So tonight we're going to have a, sort of a little bit of a discussion about identifying that surgical colic case at an early stage. So I think many of you will realise why this is important, but I think it's always important when we make such a broad statement such as this. The early referral and surgical intervention of horses remains one of the most significant factors in maximising horse's chance of survival following colic surgery, that you actually think about the evidence that there is to back this.
And a number of colic survival studies have been done over the years, some of them at Liverpool, performed by colleagues, and others done elsewhere. But one of the consistent features that, has been found between studies is factors such as horses' heart rates and packed cell volume. So you can see in this graph here, so the chances of horses dying increases, and the greater the horse's heart rate is on presentation.
And also you can see from your sort of your normal values of pack cell volume, obviously you've got increased risk with very abnormal values as well, but you can see a pretty linear increase in risk of death with that increase in pack cell volume. Also, you can see from this graph here that the longer a horse with the surgical lesion waits, to have surgery, then again, there is a linear increase in the risk of them dying. Few little misconceptions that are also out there as well.
If you look at this, graph here, you can see that actually age, for example, doesn't really have much of an effect, up until the, the geriatric, sort of ages, and really once you're getting up into the high, sort of twenties. So these are all important factors to consider, but, the fact is that performing surgery in a horse that has more normal cardiovascular parameters on, presentation and at the time of going to surgery is going to maximise the horse's chance of survival, not just in the short term, but also, in the longer term, you know, years beyond that. We know from other studies that have been performed as well that one of the other factors that has implications for short and long-term survival is where the horses have a anastomosis performed and the type of anastomosis.
So I'm sure many of you will be aware of the fact that Ginocecal anastomosis, several studies have shown that they have a poorer chance of survival. So this is a Captain Mayer plot that you can see here. So at the left of this graph all the horses are alive, and as you go along, you can see the days is on the bottom axis.
So we were at 1000 days here. You can see that horses that have a Gigino scal anastomosis have a greater chance of survival than Gigino sorry, Giginoinal anastomoses have a greater chance of survival than Gigino sequel anastomoses. And when you consider performing an anastomosis compared to not performing one at all, then the chances of survival are better if you don't have to perform an anastomosis.
And obviously, things like adhesions, etc. You know, there is a, a risk of adhesions forming here. So I guess my take home message is really, we're trying to get horses to surgery at a stage where their gut is like this.
Both of these horses pictured are epipoic frame and entrapments that had similar quantities of gut and trapped. The horse on the left has minimal serosal haemorrhage, minimal edoema, whereas the horse on the right very clearly, has very devitalized small intestine that quite clearly needs a resection. And this horse is going to have a very poor chance of survival, er following surgery, because obviously the horse has taken longer to get to theatre and surgical intervention.
So we're trying to push the boundaries forward and get these horses to surgery as soon as we can. So those of you based in practise will know, that obviously, not all colic cases that you will see in the general equine population will require surgery. And it's pretty well known that around about 1 in 10, colics seen in first opinion practise will be surgical, and the rest of them will be generally medical, either spontaneously resolving or resolving with medical, analgesic or fluid therapy.
So I think the challenge for the veterinary surgeon in practise, who is the person that we're relying on, and we're waiting for these potential surgical cases to come in. Is that ability for vets out in the field who don't have the luxury of clinic facilities and all bits of equipment that we might have to identify that 1 in approximately 1 in 10 of those colic cases that might require surgery. And of course remembering that for some clients, surgery is not an option or something they want to pursue.
And in those cases, we may need to consider euthanasia. And as I'm sure many of you appreciate, one of the challenges, within equine practise is trying to work out what's going on in the abdomen, and if only it were quite as simple as this. And I think one of the take-home messages from this webinar is that you do not need to make a specific diagnosis.
You really need to identify those more severe colic cases where surgical intervention might be something that's required. Another thing to remember is that common things are common, but I was always told if you hear the sound of horses' hooves to expect a horse, but don't forget that sometimes a zebra might appear around the corner. So just when you think you might have an idea of what's going on with your colic case, there'll always be one horse, or potentially a zebra, I suppose, that hasn't read the textbooks and will throw in something completely unexpected.
So another take home message I think is to keep an open mind, you know, no matter whether you think something is, you're fairly certain about, and particularly if horses don't respond in the way that you would expect, particularly if you're managing them medically initially. So the colic case, I think, is something to think about akin to a jigsaw puzzle, and some colic cases will be maybe a two-part jigsaw puzzle where you've got a horse with obvious colic signs and severe pain, uncontrollable pain, where it's quite clear that you might have something surgical. For other colic cases, you're putting together a large number of factors including epidemiological factors, which we'll run through shortly.
Findings on clinical examination and the results of further tests. And when you put that jigsaw puzzle together, for example, findings on history, clinical examination, rectal examination, all point to a horse with a very obvious pelvic flexure impaction, then you may get those cases where the jigsaw fits together really nicely and it's quite obvious what you need to do and all hopefully goes well. However, some of our colic cases, for example, fos, very small ponies where you might not be able to perform all the tests, or where facilities and dictate that you can't perform, for example, rectal examinations safely or where the horse is non-compliant.
There may be some jigsaw puzzles where you can't quite get all the pieces, but you probably get enough information together to get a general idea of what's going on. And then there are those jigsaw pieces of those jigsaw puzzles with those colic cases where you have a rough idea of what might be going on, but one of the tests or factors, from the history, whatever, doesn't quite seem to fit. And that always opens an element of, not being quite sure what's going on.
So if you think about the colic case as a jigsaw puzzle, I think it's always a good way to start and just remembering that you might not have all those pieces, and some colic cases will be a little bit more challenging than others. The other factor that I think is really important, and obviously, giving a veterinary perspective on things, it's very easy to tell you about the process of working up a colic case and identifying that surgical colic case. But you've got to remember that you've got a horse owner or owners, horse carers who you have to consider.
And typically, it's not uncommon that you might have a horse owner that is mid-flight on their way to their holiday, you can't get hold of them. So you sometimes have additional challenges when you're having to make a fairly rapid, decision on what to do with a horse with, severe colic. And I think it would be fair to say that colic is something that most horse owners dread.
They're aware that it can potentially be fatal, and it usually is something that causes alarm in most horse owners. So when you mention the word surgery, you've also got to consider that a horse owner may or may not have had experience of a horse undergoing surgery and may have some ideas about whether they would want their horse to undergo surgery or not, and perhaps some misconceptions about what surgery involves. Other owners also have concerns, quite rightly, about the costs, the duration of aftercare, and even fairly simple things such as rather than being worried about always having to have 30 ft small intestine removed and being very sick.
How they're going to manage a horse that might need box rest for a period of several weeks. So it's important to think of the owner or the owners or the carers where a horse is on loan, or where you've got a sports horse where there are various connections and co-owners, that it can be quite a challenge, particularly when you've got a horse where a decision needs to be made quite quickly. And owners may be influenced by things that they've heard, previous personal experiences of other horses with colics, and as you'll be aware, there's usually somebody on the yard who will have an opinion one way or the other as to what they should do.
So some horse owners may have a very positive experience, and, may have a surprising, outcome of those, may be worried that a horse, might not be able to fulfil its, athletic, capability. So I think it's very important that horse owners do know that, obviously it's not going to turn your, average carb into a horse that's going to compete around badminton. But there's no reason, you know, if there are no significant complications why that horse can't return to function.
And as you'll see from the picture shown, Desert orchid is a very famous example of this, a horse that successfully returned to very high level competition, having had a quite extensive small intestinal reception. So those are the the good news stories and some of those perceptions that when you talk to owners, you realise that actually they've got very poor idea of what colic surgery involves and what the outcome might be. But on the flip side, you also have to remember thinking about our survival curve, that there are some horses who aren't going to make it.
So for a hospitals such as ourselves, we would normally say to owners that around 70% of horses that come into the hospital with colic, bearing in mind we do get a large number of quite sick colics, about 70% will make it out of the hospital live. And for those horses that we recover following surgery, our survival rates are about 80% short-term survival. That also means the flip side in that horse owners do need to be made aware that there are those 20 to 30% of horses that aren't going to make it and may develop complications some months and possibly years down the line, such as horses with development of adhesions.
So I think it is important and it's certainly something we deal with quite quickly when we've got to make a decision, but making sure that owners are fully apprised of what colic surgery involves, because some people have quite a negative perception unnecessarily, and other people genuinely aren't aware of what costs, etc. That colic surgery involves. I'm not going to spend a lot of time talking through the in-depth details of, of working through a colic case, because I'm sure that many of you will be used to assessing these cases, but just picking out some key features that you do need to think about.
So the first thing is taking a history. Obviously, if you've got a violently painful horse, that may be a fairly short history, with a more complex, maybe recurrent colic case, you might have a bit more time to take a more thorough history to try and get some more clues. And it's those clues that are quite important in starting to formulate your ideas as to whether this horse may potentially be a horse that needs surgery.
And whilst taking that history, it's very useful before actually walking into the stable with that horse to actually sort of keep a rough, watch on that horse, just to see what kind of clinical signs it's showing. And many of you will be aware of the typical colic signs of pawing, flank watching, getting up and down, rolling right through to the violently painful horse, that can't be, kept standing. To those horses where you think, could this be something else and is this something that's non-gastrointestinal related?
So clinical examination, I'll go through the basics of that, but then you need to decide whether other diagnostic tests are required, which again will vary on the colic case. And then making that important assessment. And as I said, the aim shouldn't be for you to make a precise diagnosis.
Your assessment is, in the first instance, can I manage this horse medically? Should I be considering potential surgical management in this horse? And then a plan for how you're going to analge this horse, provide other treatments, and importantly, as I'll come back to a little bit later, the plan for reassessing the horse.
So coming to our history and a little bit of knowledge about our horse, quite a lot of work has been done over the last 20 years or so, looking at the epidemiology of colic. And, there are, there are a few reviews. I've put one up, one that I did a few years ago.
There are other, reviews as well. But just summarising, what we know about risk factors for colic in general. And increasingly what we have identified during that time is that some of these risk factors are different for specific types of colic.
And that's something that can really be helpful when you're trying to start putting that jigsaw puzzle together. So some work that I did a number of years ago, horse owners, it's sort of well known sort of theory that horse owners, associate colic cases with the spring and autumn, and we did some work looking at, the seasonality of colic to see if there are typical types of colic that can occur during different seasons. This is an open access article if you are interested in looking at it.
So you can see that grass sickness, which we used as a sort of a guide, we know that that in the UK occurs in the springtime. So that model that we ran confirmed that yes, we've got a model that works, but you can see at the bottom that the large colon displacements and torsions indeed, and as with all medical and all surgical colics, these are more common during these months. But surprisingly, we saw things such as epiloic frame and entrapments that tend to be more common in the winter.
So obviously this is alone isn't gonna help you necessarily when you're seeing a horse in November, but again, putting all the bits of the jigsaw puzzle together, it might help you, start to work out what's more likely or not. So when you're taking your history, things that you would want to know is the breed, age, and sex of the horse. Obviously, stallions, you would always, always want to check for inguinal herniation.
Management of the horse, is the horse stabled? Is it outside? Is it a mixture of both?
What type of feed is it on? And importantly, we know that a risk factor for colic is change in that management routine, and particularly within the preceding, few weeks, such as within the last 30 days. Also, I'm sure many of you know that high parasite burdens can be associated with increased risk of colic, as can horses with known dental problems, and particularly, for example, tapeworm infection and spasmodic colic and cecal interceptions, and, dental pathology with things like large colon impactctions and what we call simple colonic obstruction distention colic.
Stereotypic behaviour is interesting, and, as some of you might be aware, crib biting and wind sucking behaviour, particularly horses who demonstrate this for longer periods of time during the day, are not only more likely to have had a previous history of colic, but we know that certain types of colics, such as epiic frame entrapments and these simple colonic obstruction distension colics, things like large colon impactions or simple large cololon displacements. Are again more common in these horses. As with any horse with any problem, it's always good to get an idea of other medical, problems, medication that they're on, for example, horses that have been on non-steroidal anti-inflammatories for a long period of time, and whether this horse has had colic episodes before, particularly if these episodes seem to be becoming more frequent and more severe in nature.
Other clues, that we might think about, and it's been shown in several studies now, is that older horses and ponies would be at more risk of pedunculated lipomas, particularly affecting the small intestine. So if you've got an older pony, severe signs of pain, distended loops of small intestine or rectal examination, certainly doesn't guarantee that diagnosis, but the likelihood of it being something like that is higher than, for example, a small intestinal vulullus that might be more common in fos. Sorry.
We also know that brood mares, the time around, parturition, and certainly for the 1st 90 days, they're at increased risk of large colon vulvulus. I've already mentioned horses that crib bite or wind suck, but horses, for example, this is a group of horses kept on a sand paddock, for most of the time during the day and were being fed off the, off the ground, had a problem with recurrent colic. Perhaps no surprise that this was related to accumulations of sand in the colon.
And then, again, from some of the seasonality, times of the year when maybe horses aren't turned out as, long, and we know that, types of colics such as large colon and impaction, which are very unlikely to occur in horses kept at grass, they would be much more likely. So it certainly doesn't present a whole jigsaw puzzle, but it helps you to start piecing that puzzle together. So initial questions that you would want to ask the owner is what sort of signs they've observed when they started.
And of course, a horse might have been found, collicking violently in the stable first thing in the morning. So you want to know when the horse was last seen to be normal to get some idea of when the horse might have actually started collicking. This just gives you a little bit of a global overview on the situation.
It's important to know how much feed the horses taken in and what sort of faecal output it's had in the preceding 24 hours and obviously whether they've noted anything such as diarrhoea, within that time period. So, as I've mentioned before, most cases of typical colic would be gastrointestinal related. But remember that some horses might not show overt signs of colic.
So this little pony at the top pictured here is a pony that's got gut that is has been strangulated for a long period of time. You can see it's obviously Bashed itself around a lot, but the gut is dead, and this pony is exhausted. So it's not actively showing any signs of colic pain.
So late stages of colic, you might just have a very dull, depressed, horse with, or pony, with, signs that they probably have been uncomfortable at some stage before. Remember that horse owners might assume that a pony, for example, that's been recumbent, might obviously have colic, but it might actually be something like laminitis. At specific times of the year in certain regions of the world, you might be more concerned about things like atypical myopathy, or occasionally, you may get lesions such as urolithiasis that cause urinary tract obstruction, such as this horse that's got a urolith causing the bladder to become absolutely massive and close to rupture.
The horse obviously was showing signs of abdominal pain, but these were related to the urinary tract rather than the gastrointestinal tract. So some subtle observations may help you decide whether this is a true gastrointestinal colic or whether there's something else going on. So in your initial examination, the standard examination out in the field would be to get the horse's heart rate.
And it's quite important that you do this prior to administering any drugs such as aspan compositum, which can alter the horse's heart rate, and obviously any sedative agents that will also, alter the horse's heart rates. Mucous membrane colour gave you something that I, I think is probably not as useful as heart rates, but can certainly give you an idea. And certainly if a horse has got very congested mucous membranes or purple mucous membranes, or has evidence of a toxic line, then obviously you need to be concerned, but typically those horses will have very altered, abnormal tachycardia as well.
Respiratory rates, obviously that may reflect pain, but don't forget you do get the odd horse with plu pneumonia that might mimic colic, or the occasional horse that's got a diaphragmatic rupture and is very tackyic and dysic. Listening to the horse's, gut sounds or intestinal bulbug me, again, a very basic thing, but it's really important. So, knowing whether the horse has got any gut sounds at all, whether they're hypermotile, which might indicate some form of impending, diarrhoea, episodes or spasmodic colic, or whether you've got a very quiet abdomen, which, might be quite concerning with regards to a potential surgical lesion.
Taking the horse's temperature, quite important. Again, you may have some horses with impending colitis, obviously it wouldn't be managed surgically, but, obviously you need to be aware of that before sending to any hospital, with a potentially infectious, problem. Digital pulses again ruling out laminitis, and, checking for any evidence of perhaps impending laminitis.
And out in the field, obviously, you're not going to have the haematology and biochemistry equipment there, but you may take blood to run once you get back to the practise. And things like systemic lactates and measuring total protein and pack cell volume are something we would routinely measure within a hospital situation. And there's no reason why you couldn't measure that once you get back to the practise to have a baseline idea.
And certainly lactates, something very portable, can be done out on the yard, and I think it's something very valuable, for the, vets out in the field, particularly peritoneal lactate, in, in looking at using it just adds an extra little, jigsaw piece to that puzzle. Brectal examination again is something that many of you will be familiar, and obviously, you don't always have the luxury of stocks to examine a horse. So out in the field, you may have very limited facilities.
Most horses will tolerate this reasonably well, but there may be some horses where the risk to you and the handler is simply not worth it. So, it's important that if you have got a horse, particularly one that's straining or is difficult, threatening to kick, that you don't wreck all, a horse over a stable door in case they go down, because obviously that could cause quite severe injury. You could always use a couple of hay bales to protect you if the horse does try and kick.
Sedation is very useful in those, more difficult horses where they're straining, but just remember that sedated horses are typically unpredictably unpredictable, and they can still, give you a, a pretty nasty kick, usually with very little warning. Just mentioning about the handler, it is really important to have somebody competent at the front end as well. And as you'll be aware, administering something like butyl scopolamine can be very helpful in the horse that strains.
You're then gonna do a systemic palpation of the caudal abdomen. Obviously you're not gonna be able to palpate much more than that. And remembering that in very small ponies or folds, it might not be possible.
And when you're not able to perform a rectal examination in these cases, that important bit in that jigsaw puzzle, you appreciate just how much information that rectal examination will give you. So I'm sure many of you will be very familiar with the the contents of the caudal abdomen and what you should be palpating. But again, don't become fixated on a specific diagnosis, and I think you need to keep it fairly simple.
Is there room in the abdomen? Generally, if you've got an abdomen that feels fairly relaxed and you can move your arm around freely, I would be less alarmed. But if you can barely get your arm into the pelvic canal and you can feel in viscera pushing back, I would be much more concerned about some type of surgical lesion.
And then can you feel any distended intestine or any abnormal masses? And remembering that the size of what you're feeling will correlate with the structure that it's likely to be. So things like seek and remember, vertical band, it's fixed to the body wall, you can't get your hand around the top, whereas large intestine have tenia, might go in variable directions and you can generally get your hands, round over the top of them.
And don't forget the small colon as well, because sometimes that can confuse people. Nasal gastric intubation again, something many of you will be familiar with, and you'll know that normally, you should get a net of less than 2 litres in adults, less than 500 millimetres in folds. But I think the important thing to remember is that just because you don't get nasogastric reflux does not rule out a surgical lesion.
Again, it takes time for that fluid. If you've got a, say, a small intestinal obstruction of lium, it's gonna take many hours for all that fluid to back up through the entire length of the small intestine and for the stomach to become distended. So it's just another bit in your jigsy puzzle in that if you do get positive nasogastric reflux, that is pretty important, but if you don't get reflux, that doesn't rule out a surgical lesion.
Abdominalcentesis, again, another valuable technique. I'm sure many of you will be familiar with how to do it, described in many texts. Very simple ventral midline, most dependent part of the abdomen.
I usually use a needle. Remember that if you've got a pretty fat pony, and particularly donkeys, they often have a lot of retroperitoneal fat. You might need to use a spinal needle.
If you've got any concerns, some people use teat cannulas, and that can be useful if you have to obtain peritoneal fluid, and, for example, in, horses where you think there's distended small intestine. To be honest with you, in those cases, I think probably they are ones where it is highly likely that there's something surgical going on, but you may just want to have that reassurance of knowing what the abdominal fluid looks like. And just be aware, distended small intestine, there is a risk of intestinal laceration using a needle and remember in folds, the small intestinal walls pretty thin.
So normal peritoneal fluid should be yellow and clear, should have low total protein and lactates. But remember that in the early stages of some surgical lesions, the peritoneal fluid can look pretty normal and it can often be fairly normal in terms of protein and lactate values. So the key take home message is don't wait until that peritoneal fluid starts to become discoloured, because, for example, this The orange, fluid correlates with a horse that's got many feet of distended and discoloured, and necrotic small intestine, whereas a small loop of small intestine, actually may generate very little initial changes in the peritoneal fluid values.
And research has shown that any sequential increase in peritoneal lactate can be a very sensitive means of detecting a likely surgical lesion. So again, if you don't have a pair a lactate metre and you're interested in it, there's quite a lot in the literature and it may be something that adds to that jigsaw puzzle that you can put together more accurately. So just to talk about abdominal ultrasound a little bit, and just to show you that it is a technique that can be used in practise, and it's particularly useful in folds, but I'd say probably more practitioners, certainly in the UK, certainly in the US would be using it as I think more people have the ability to access this and make a routinely carry such equipment in the car.
Most, transabdominal scanning is done per percutaneously, but don't forget fairly simple linear rectal scanners that you use for pregnancy diagnosis. You could perform per rectum ultrasound examination as well. So most transducers would be microconvex, but you could use a linear rectal probe.
And remember, the penetration, the depth of penetration that you need often requires a transducer that may go as low as 2.5 to 3.5 megahertz.
But for more superficial structures and certainly for imaging folds, you may need one with a slightly higher megahertz, which is more consistent with some of the more mainline and ultrasound machines being used. Patient preparation depends a little bit on where you are and what the season is. If you've got a, a thoroughbred horse that's got a very thin hair coat, you may be able to scan just with alcohol application and gel to the skin alone.
But if you've got a thick hairy horse in the depths of winter, you may need to click. And obviously that does have implications in that if you've got a horse that's quite clearly sick, you don't want to waste time clipping the hair coat if you've got a fairly good idea that it's gonna need surgery. But in some cases it may be useful and particularly where that decision is unclear.
And I would recommend, I've given you a recommended, text, which is the practical guide to equine colic by Louise Southwood, which has got a very nice section on abdominal ultrasounds. But also there's a really nice article in veterinary clinics of North America, equine practise that runs through how to perform ultrasonography of the equine acute abdomen. As I said, there are many texts that cover this, so there are other texts that cover it quite comprehensively as well.
So what I'm gonna do is focus on what vets out in the field might be able to use. As I said, in a clinic situation, you have the luxury of, probably slightly more advanced, equipment, stocks, the ability to, image a horse with, lots of people helping, which obviously you might not in the field. So there's a nice paper that was published in the Veterinary Journal in 2011 that describes a technique, similar to one that they use in humans to rapidly assess a human's abdomen using the ultrasound, and they've, termed this the flash technique, and it uses seven key windows in the horse to image specific parts.
Of the equine abdomen to assess various areas such as the gastric window, looking for small intestinal distention ventrally, and looking at the mid abdomen, and then looking at other key areas such as the left paralumbar fossa, which is obviously where you've got your nephrosplenic space, and looking at the duodenum on the right-hand side. So, it's a fairly easy technique to perform when you know how to do it, and they, and 15 minutes, they reported it would take trained personnel to do. Full abdominal assessment is obviously something, particularly with recurrent colic cases undergoing a very thorough examination.
It does take a little bit more time, and obviously, if you've got a horse with very hairy hair coats, can add additional time that you might not want to waste. So might be something that is more performed in a clinic situation. But what I would encourage is if you are in practise and you see colic cases and you do sometimes carry a suitable ultrasound machine with you, have a go at just doing a limited assessment of colic cases because give it a try.
Practise makes perfect and it can be really. Useful. So we have a horse that's pretty painful, where it's fairly obvious it might need surgery.
Just putting the probe up into the inguinal areas, which haven't got much of a hair coat, can do it very quickly and very simply. Just putting that probe on and identifying distended loops of small intestine or the ventral cranial midline, where you're going to do your abdominocentesis, having to clip it and surgically or aseptically prepare it anyway. Just those 3 windows can give you some really valuable information.
So, so if you haven't tried it before or you don't do it very often, it's something that I think can be very, very useful in practise. So things that you're going to assess are peritoneal fluid, if there's any other abnormal quantities of free fluids, gonna assess small intestine and large colon, looking at things like motility and distension and wall thickness. We're looking at the stomach, as well, depending on the window that you use, and areas such as the nephrosplenic space or the duodenum.
And in fals, particularly if they're colicing in their lateral recumbency, it's really important to make sure you assess the dependent portion. So for example, a heavy, strangulated bit of, intestine is probably gonna fall ventrally, and also remember to check the umbilical structures as well, which again are very, fairly simple to assess with, an ultrasound. So just running through a few videos and a few slides, so the horse at the top right here is a horse that's got peritoneal fusion.
You can see the retroperitoneal fat here, you can see this is the outline of this large colon, and you can see large quantities of hypo and ecogenicity consistent with fluid in the abdomen. Whereas this horse here also has what appears to be free fluid, but it looks much more ecogenic. And if we just play a short video clip, this is a horse with hemo abdomen, and the blood has a very classic swirling, smoky appearance, which you can just see here.
I'll play this clip a couple of times. OK. Then, small intestine, normal in small intestine has a sort of a sandwich-like appearance of hyperb and hypo and hyperechoic areas, but should, oh, sorry, I've gone on one slide, should normally be a fairly thin walled, around about 3 millimetres, and should have very good and propulsive and contractile activity.
So I'll just show you here what a loop of normal small intestine should look like. Again, I'll play it a couple of times. So that's what you want to see.
There's just a couple of loops of small intestine there, nice mixing movements, and you can see the small intestine contract down. What would give you a fairly good clue as to a surgical lesion or potentially in the case with, for example, an anterior enteritis lesion that you might treat medically. Is evidence of multiple loops of distended small intestine.
And I'd say it's, well, it's been shown in studies to be a much more sensitive and specific way of identifying distended small intestine, which invariably would be something that might need surgical intervention compared to just rectal examination. But it's not just all about having distended loops of small intestine. You also want to look at the wall.
Is it thickened? In this horse, there are amotile loops of distended small intestine, but you can see that the wall looks relatively normal in thickness. So this might be more consistent with a non-strangulating lesion, a simple obstruction, or perhaps a portion of small intestine proximal to a lesion that doesn't have compromise of the bowel wall.
In contrast, this blow is a horse with an epiloic frame entrapment. This was actually a scan taken in the right cranial ventral abdomen, and you can see that the wall can see this distance here is about 1 centimetre, so you can see you've got very thick and small intestine, consistent with edematous loops, likely to be strangulated and require resection. So here's a little video clip, once seen, never forgotten, I would say, this small intestine, you can see the loops, you can see this middle loop here has got some, activity, some propulsive and contractile activity, but the loop that's closest to the abdominal wall is sitting there really doing nothing.
So that would give you a fairly good idea that there is something more complicated going on here that may well require surgical intervention. So the nephrosplenic space again can be imaged fairly easily in the left paraimbar fossa. And what you're wanting to identify is this sort of homogeneous appearance of mixed ecogenity ecogenicity that the spleen has, and the, appearance of the left kidney you can see the, renal structures here, the pelvis, the cortex, and the dulla.
And then you've got normal large colon that sits on the axial portion of that. If you are unable to image these areas, and all you can see is gas-filled large colon in these areas, it might give you more of an inkling together with rectal palpation, history, etc. That you might be dealing with a horse with a nephrospanic entrapment.
And then coming on to large colon, again, normal wall thickness, round about 3 millimetres. but in horses that have, and you're assessing for motility as well, and so this is the right dorsal colon in the horse, so you can see again, propulsive activity, here. In a horse that has abnormal large colon, then you're going to typically see things like a thickening of the colon wall.
So these, this is a horse with right dorsal colitis, but in your horse that has a large colon vulvulus as well, identifying aematous thickened large colon will give you an extra little piece to that jigsaw puzzle. So hopefully that has persuaded you that even if you're working in practise, seeing horses out in the field, if you've got access to a suitable ultrasound machine it's something that you can have a go at and it can be very useful, particularly picking up those horses with distended small intestine, which I think is quite easy to do. Just coming on to a few types of groups of colic where I think the jigsaw puzzle can be a little bit more complex than your typical adult horse, and that's the little darling neonatal foals, and they can be a real challenge to work out what's going on.
And certainly in these cases, the degree of pain is much less useful because medically treatable lesions such as enteritis can actually appear present with folds with quite severe signs of abdominal pain. Ultrasound is really useful and remember that you can also radiograph them due to their size. This is a a fold with necrotizing enteritis that has got very thick and small intestine here and you can see little gas pockets here.
I'd actually like to acknowledge my colleague Fer Fernando Malala, who's provided a number of these ultrasound images for this presentation as well. And don't forget, thinking of the epidemiology, foals are much more likely to have things like meconium impaction, ruptured bladder, small intestinal enteritis, vulvullus or congenital anomalies compared to your typical adult horse. Don't forget as well, donkeys get colic, and they're not usually quite so obvious in terms of colic signs throwing themselves around.
Dull donkey could have anything going on, it could have quite a severe intestinal lesion going on, and still look dull rather than very colicky. Remember that large colon impactions are quite common, and I think people forget that or don't realise that rectal examination can be performed safely in most, except the very small donkeys. As I've already mentioned, they can have a lot of retroperitoneal fats, and so you might need a spinal needle.
And if you do have a donkey that's had an impaction, always make sure that you follow this up with, dental assessment and treatment if required. So coming on to our decision, making about recognising surgical cases early, I hope I've persuaded you that you don't need to make a specific diagnosis, but you need to make a decision, is this medically treatable or does this need surgery? And here are a list of the criteria that might point towards, medical treatments.
And here are some criteria that are generally taken to indicate a a horse with a more surgical lesion. But remember, you can have horses with surgical lesions at an early stage that might have relatively normal heart rates that don't fit with this, might have no net reflux. So I'd say that there's no one easy thing to say whether a horse is necessarily medical or surgical.
It's putting these and deciding which is the most appropriate category. And I would say of all the most useful things is pain and recurrence of pain. And obviously euthanasia, there are some indications where you've got a horse that's got something, that would potentially have been surgical, but obviously surgery is not an option, you then have to euthanize.
But if you've got a horse that's probably unlikely to survive surgical intervention. Where gastrointestinal rupture has occurred, then these horses should be euthanized rather than them collapsing and dying as in the horse pictured, on the way to a referral centre. So again, these are just some criteria here for horses that probably should be euthanized.
And as I've said to you, you don't need to make a specific diagnosis. You need to think, based on your findings, do you think this is something severe, such as the mare that you examined, post bowling, very painful rectal examination, abnormal, you can just feel distended large colon, could be a colon torsion. But don't become fixated on an initial diagnosis.
So, for example, this is also actually had a small colon impaction. But the vet became fixated on a different diagnosis and didn't think to consider that there might be something else going on. And unfortunately, the horse was then sent in at quite a late stage and we were unable to save it in the postoperative period.
So even if you think you've got a good idea, make sure you always reconsider, particularly if that horse is not responding to treatment. So, coming onto the plan. Well, if you've got a horse that's got potential surgical signs, you need to, if surgery is an option, get in touch with that referrals facility.
If you're not sure how to manage the horse prior to referral, analgesia, etc. Know about costs, etc. Discuss it with them.
The next few slides I'm just gonna focus on, I think an area that is really important, which is analgesia, and then finally, a repeat evaluation, which is really critical. So medical treatment, as I'm sure many of you will be aware, analgesia, maybe is often required, and you may need oral fluids, for example, in horses with a large colon inaction, and other therapies might be appropriate, depending on your diagnosis, for example, phenylephrine in trying to medically manage a horse with a nephrosplenic entrapment. But analgesia, you need to consider, obviously the main analgesic agents are shown there, but you need to seriously consider the potency, how long it's going to act and side effects before you administer it.
And my take home message would be to use a drug that you are familiar with and take into account its potency and duration of action. Gonna have a little bit of a sort of question. I think it's important for people to consider and flunixin.
I'm not saying by any means that flunixin shouldn't be used in colic cases, but generally, actually, our referring vets tend not to use it. They tend to go with phenylbutazone, or buttoscopolamine compositum, a bus command compositum. And if they don't respond to that, they will then generally contact us.
And the problem is, people will say to me in practise that all colics should get flunics in, and that you can tell they're surgical. And obviously, I don't think many of us are in the profession to necessarily get a good night's sleep if you're dealing with horses and potential colic. Yes, you can tell if they're surgical, but at the stage where they've got 30 ft of gut that needs resecting and a very poor prognosis, I don't think that's a good outcome for our patients.
So you need to consider that flunixin is really potent. And importantly, whilst you might appreciate the clinical signs, that horse owner may not appreciate the severity of the situation and may delay getting you back out. And remember, if you think of that jigsaw puzzle and those criteria for surgery, if you're using pain and increases in heart rates as clues that might help you to identify that surgical colic earlier, By masking the effects of those increases in heart rates and masking the signs of pain, particularly with these very small parts of small intestine that become strangulated, flu mixing can certainly making it much more challenging to get these horses to surgery at an early stage.
So what I would say that flu Nixon is acceptable, is obviously referral is not an option, the horse is very painful and you're gonna have to use it otherwise euthanize the horse otherwise. If you've got an exact diagnosis, for example, pelvic flexture impaction, that's fine. Or if you've already decided to refer the horse or the horse is so painful, you need to control pain during transport.
That's fine. And again, I usually advise people to discuss that with the referral centre because some people are, are happier with it than others. Where I would be cautious is if you've got hoarse with presented with colic, with mild to moderate pain, where you can't quite work out what's going on where referrals an option.
And if an owner is unsure about surgery, and owners often say surgery isn't an option, and then when they're deteriorating and it's then a decision to euthanize, they may well change their minds, so bear that in mind. And if you do use it, make sure that you reassess the horse or get the owner to call you back and make sure that they know that this horse really needs to be bouncing back, looking much more normal. If it's showing any signs of pain, they need to contact you.
And owners also had put their heads in the sand, and maybe some vets do, and desperately hope that a horse isn't gonna have a surgical lesion. But if a horse genuinely has got a surgical lesion, burying your head in the sand and delaying that decision making is only gonna potentially have a worse outcome for the horse. So, communication is key, and I think one of the key things that I think it's really important to get across to vets and owners is that it's not that horse that's making the decision.
It's not the horse ringing the vet to say, I feel painful, can you come back to see me? It is your horse owner choosing to pick that phone up at 2 o'clock in the morning and say, Can you come back out and look at my horse. So, you need to make sure that the owner knows how to manage the horse if you're deciding to manage it medically, what signs they should look for.
Any recurrence of pain is important and when re-examination might be performed. They should be allowed to make an informed decision. So I think it's wrong for vets to dictate whether surgery is maybe a possibility or not, unless you've got very good reason to do so.
For example, a bad debtor might, might be one example of that. But I think it is important that if If you do think a horse has got a surgical lesion, owners at least know what the costs might be, hospital deposits, possible prognosis, and importantly, if they decline referral to an early stage, what implications then sending the horse in later may have for the horse's survival and the cost of treatment. And also make sure that you communicate well with colleagues and the referral centre and referral centres will always be happy to discuss colic cases if you're unsure what to do.
So, to conclude, I think it's really important when assessing the colic case out in the field, particularly that horse that worries you a little bit more as to potentially being a surgical candidate, is to keep your mind open. Don't forget, you don't need to make a diagnosis on the initial or even subsequent examinations. You just need to decide whether based on your initial treatment and result and results of your initial and follow-up examinations, whether you think a horse is improving or deteriorating.
And I was always taught by Barry Edwards, who's, you know, one, a name I'm sure most people know with regards to colic surgery, and I think it always holds true. Non-response to analgesia is always the potential need, for surgery or euthanasia in the colic case. And certainly recurrence of pain, is something that should be treated very seriously.
So, early referral, I hope I've persuaded you, is a really important factor in maximising the horse's chance of survival. And you, as a referring vet, the vet out in the field, is absolutely critical to that decision making. We're relying on you to identify these horses and get them sent in early.
So if you want any further information, we do have a hospital website, information for horse owners and vets, and I hope you found the webinar useful. Thank you.