process, which is the back of the chair, the seat of the chair is actually created by the the, the facet joint itself, and you can normally see a little sort of notch in the middle of the horizontal part, which usually is the joint, and then we have the drop down onto the, the transverse process.

And for me in particular, ultrasography, as we said, is the imaging modality of choice for assessing these, particularly in the sort of cadal thoracic, but also in the lumbar region where we just can't really radiograph them as effectively as we would like. Radiographically, we do a ventro dorsal projection at about 30 degrees, and this is the kind of view that we'll get and we can see the facet joints here running bleakly . And We can assess them back.

We see the diaphragm coming in, and once the diaphragm starts to to get involved and the the abdominal cavity starts to get involved, we obviously lose definition. We're not able to image them as effectively, certainly in most large animals or those that are obese, and a certain size. In terms of facet arthropathy, that would be the most commonly described.

Osteoarthritic changes are the same for the facet joints as, as any other joint, to be honest. We see sclerosis, around the articular margins. Osteophyte formation, narrowing of the joint itself, and, and this has been documented at slightly further cordially than the classic site site for dorsal spinous process impingement.

So it's normally in sort of cordal thoracic, but early lumbar region. For me personally, I tend to see a lot of facet arthropathy extend back in sort of L34, but, but doesn't really go further back than that. Obviously, how we detect these changes depends on the imaging modality, certainly osteophyte formation and, periodicular modelling is better assessed ultrasonographically, normally.

It has been documented as well, particularly in thoroughbreds, that, you know, we may see facet arthropathy in conjunction with dorsal spinous process impingement. The theory being is that 1 may prestide the other, and we don't entirely understand the relationship between the two. As always though, you know, the question is, what is the significance of those changes and one needs to be careful.

There are a couple of papers a few years ago now that looked at syngraphic assessment of the thoraclumbar synovial into vertebral articulations, the facet joints, that was Gillanettal again. Documenting that the oblique view is very nice additional view for for documenting that. And again, in general, you know, increased rate of pharmaceutical uptake, the more severe the increased rates of pharmaceutical uptake, the more likely those changes were to be clinically significant.

But they did make the point that, you know, a number of horses had increased uptake, and they were clinically normal. Probably, in, in that respect, Jura drew, Eal in the same year, they looked to osteoarthritis of the thorac lumbar facet joints, and they looked at the clin, they tied that in with clinical signs and 77 horses with poor performance and back pain. And ultimately, again, just as there were with dorsal spinous process changes, you know, the more severe the imaging findings, the more perhaps likely they were to be associated with clinical back pain, you know, essentially the take home message was is that there are, you know, some horses do have abnormal .

For arthropathy, and yet can be clinically normal, and we need to be very difficult and very carefully in terms of how we assess and quantify those changes. And unfortunately, it often comes down to, you, you know, we sometimes just medicate those horses and see how they respond to, to medication. I think this is a slide I always like to put up because it's probably one of the most severe.

A really nice ultrasound scan of a really marked for set arthropathy bilateral here at T18L1. If we remember what this should look like, we should have the nice spine and then the flat chair and then drop down, which clearly we have marked periarticular modelling, and you actually see that we've got the that ties in with The increased marched radiographic increased uptake on centigraphy. But this horse was actually clinically asymptomatic, hadn't had a day's back pain in its life as far as the owner is aware, and she'd owned it for 5 years.

So, you know, one has to be very, very careful as to how we interpret this pathology. In terms of treatments, very similar to, dorsal spinous process and impingement, in terms of medical assessment, we have to address additional pathology, be that dorsal spinous process pathology or hind li lameness. And then the mainstay of treatment will be intra-articular medication under ultrasound guidance.

And we can see in this ultrasound image here, the needle, is coming down nicely within the two dotted lines. Many ultrasound machines now will have a biopsy guide, and you can buy a biopsy guide which clips onto your curve your probe. And ultimately, as long as the target areas within that, those two dotted lines, where you stick your needle is likely to be where, where it ends up, which I find very, very useful.

And then in conjunction, once we've medicated these horses, and hopefully made them more comfortable, we can implement, similar, additional, options such as physiotherapy to try and build up, core strength and improve mobility just as one would with an arthritic joint or any other. Site. The issue with that, though, of course, is that unfortunately there is very little evidence-based medicine as to outcome and prognosis, and unfortunately response to medication tends to be the best predictor of how these horses are going to do in the, in the medium to long term.

And certainly we have several horses that respond very nicely to medication, and they go away, they compete for however long it may be, and then they come back and they're, they're re-medicated. Spondylosis is uncommon. Lucy Meehan, published a series, I think, 640 horses, with, that had full survey back radiographs, and spondylosis occurred in about 3.4% of them.

So a very low incidence. It's usually. In sort of T11 to 13 region, and normally one, more than one side's affected.

You can see this is a fairly classic radiograph here where we've got bridging mineralized tissue on the ventral aspect of two invertebral spaces. Sentigra is actually poorly sensitive for this, and even quite marked spondylosis tends not to show up brilliantly well on bone scan. You know, the difficulty, of course, is, is what is the significance of this.

Sometimes it's found in isolation. But more often than not, there are additional, pathologies there which, need to be, addressed. There is obviously nothing specific that one can do for spondylosis per se.

Spinus ligament desmitis, as we said, the supraspinous ligament is very superficial. It can be readily assessed with ultrasonography, with a, with a linear probe. Because it's so superficial, we do actually see, you know, classic signs of desmopathy.

We see heat, swelling and pain. I think because it's superficial, it is very sensitive to things like poorly fitting tack and direct trauma. So, you know, tack assessment is key when you're looking at horses that have or have suspected supraspinous ligament de mitis.

Ultrasound is useful for assessing the ligament, but with the one significant caveat in that there was a very nice paper back in 2007 by Fran Henson out of Cambridge, and she looked at ultrasound scanning in a group of horses, three groups of horses, actually, a group of horses that had never been ridden. A group of horses that were ridden but clinically normal, and then a group of horses that had other back pain. And essentially they found that pretty much all horses, or the majority of horses have some degree of, of, of ultrasound abnormality within the supraspinous ligament.

And there are two portions. We see the long portion of the ligament which runs right over the top, and then the little branches that come off and insert onto the cranial aspect of each, dorsal spinus process. But unfortunately, there was no significant difference in sort of ridden and unridden and then horses with back pain as well.

So, you know, you may find in horses with raspinous ligament de mitis that you do get enlargement, loss of fibre alignment, and, and so on and so forth, but just be aware that in a population of normal horses, they can also have, pathology or, or certainly, ultrasound changes as well, and we need to be careful over and. Rib fracture, rib fractures are reportedly described as a cause of back pain, actually. We reported these, as far as I'm aware, for the first time actually in 2016 as a beaver abstract, and that paper's just being produced for publication.

Suzie Hall presented it at Beaver. At that time, we had 18 cases, we've had a few more, since then. And these horses do present with, with back pain, essentially, and interestingly, there are very few localising signs, so even knowing where the rib fracture is, if you go back and palpate these horses in that area, they often won't, won't show any focal localising signs.

Tends to be the caudal ribs are overrepresented, particularly the 18th rib, and I guess that might be, more vulnerable to trauma, if these horses slip or fall. They are readily identified with centigraphy. I guess the concern with that, of course, is, is, is knowing how, how clinically significant they are.

You can desensitise these, these with horses with, with local infiltration of local anaesthetic, but, it, it, they, they're sometimes quite deep, and we tend not to, to do that now. Most of them do respond very well to conservative therapy, so 3 months in the field, and the majority of these, will go back to their previous level of athletic performance. You do get the odd one.

That seems to be left with an unstable, callous or or ongoing pain from that. From an imaging perspective, you can take an upward oblique view. You can see on the right here, we see a little callus associated with the rib.

They tend to happen about sort of 10 to 15 centimetres lateral to the cost of vertebral articulation. Ultrasonography is is far more sensitive for the detection of these than than radio. Yours, you can see here if we compare the left and the right, ribs, on the left, we've got an obvious fracture with a callus forming.

And that's nice for the detection of these. I find it far less useful in terms of monitoring these because the callus will stay there for some significant period of time, and, and, actually, usually a period of rest, and then, starting these horses back up and then be sufficient. Vertebral fractures, we don't see, that many of these, and these can be catastrophic, tend to occur either through blunt trauma, but they can have a stress fracture aetiology, just the same as, pelvic fractures, particularly in racing animals.

This has been described, in some nice. Postmortem studies in the late 90s by Sue Stover and Kevin Hausler, and they often seem to be associated with maladaptive change. So, and, and often, often they do have some association with pathology further cranily.

So they tend to happen at the sort of caudal lumbar regions, so. 56. But often these horses will have pathology, sometimes quite significant pathology for the cranially dorsal spinous process impingement, fort arthropathy, and therefore, one wonders if they are perhaps, you know, using their back abnormally.

And the theory being is that just like, other bony tissues in the body. We they undergo a maladaptive response to the physiological loads of, of training, and then ultimately, they can, fail under, usually under high speed when racing or, or training, that present either with severe back pain or sometimes with neurological signs, depending on, the degree of, compromise with the spinal cord. Soft tissue pain, soft tissue pain is a very nebulous thing.

I sometimes one does find horses that have genuinely painful backs, but you look for all other pathologies and, and can't find them. I think in those situations, one does look for an underlying cause, really look very closely at these horses and make sure they don't have any underlying hind limb lameness, particularly bilateral hind limb lameness, and do look for a primary back lesion. But ultimately, if we can't find those, then we have to try and treat these horses appropriately and You know, the reason I've put a question mark after treatment is there's a whole host of options that are available, well, unfortunately a very scant evidence base as to their efficacy.

We know the shock wave is analgesic, so, you know, that's a nice way of keeping these horses going. Acupuncture can be widely used and certainly can help many of these horses. The options include physiotherapy, things like me therapy and the like.

So, you know, there are a number of options available and everyone will have their preferences depending on what they've used. But of course, one has to, you know, inform owners that unfortunately the evidence base is relatively scant for that and and really it's a question of trying these things and seeing how one gets on with the horse. So thank you for your attention.

I hope that's been helpful, and, that ends this webinar on the managed diagnosis and treatment of back pain.