Good evening everyone and welcome to the webinar vets, equine webinar. So today's topic will be on penetrating, wounds in horses and why on ES. So just before we get started, my name is Ophia and I'm from the University of Liverpool, sorry, Edinburgh.
I graduated from Liverpool and now at the University of Edinburgh. So I'll just do a few housekeeping things, so you'll see there's a little Q&A box on your screens. So if you have any questions for the speaker, please feel free to put them in there, and then we You can ask them at the end of the, of the of the webinar.
Equally, if you've got any housekeeping or technical difficulties, then again, just put them in the Q&A box, and we've got Dawn as backup. So if there's any internet connection problems, then she'll be able to help you. So, just to introduce our speaker, so, Yvonne graduated from Ontario Veterinary College, in 1997, she then proceeded to a large animal internship at Washington State University and a large animal surgery residency at New Bolton centre at the University of Pennsylvania.
She then worked in the USA, after becoming a board certified surgeon for 10 years, and then more and more recently also at the University of Montreal vet school. She currently is now lead of the equine Hospital and full-time equine surgeon at Langford Vets equine Hospital in the south of England. So, enough from me, over to you, Yvonne.
Thank you very much. Thank you to everyone who's attending. So tonight's talk, will be on, penetrating wounds in horses.
If I can just get it to go to the next slide. Oh. Yeah, there we go.
And, penetrating wounds are something we see wounds all the time in equine practise, and certainly penetrating wounds are ones that will go into one of the cavities such as the thorax, the abdomen, the head, or more probably the most common that we see is those that penetrate into synovial structures. So the goal of tonight's talk was just to go through each of those areas of the body and what happens when a wound causes a penetration into each of those areas and how we can best deal with that? Can it be dealt with at the farm?
Does it need to be referred into the hospital, and what the options are. So we'll go through each of one of, each one of those areas in turn. So we'll start off with wounds that may penetrate into .
The thorax, but I think it's always really important that when we have wounds, they can be large or small, anywhere on the body. And the first thing that we have to do is not necessarily immediately jump to the wound, but to make sure That there has been significant blood loss or that the horse is in shock, and make sure that we stabilise the horse as a whole, before we dive into the wound itself. And I think that's important because sometimes they'll have a rather, you know, significant gloving injury for.
But there may be a small yet penetrating wound, which may be more important. So, I think it's crucial not to forget to have a quick look at the whole horse, and a quick physical examination to make sure that the horse doesn't have, issues that need to be addressed prior to the wound. And then once, we've done that, we can get to identifying what structures are involved in the wound and what decisions need to be made.
Before we get into wounds that actually penetrate into the thorax, I think it's important to mention that horses can get wounds in the axillary or pectoral region, which don't necessarily immediately penetrate into the thorax as the rib cage is very protective and so some of these wounds slide off along the side, and it requires a great force to get in between those thick ribs and intercostal muscles. But wounds that dissect up along the side in the axillary region or along the pectoral region. They may dissect into the thorax with time because they suck air in that air dissects along fascial planes, and that can, become an issue.
So if there's a large wound in those regions, that's something to keep in mind. As I said, they have a known risk of having a pneumo mediastinum or pneumothorax, maybe not initially, but certainly over the next couple of days is that air dissects along fascial planes, and some of them get a lot of subcutaneous emphysema and that makes examining them very difficult because they tend to. Have crackles under the skin.
And so when you're trying to sculpt the chest to make sure they have, you know, good lung sounds, that's not possible. This is a great example of, how they can have a penetrating injury that has a lot of force, but it's managed to be deflected and hasn't penetrated into a thoracic cavity, but been deflected along the sternum and under the skin, as you can see in the picture there. So wounds of this nature, the ones that go into the pectoral region or the axilla, and the important thing is they often are potentially too deep or there's too much torn muscle for them to be closed primarily.
If they can be closed primarily, that's great, but often they can't. And in those cases, I think packing them is important to prevent that emphysema both subcutaneously and that which may track along into the, the mediastinum or the thorax. So that can be done just simply with packing or as you can see in this picture, as with packing and, and an inclusive dressing of cling wrap or sometimes the, the blanket coverings can be used to help hold this in place, and certainly keeping these types of wounds treated with a systemic antimicrobial as well as analgesics is important because of that known risk of it starting to track along the fascial plains.
They have great ventral drainage, most of them, but I think because of that risk, the antimicrobials are warranted for a good 1 week to 10 days. So I wanted to talk about that quickly before we got into ones that actually penetrate into the thorax, and I think it can be quite difficult with some of these wounds, as in this picture and the ones that I showed before, does the object get into the chest or not? And When you read about these, there's lots of classic descriptions of oh, you can sculpt the chest and if there's, you know, no good lung sounds, that's because the lungs collapsed or you could do percussion.
Ultrasound is obviously much easier in a referral setting than it is in practise depending on which ultrasound you have. And the same with rachocentesis and radiographs. So they can actually be a bit of a diagnostic challenge and obviously, when you're presented with a penetrating injury such as this, both the horse and the owners are very distressed and that needs to be managed.
So I think it's important to recognise that sometimes you cannot be sure of where that penetration has gone and what it has affected, and, and, and it's important to talk about that with the owners that we may be finding things out as we go along. So auscultation and percussion are the two that are mentioned most when, when, you know, you learn in vet school or you read in textbooks. And part of the problem is that when a penetration into the thorax has occurred, this is very painful, and the amount of force that's required to penetrate into the chest, but also injuries to the pleura are very painful, and so most of these horses are breathing very shallowly.
And it can be difficult to hear if breath sounds are present. If you can hear lovely breath sounds on one side of the chest and there are none on the other, then that's nice and definitive that there is a pneumothorax and there has been a penetration, but certainly it it can be incredibly difficult to hear that. The one thing that can happen if there's bleeding into the chest that you can be listening in the dorsal called a lung field to to hear breath sounds, or lack of breath sounds, and you can clearly hear the heart, and that's because if there's been bleeding into the chest, that sound resonates through the fluid and so that's also a good indication that there's at least been haemorrhage into the chest and likely some degree of penetration.
So I certainly always try to auscultate them for breath sounds, but I'm not surprised if it doesn't actually give me a definitive answer. Ultrasound can be, also very nice as, lots of times if you have an ultrasound with which you can do this, looking between the ribs, you can usually readily see the, the plural, surface moving back and forth. And if you can't see it or you can see.
A lot of space and blood, then that is an indication of penetration as well. This depends a little bit on your ultrasound and also a little bit, some of these horses are quite painful and certainly in most cases, I would be giving them some analgesia prior to attempting these diagnostics. Thoracocentesis is something that can be done fairly readily.
Oftentimes, out in practise using a teak cannula with a three-way stopcock can be done. You can use an intravenous catheter, but there's a little bit more chance of inadvertent damage to the lung if it's not collapsed away. And certainly chest strains are obviously what we commonly use in a hospital setting.
But if you place a teat cannua through the ribs and you can aspirate easily with, with no resistance, then there has been an, there is a pneumothorax present, as if you place, you know, a blunt, teak cannula or, or. Cannula of some kind and aspirate and the lung is right there, there'll be some resistance to your aspiration. This is usually done dorsocaudally.
This is actually a picture of a horse having it done to remove some fluid, but usually dorsocaly around the 13th to 16th rib, depending on the size of the horse. So I think the big question to do a lot of these cases, as I said, there's a big object such as this penetrating the horse, and certainly when people think about penetrating injuries, the sort of the adage is not to pull out the penetrating object, and certainly if there's a child or a dog with a penetrating object, I would definitively say not to pull it out. This picture is a great example of how sometimes that may not be practical if you're thinking about shipping a horse into a hospital setting to be treated.
Certainly when horses are in transport, they will sway from side to side. And the other really practical consideration is if you have a dog, for example, that has a penetrating stick injury that actually goes into the heart or one of the major vessels. That dog could go to surgery, have the chest opened up, and potentially the penetrated, heart or or major vessel repaired, but we're not quite able to do that in horses.
So from a very practical point of view, if that object has penetrated into one of those structures and you remove it and the horse promptly bleeds to death, that's probably what's going to happen regardless of the setting in which it occurs. So if You have a horse in this situation. I think that you can think about removal being very justified.
I think, as is being done in this picture, one of the first steps when, when faced with this situation is to potentially place an intravenous catheter, so you have good access to be able to administer the horse both antibiotics and analgesics for pain control as they're very painful. And also, if things start to go wrong, you have an immediate access in which you can administer either increased amounts of sedation or worst case scenario, some euthanasia solution. So the way that I approach them is to do a quick physical exam of the whole horse without touching the object or the wound and place an intravenous catheter, administer some medications, antibiotics, and analgesics, and then I prepare to address the wound itself.
Usually, I'm having a conversation with the owner about whether or not referral is an option in a situation like this, and then I can make a decision about where to go from there. The one sort of practical component is if you are going to ship a horse with this object, so you're going to remove it. Obviously, if it's a very large object such as this, I would cut off a length of that, so you're not pulling a large amount back through the wound.
You can try to cut off very close to each side of the animal and ship it with the object still in place, but you wouldn't want it to be pushing the object further in in a trailer, and so I think oftentimes pulling it is practical. If you do that, I usually am very prepared to pack the wound with large towels and a bandage that goes all the way around the chest. Oftentimes, again, using saran wrap, sorry, that's very American, or what we call clingfilm here, to seal off and prevent any air sucking in, followed by some vet wrap all the way around the chest, would be appropriate.
So I think it's important to remember not to pull penetrating objects, in other species and sometimes in horses that's not practical and we have to go ahead and take the chance. The other good thing with horses, and this, is, most of the time to with adult horses is that theoretically, horses have an incomplete mediastinum, meaning that if they penetrate, with a wound on one side, they should get a bilateral pneumothorax. But as horses age, they often seal off that incomplete and more.
Than, more often than not, they have a unilateral pneumothorax from a penetrating injury. And so they tend to cope fairly well with having a unilateral pneumothorax. And even some of the ones I've seen with bilateral pneumothoraxes have, have been shipped in, and managed to, to cope with that.
So, If they do have a pneumothorax, you don't necessarily have to address that prior to referral, if that's an object, if that's if that's feasible for the horse, if the horse appears to be relatively stable and is breathing regularly, even if shallow in nature, then it can probably withstand being shipped. This picture is a picture of unfortunately a very old and blind brood mare who was on a farm with some construction and has driven. A fairly decent size 2x4 into her chest.
She was actually shipped in with this as they felt they could do that safely, and they had buffered it with towels and were unsure of where the other end of that piece of wood was. The good thing about penetrating thoracic wounds is that the survival is actually very good. There's a lot of force that's required to penetrate into the chest, but usually once the penetration has occurred, the lungs immediately drop away from the chest wall, and it's very unusual to have damage to the lungs, unless we're talking about a gunshot injury, in which case it's quite common to damage the lung tissue.
But with wood or stakes or things like that, usually the penetration actually doesn't go that deep in between the ribs and the lung drops away. So, in one study that's been done, obviously, nobody sees enormous numbers of these, but most of them were alive as long as the penetration didn't involve other things. So in a horse where it went into the chest and then into the abdomen or into the chest and then into the spine, those cases did not survive.
But if it's into the side of the chest and doesn't affect anything else, then the prognosis is actually usually very good. The one thing that can occur, is that the lateral thoracic vein runs just below where this wound in this picture would be, and they can often have some significant blood loss if that is involved in the wound itself. And this wound is one example of where it didn't initially penetrate, but certainly you would be concerned that as necrosis and time occurs that there could be some pneumothorax or just translocation of bacteria into the chest.
So with the penetrating thoracic wound, if it's an option to refer the horse, I think that is the recommended treatment. I would remove the object if that's the best way to ship the horse. As I said, giving, placing an intravenous catheter and giving antibiotics and analgesics, packing the hole once you pull the object, give it a quick bandage and send it in.
In the hospital, and what we tend to do is a standing, a surgery to just to address the wound, to clean it out, to flush it out, to close it if possible, or continue to pack it, if not, to reinflate the lung, and give the horse some supportive care such as oxygen and fluids with generally a relatively good prognosis. It's surprising actually that most of these horses do not go on to get a raging pleuritis or pleural pneumonia. Again, just because the object often doesn't penetrate in particularly far.
If referral is not an option, and this is, these pictures are that, blind brood mare who who, who got the penetrating stake. She was referred, but I just use it as an example. Again, I get, I prepare myself and the horse.
I give antibiotics generally broad spectrum, such as a penicillin, and a gentamicin unless the horse is particularly dehydrated. And I will give a good dose of either Flenexin or phenylbuasone. Place local anaesthetic, usually just in a simple ring around the wound.
If I'm in the field and I'm addressing this and I have a high suspicion of penetration, I think it's good to pre-place either a blunt cannula or a chest strain if you happen to have one in the caudal dorsal lung field around the 14th or 15th rib. And be ready to aspirate air. A lot of time when you remove the penetrating object, it's very obvious immediately if it's gone into the chest cavity, as there will be lots of air sucking in, making quite an obvious noise, in which case you clean very quickly and pack it and aspirate the pneumothorax, excessive air out the chest drain or the blunt cannula.
I will say if you're using a cannula, it is amazing to me how long it takes to aspirate air if you're using a three-way stopcock and a and a large syringe, obviously in a referral hospital you have the benefit of suction that makes your life easier. And I just get ready to explore the wound, to close the wound if possible, to pack, if not, but also prepare both yourself and the owner that if, for example, this had penetrated into a major vessel such as the caudal vena cava, or the aorta or the heart, when you pull it, there'll be a large gush of blood and things will be very exciting for a very short period of time. And, and that's just getting people ready, and getting them to realise, communicating with them, that that's what may happen.
Penetrating abdominal wounds are a little bit different, and they tend to have a fairly poor prognosis. So I think it's important that both of these are quite dramatic, but chest wounds tend to do very well unless they're particularly unlucky, where abdominal wounds tend to not do very well. And that's because the intestines and the internal organs can't drop away from the wound as the penetrating object enters like the lungs can.
And so if it penetrates into the abdomen, it's very likely that that will hurt either an internal organs such as the liver, kidney, or spleen, or into the intestines, which results in gross contamination of the abdomen with feed. This picture is of a horse who's obviously under anaesthesia, but has a penetrating stake. The diagnosis that a had entered into the intestines was relatively simple as there was a greenish brown fluid entering, exiting the wound around the stake, and which smelled distinctively of ingesta.
So the problem with this is either the severe peritonitis that results or the penetration of an internal organ such as liver, kidney, and spleen. Result in those organs losing function, severe bleeding, or in the case of the intestines, a really severe peritonitis that's quite difficult, for the horse to recover from. So the prognosis is quite opposite to that that occurs with the chest.
And while I may suggest attempting to treat a penetrating chest wound on the farm if referrals are an option is if you can pull out the object and you can suck the pneumothorax, suck the air out of the chest and resolve the pneumothorax, and that horse has a fairly decent chance of recovery, and if indeed in the next 7 to 10 days it develops a severe complication. You know, it, it was probably worth trying, but with an abdominal wound, I think that they either need to be treated in a referral hospital setting in order to effectively address the damage to the internal organs or potentially euthanized at the farm. So with abdominal wounds, it can be again, quite difficult to determine if the abdomen has indeed been penetrated.
And I think sometimes we get a little bit sensitive about the fact we don't know immediately what's been penetrated and I think we have to realise that it can be quite difficult when we have large wounds. And large not necessarily completely compliant patients to determine what's involved. With the abdomen, they can either penetrate or they can track up fairly commonly between the abdomen and the hind leg without actually going into the abdominal cavity.
So what we use to determine if the abdominal cavity has been involved in the clinical signs. Certainly, I've seen several who've had a wound that was thought not to penetrate, but within a few days, you know, sort of, you know, 2 to 3 days, I start showing signs of significant sepsis, and colic. Initially, obviously, some of these wounds will have significant blood loss.
And if possible, an abdominnocentesis will tell you if there's been significant contamination of the abdomen with faecal material. In the case of a wound such as this, which is a degloving injury from going over a fence, it may not be possible to perform an abdominocentesis. Sometimes rectally, you can get a feel if there's a ruptured viscous when the when the loss of negative pressure causes the rectum just to be very sucked around your hand.
Ultrasound can be used to determine if there's an excessive amount of fluid in the abdomen. And certainly an exploratory, laparotomy sometimes can or exploration of the wound itself can reveal, whether or not there's a penetration through the muscle walls into the belly. And as I pointed out in that previous case, if there's a, sometimes there's a very clear and obvious answer with the exudate that's coming out around the, the penetrating object.
Once again, I think these horses need to be addressed systemically prior to addressing the wound. This horse, for example, with this degloving injury, had suffered significant blood loss and required a blood transfusion because of the lateral thoracic vein had been completely lacerated, as well as that muscle trauma that you can see. We were unable to determine immediately if there is penetration into the abdomen just because she was in severe shock.
She was shaky, it was difficult to keep her standing. So we addressed that by placing a catheter and giving her fluids and eventually a blood transfusion, and then returning and you know, a bandage around the abdomen until she was stable enough to actually determine whether or not that there was a penetration and then addressing the wound itself. So abdominalcentesis, again, this is one of these wounds that tracks up between the flank of the horse and the, the, leg.
And so being able to do an abdominal centesis at the most central point of the abdomen, is a good, a good way to determine if there's been gross faecal contamination. Some red cell and blood contamination would be expected even just from the blunt trauma, so that wouldn't immediately make me think there had been penetration. But certainly having a very increased amount of blood would concern me having an increased white blood cell and protein or having feed material on the slide.
And sometimes it is obvious when you do an abdominocentesis and sometimes it may need to be returned to the clinic for a cytology. So with penetrating abdominal wounds, referral is a good option. And in this case, if it's possible to leave the stake in, such as in that horse where it went in ventrally and where it's in a place that won't be disturbed during transport, that's good, but if it has to come out to prevent further damage during transport, that's what has to happen.
And the owners need to be aware that abdominal lava and exploration with general anaesthesia may be necessary. And like I said, a fair number of these track along the fascial planes, particularly between the hind limb and the, the flank of the horse, without penetrating in, cause again those, those abdominal muscles are quite thick. This can be difficult to determine with confidence and even with the best efforts sometimes it will become obvious within a few days' time, and how the horse does, and that requires good communication with the owners and and managing their expectations.
So just to give you some results of these ones that I showed you, these 3 horses, so one with an obvious penetration of a stick, with green and brown exudate, one with a large degloving injury that went very deeply into the musculature of the abdomen, and this one where it went between the leg of the horse and the flank. So unfortunately the one in which it penetrated into the intestines, the stake went into the large colon and up into the pelvis, and despite several abdominal lavages, that horse ended up with severe adhesions from the peritonitis and did not survive. The horse with the large degloving injury did not penetrate significantly into the abdomen.
There was no penetration of the intestines. There was a fair amount of bleeding and potential minor translocation of bacteria, but no physical penetration of an object. And so this, after the horse was stabilised, was treated with surgical debridement and closure and with several drain.
Left in place due to potential dead space. As you can see, the, the vasculature of this most cranial portion of skin was not the best and that did eventually slough. But unfortunately, it sluffed after there was some nice granulation tissue and eventually everything all healed up.
With this horse, it was determined with abdominal centesis and ultrasound, not to have penetrated, but to have tracked along between the the flank and the hind leg. It was initially closed but rapidly broke down, which unfortunately is what most of these tend to do, just because of the, the movement is impossible to to restrict fully. And this was actually treated with negative pressure wound therapy, so it was packed with foam and subjected to an intermittent negative pressure which causes the wound to fill in quickly with granulation tissue, and the horse ended up doing well.
This horse, and the previous horse. We maintained on 2 to 3 weeks of antibiotics as it was felt that even though there wasn't a direct penetration, there was bleeding on the abdominal side and the potential for the development of peritonitis, but both did very well in the long term. So Other penetrating wounds, the sort of the two remaining categories to talk about are potential wounds of the head and those that go into synovial structures.
And with the wounds of the head, there's lots of important structures in that area that aren't covered by anything much other than skin. So, there's, you know, eyes, and the sinus, as in this horse, . The brain is not too far away, and obviously that can affect the structures around the pharynx and larynx as well as some of the external nerves.
With wounds of the head, again, I think they're not quite as painful as those big wounds of the abdomen and the chest. The horses tend to be less painful, but they can still be quite shocking for the owners and, and I think, obviously very distressing. So, it would seem more obvious with the head.
The structures are all fairly external, but if there's significant swelling, or bleeding, it can be, harder than it should be to assess exactly what's all involved. My one main key for wounds around the head is that it's easy for us to check for obvious neurological deficits. This course obviously has an abnormal ear posture.
The head is, is, is twisted and it has some facial nerve signs. So that can be fairly obvious. There can be swelling around the nerves or it can be severed in the actual injury.
But the main thing that I look for is a, is a depressed mentation. Now they can be a little bit quiet cause they've had a wound and they've obviously, you know, had a bad day, but if they're more depressed than you think they should be, that's almost always been a very good indication that there's been some cranial trauma. So either direct trauma to the brain case with injury or even just edoema from the blunt trauma surrounding the area.
So, of course, with depressedmentation, I'm very careful. And then I do warn the owners that without advanced imaging, it's impossible to be sure, but there may be some deeper injury either around the brain or just from blunt trauma causing edoema and swelling of the brain. Just going through some case examples of wounds to the head just to go through some of the principles.
The nice thing about wounds in the head is that there's a good vasculature of the head. They tend not to get a lot of infection, or if there is infection, they deal with it quite well and they tend to heal quite well. The bad thing is that when they penetrate into the sinuses, And they, and they have a sort of a contaminated structure that we don't, we want to be able to close all that up so they don't get a lot of subcutaneous emphysema or fistula, a chronic fistula from the outside into their sinus.
And sometimes it can be difficult. This horse, for example, obviously has penetration into the main frontal sinus cavity with with lots of soft tissue injury here. This eye was relatively swollen.
And the rim of the orbit and on the external side seemed to palpate OK, but it was very difficult to get a good look into the eye. And obviously, with this type of penetration, we were concerned about the back of the bony orbit as well. And with these types of wounds, radiographs are not particularly helpful sometimes, as there's so many overlapping structures and it's difficult to isolate them.
Certainly I think in this situation. Digital palpation is actually quite sensitive. Ultrasound can be quite sensitive looking at the bony surfaces and looking at the back of the eye.
And, if referral is an option, then often a standing head CT is optimal as it can give you all the information about both the deeper structures around the brain, but also the back of the orbit as that would need to be repaired in order to, to, save the eye if necessary. So in a case like this, I'd certainly have a good palpation around the outside of the orbit, around the, further back in the head. I'd carefully evaluate the horse for any signs of an increased amount of depression compared to what I think was appropriate for the wound, .
Try to assess whether or not it was visual in both eyes, pupilary light reflexes in both eyes, to see if there's been any disruption of the ophthalmic pathways, and, and then it can be addressed if, if all of those things seem to be OK. It can be addressed as we address any wound with debrant and the vase, and we can try to close as much as possible. Sometimes we're missing pieces of bone, but if we can either elevate pieces of bone back into place or close the skin and some subcutaneous tissue, where there's missing bone, as long as that's a small area, they tend to do quite well.
The big important things to think about are, the orbital rib fractures as I talked about. So this horse on the top right. Where the wound certainly goes into the maxi sinus, but has also fractured the orbit, at the lateral campus here, which will cause eventually cause some problems of the eye.
Again, this was an eye that you couldn't get open due to the swelling of the lids, and so we addressed the orbital fracture but had to wait for the swelling to decrease prior to being able to evaluate the eye itself. In a case like this as well, there's a simple depression of the bone into the maxo sinus which could be elevated, did not need to be repaired as once elevated back with the suturing of the soft tissues that will stay into place. And again, this horse in the middle of the picture has suffered what is probably a quite significant sharp trauma to cause this crack in the frontal sinus and then obviously has injured the back of the orbit sufficiently to cause this eye to prolapse out.
So fractures into just the sinus can be dealt with relatively carefully, but fractures involving the orbit, likely need to be assessed and if possible, they can be assessed best at a referral centre, but if not, they can be dealt with as best as possible in the field. And if there's ocular involvement, then, you know, that can be either secondarily with lots of swelling as we've seen in some of those previous cases or in this case, it's obviously, lots of tissue surrounding the eye. And the question becomes, can we save the eye or is, does it necessarily need to be removed.
Now, in that previous slide I showed you with this one that's prolapsed, that one is Obviously going to have to come out, in which case, we don't mind too much that the orbit may be fractured. We can remove the eye and then lavage and treat this involvement of the sinus, with, with lavage and then seeing if there's any of this bone that can be elevated back. But again, closure of these soft tissues will likely be sufficient to hold that bone in place.
In a case like this, it becomes more difficult to assess. This horse is likely going to lose its eye, but is it just trauma to the lid and the surrounding soft tissues, or actually, has there been trauma, to the eye itself? And I think, occasionally, initially, if there's, if the horse, is, is a bit difficult or a bit painful, this can be hard to assess.
And my inclination is always to try to save the eye if possible, but certainly if you remove it, it does make closure of the laceration considerably simpler. In a case like this, also, I'd be concerned due to the location of whether or not there would be some facial, nerve involved, and I'd be taking a close look at the symmetry of the horse's nostrils and nose, to see if there's any signs and whether that's been primarily severed in this laceration or more likely just injured with the swelling in this area. So as I said, we can palpate many of the fractures with our fingers, radiographs can be quite difficult.
Some of these more extensive lacerations can be difficult to determine normal architecture. So certainly if a horse is insured or if money is not an issue, then a CT scan at a local referral centre would be optimal as that can aid in the decision to remove the eye. If the bony support has been destroyed or aid in reconstructing the bony support to save the eye if that's deemed to be possible.
Certainly a lot of these sinus fractures, we can wire the pieces of bone together, but if they can be elevated back into position and there's soft tissue to close over top, that is actually, commonly sufficient. If there's loose pieces of completely denuded bone, then those should be removed as they will become squetrum. So, that's the case that you saw, if I can flip back, that the eye was not able to be saved.
And as you can see when you actually remove the eye, it makes closure easier cause there's less tension. I wouldn't recommend doing it just for that purpose, but I would not hesitate to do it if necessary. And even though these are often very contaminated wounds, as I said, they tend to deal with infection very well in the head.
I would put these horses on systemic antibiotics, and analgesics, but they tend to do well, in terms of if there's some underlying infection, they can deal with that without completely dehissing the wounds. If the sinus is very contaminated, then certainly this is that horse you saw with the prolapsed eye and the big gash and the eye has been removed and the, the, the bone was elevated and then the soft tissues were closed, but we left a little catheter into the sinus as it was heavily contaminated. Now some of these, while they're healing, they can leak a little bit of air, so bandaging is, is, is a good idea, otherwise the head and the neck start to balloon up with subcutaneous emphysema, but generally there's a good prognosis for these horses as long as there's not nerve damage or cranial trauma.
The last and final sort of big category of penetrating wounds is those that go into synovial structures, and these are sort of left to ask cause I think most vets are very much more comfortable because we deal with these a lot. They also tend to be slightly less dramatic wounds and then if you have a stake in the chest, and so, communications certainly are very important, but oftentimes there's some less stress and shock involved which is useful. I think the important thing is that, we really need to know our anatomy of the, the limbs to identify when a wound might be close to a joint or a tendon sheath, cause that's the first crucial step in identifying whether or not we need to look any farther.
And we know now from lots of very large retrospectives that if we can identify that synovial involvement early and early, early, I don't necessarily mean within sort of the six hour golden window of wounds or anything like that. From the textbooks, but really within the 1st 24 to 48 hours is when that synovial involvement needs to be detected and treated. So it, it is, a good prognosis with early detection, so around 80% of these horses can return to being athletic and, and survive.
Whereas if it's a week or two down the line that we notice the synovial involvement. Those horses can still do well with appropriate treatment, but it's much more of an uphill battle, and the prognosis would be more along the lines of 50 to 60% depending on the structure involved and the amount of infection. The thing that I think is great is there are some, you know, sort of golden rules about how to go about this.
And again, I think it's important to realise it sounds all very easy, but in practise, it can be quite difficult. And the, the most difficult areas that I've seen that struggle with are those involving the sheath. So the tendon sheath.
Around the fat back of the fat lock, on the inside of the hack, and the calcaneal bursa, which is actually, fairly superficial and extensive, and, and these can be difficult to identify. The one thing I will say again that some synovial penetrations can be from very small puncture wounds. So if a horse has multiple abrasions around an area.
It is useful, if possible, if the owner will let you to clip the area and make sure there's not a small but more significant puncture wound. And again, in, in textbooks in school, you'll be taught the best method, and I think the most practical method on the farm to identify if there's been synovial involvement is to place a needle under in sterile fashion into the synovial structure somewhere remotely from the wound and inject saline, and if it comes out the wound, there's communication and infection. And the reason most of these do good is probably because there's actually communication and contamination and infection hasn't actually started yet.
So if we can get in and, and, and treat the contamination, we can get these horses, to have a successful outcome. So this is just a few cases. Again, this horse has a bit of a chronic wound that was not diagnosed, but the horse would get intermittently very lame.
And in a case like this, this is very close to the calcadel bursa. Any wound that penetrates the skin in this area is at fairly high risk. And it can be quite difficult to diagnose.
And that's because it can be difficult if there's not a lot of distention, if the fluid is draining out of the wound on an intermittent or, or continuous basis. But in this horse, we placed a needle approximately here under sterile conditions into the calcaneal bursa. And distended it.
The horse was standing there, nothing would happen. And we could get quite a lot of pressure in there. And I think this is, I've seen this to be true with the digital flexor tendon sheath at the back of the fat lock as well, that you can distend it quite a lot.
And then when the horse moves, I think the tissue slides back and forth and the communication can open and fluid would then drain out the wounds. So oftentimes with the Calcaal bursa with the torsal sheath with the tendon of digital flexor tendon sheath at the back of the fetlock. I will distend them and I'll put a lot of pressure and if it comes out the wound, that's great.
If it doesn't, I'll just try to rock the horse off the limb a little bit. Just have it sort of gently flex the leg to make sure that that doesn't cause the wound to suddenly, the, the saline to start suddenly flowing out the wound. In a case like this, which is a horse that got its leg trapped in wire, certainly I'd be concerned about both the digital flexor tendon sheath, that the back of the pastor and all the way up, around the fat lock, but potentially also the pastor joint, although it's probably a little bit high for the pastor and joint, and it's quite necrotic looking.
I wouldn't sort of want to you know, have any, any needle going close to this area, but you could potentially, inject into the tendon sheath proximal to the fat lock, that's well away from the wound and see if anything exits out here at the back, of the pastern region, as that would, show that there had been communication into the tendon sheath or if, if you on, on sort of palpation, it may be close enough to the pastern joint, potentially getting a needle into the pasture joint on the medial side and seeing if any fluid comes out the lateral side. So I think these are just examples. Now, obviously, you can try to aspirate fluid and do cytology, classically in an adult horse, anything that has 80% neutrophils on the cytology would be an indication of infection, even if the cell count hasn't theoretically had time.
To get high enough, classically we say cell counts of 20 to 30 times 10 the night cells per litre would be infection, but certainly if the wound has just incurred, there may only be 5 times 10 the night cells per litre, but if they're all neutrophils, you'd start to have a strong suspicion. That requires being able to get fluid out, which is sometimes all draining out the wound and not accumulating in the stovial structure, and taking it probably back to a lab to be analysed. So certainly the injection and visualisation of saline is the most practical.
Now, sometimes that's more difficult. and, there can be other things that we can do. And certainly digital palpation, I always do.
It's not very sensitive at all, but occasionally, if you palpate and you can just stick your finger into the tendencies of the joint, then you don't need to go any farther. And, and that's quite, you know, that's, fairly obvious. But I wouldn't rely on palpation of small wounds and, and, and, and, tissue planes to identify communication with the synovial structure.
So other ways to determine involvement would be radiographs with contrast or potentially a probe. If you have a digital unit, these are great. If you don't, obviously you have to go back and develop your films, which can, can, make things a bit slower.
And I do this only after addressing the wounds, so only after I've debrided and lavaged the wound, and then prior to closure, if I have a concern, this wound close to an elbow, for example, very difficult to get a needle anywhere, distant to a wound around the elbow, but placing a probe very gently, not pushing it through fascial planes, but gentle. In this instance, that looks certainly like it was headed to the Joint. But we weren't, entirely sure based on the probe.
So injecting some contrast into there showed that it certainly involved the collateral ligament, you can see outlined there. But despite a, a good, volume of contrast entering into the wound and into sort of the penetrating pocket, none of that went into the joint and therefore we were fairly confident that the the joint was not involved. In these proximal wounds around the, the elbow or the, the shoulder or the stifle, it can be very difficult to place a needle and inject saline at an area distant to the wound.
This is another example of a big wound you can see on the radiograph, the wound at the top of the patella and placing a probe. Certainly you can touch the patella, but whether or not it penetrates into the synovial cavity was unknown. Again, contrast medium, very nicely within the wound, but doesn't, and touches the patella, as you can see, so you might be concerned, of potentially some infection getting into that, and I would treat with antibiotics for 10 to 14 days due to that finding, but there's none getting into the joint itself.
So a wound such as this, where you can't possibly sterilely place a needle into the joint, contrast into the wound can sometimes be helpful. And certainly a wound such as this would also have quite a lot of yellow serum draining from it, so that may also not be a good indication of whether or not there's joint fluid leaking out. So contrast radiographs are more useful in these proximal wounds where it may be difficult to distend the synovial structure distant to the wound.
The other crucial area is the penetrating wounds around the feet, because the feet have a lot of synovial structures very close to the outside. It's always important to think of coffin joining, which was affected in this horse with a penetrating piece of stick at the coronary band, the navicular bursa or the tendon sheath, particularly with solar injuries, such as this. Obviously, it's fantastic if you could radiograph before removing the object, cause that will tell you exactly how far it's gone and where it's gone.
Not only would I want a lateral as, as shown here, but, you know, some form of dorsal palmar, cause sometimes they can go very high, but they may be very off to the you know, medial or lateral side. But if they're anywhere close to the middle, then they can easily penetrate either into the coffin joint, the navicular bursa, or if they slide back along the heels, they can get up into the tendon sheath. So, Well, it's difficult sometimes to get there in time to radiograph before this, this nail has been removed, it is quite useful.
With the advent of standing MRI will say that once the object's been removed, if there's any doubt, A standing MRI is actually an extremely cost effective way to get to the answer, if that's a possibility for the horse and the owner. It can examine where the tract goes and whether it goes into the bursa and the coffin joint to the tendon sheath. It can also evaluate the extent of damage to the deep digital flexor tendon.
Or to the third phalanx and and that would be instead of taking multiple radiographs with contrast or trying to aspirate synovial fluid from those three structures. Once you've done all those radiographs, potentially needed contrast and aspirated 3 synovial structures, you're often at the cost of a standing MRI depending where you are in the country. I just mentioned that as it's a very been a very useful tool at a specific identification of penetration.
And that enables the appropriate treatment to be instituted early. Now, having said that penetrating synovial injuries carry a very good prognosis. Certainly, I think penetrating injuries in the foot, they're often not diagnosed as quickly as other areas, and they do tend to carry a less good prognosis, mostly because You can get rid of the infection and treat that effectively, but there's been damage to soft tissue structures such as the deep digital flexor tendon if it's penetrated into the bursa or the coffin joint, and that will obviously cause trauma to that structure and diminish the return to function.
So I the underlying key really is always knowing the anatomy of the area and what's underneath the wound, and the, the really the, the keys is to be able to diagnose what the underlying structure is and if it's involved, and then to take care of that along with the wound. And what I've hopefully tried to come across as The areas where the penetration has a good prognosis, where it maybe has a less good prognosis, and the fact that I've got a spelling mistake there, and it can be quite challenging, not only to write the word challenging, but to diagnose the penetration in some instances. And I think it's important to communicate this to owners and we try very hard to find what's been.
Penetrated within the first initial examination in the case of all of those areas we talked about the thorax, the abdomen, the head, and synovial structures, as that will improve our ability to successfully treat the horse. But sometimes it will take time and potentially advanced diagnostics, and I certainly think it's never wrong to seek a second opinion on the phone with a colleague. Or to call up a referral centre, to send x-rays or ask their advice, as, a lot of these horses, despite what are quite dramatic and significant penetrating injuries can actually have fairly good outcomes.
So that's really my talk for the evening and so I'd like to thank you for your attention and if there's any questions, I believe there's a, a board for that or something. Thanks, Yvonne. That was a really, really good talk.
Some very impressive pictures. I really was looking at some of those penetrating wounds, thinking, oh, what is the atomy under there actually? Well, I think it's very difficult when you don't deal with it every day, you don't think about it very much.
I mean, even I go and look in the books every now and again and, and try to figure out what's underneath, you know, what I'm looking at. So I think it's important not to be shy about that, really, I think. Yeah, and I think one thing that's really come across is also not to panic that those statements, I mean, I'm sure the owners will be panicking, but actually, yeah, it's really remarkable how well they actually did do from the thoracic wounds, in, in that study that you, quoted as well.
So. Yes, so certainly that's also been my experience having dealt with many of them. I think everybody is, I think it's, you know, it's, it's a little bit adrenal squeezing, you know, for the vet attending there as well.
And I think and I think they, they can go, you know, quite wrong, and the horse is very painful and, and in shock, but they can have a good outcome, and I think, I think that is, that is the, the important message really. Yeah. And and if you're worried about removing something, I mean, could you just, if you have access to it, like you saw it, so you just leaving it as a stump or was it was more trauma or does it just really depend from scenario to scenario?
No, I think it, it can be done and certainly, you know, we've we've seen several cases that one picture with the really, really long, enormous sort of fence pole thing for it. I mean that I would definitely. Definitely saw off, even if I then removed it, because I think you don't want to drag all that through the poor horse.
I mean, sort of, you know, taking the horse off the pole. So I think in those cases, you know, giving them, fairly good, sedation and, and analgesia. I mean, I think these definitely need not only an alpha 2, but some form of, opioid, if possible, would be tophenol, or a morphine and some local anaesthetic, even when you're sowing, I think the local anaesthetic in the skin around the edges does actually help.
And then trying to, to, to cut it off fairly close. And then sometimes people sort of pack around it so that if there is just a little bit protruding, but the horse, you know, sways in the trailer or does something, you know, they're hitting sort of the packing, you know, doughnut around the penetrating object as well. Yeah.
OK. So then regarding the abdominal, Penetrations. I mean, do, do you get much success with, could you just briefly mentioned one horse I think had the peritoneal lavage and all cases you get.
Success with it? Is it more hassle than it's worth or I think it, I mean, I think it's, if the owner wants to try everything and the horse, you know, is very valuable to them either emotionally or financially, that it is something that we can try, but it's something that I would go into saying this is going to be, you know, expensive to give it a try and the prognosis is not that good. So we can dump lots of money into it.
And we, we usually need to do at least we always need to do one, you know, exploratory laparotomy under general anaesthesia, but often I would say we need to do a 2nd and 3rd lavage surgically, and then sometimes you're still euthanizing, you know, at the end of that. But there are, so I would say the rare case we get out, but I'd be telling them sort of, you know, we have a 30% chance of success. Because I, I think I might have read somewhere that you could try standing person in lava, but yes, I mean, I would always leave in, you know, a chest strain and, and, and lavage them every day, so to speak.
That, that horse that I showed you actually had that, so we had a chest strain placed high in the flank and then out at the bottom and had, you know, lavages had a first surgical lavage enclosure of the large colon where it was where it was injured. And then had daily lavages, and then another surgical lavage on day 3, and then on day 6 was just a big wad of adhesions and colics. So, I, I think, like I said, I think there, there's no reason that people can't attempt it, but they have to have their eyes open before that they've got a pretty low chance of success, and it's relatively expensive.
Yeah, especially with all those surgical procedures, I guess. Yeah. And then, just one question.
So the synovial, so say joint, joint flushes, not always, cases insured. Yeah. Worth, say the owner's got owner has got limited finances, is it always worth trying to refer them to at least get one good flush on the GA or is it, could you consider just doing standing flushes out in the yard just as a cost saving exercise, or is that going to end up costing them in the long run because they always seem that they get so far then they'll go.
Yeah, I think that's a great question because I think . That probably in the past we've sort of kept them in the hospitals really long times. We've, you know, done lots and lots of antibiotics, and there are a lot of horses who could probably have an an arthroscopic lava, or big cannulas, lots of flushing under under GA and go home the next day.
And if it works, it works, and if it doesn't, it doesn't. So I think what I would, but what I would say is that if we is absolutely not an option. So they don't have any money.
You know, there's, I think they'd sort of be sort of, you know, 3, you know, grades of treatment. I would, I would give it a try with a, with a needle flush on the farm, because some of them just have a small amount of contamination, and will actually survive and do well. And as, as long as the owner knows that if you try that, and then in 5 days' time, they're non-weight brain from a massive synovial infection, you have to stop.
That's, that's OK. Or they can have, you know, a very quick lavage and go home quickly, or they can sort of have the gold standard of staying in the hospital and having regional limb profusions and that sort of thing. But I personally wouldn't necessarily euthanize them on day one if referral wasn't an option because some of them are just a contamination.
The thing that I would warn against, which is impossible to guard against, but I think talking with the owner on day one, they say referral is not an option, and you say, I'll give it a lava. We can get you can get a litre or 2 litres on the farm with needles. And then on day 5, it's no weight bearing from synovial sepsis, and they say, well, actually, now we want to refer it.
And, and obviously that, that case will happen because we can't always, you know, con convince people. But that case. Has a much less good prognosis than if they referred on day one.
So, I think we, we just have to try our hardest. And obviously, you know, that case, you know, would still get referred and treated, but it would just be a shame that it had waited that long. Yeah, when, yeah, when push comes to shove, they possibly would have gone for the referral, I guess in the first place.
Yeah, I think it was a chance as well. I think that's the hard part is that sometimes you you explain all you like, and they don't pay attention, but Oh, brilliant. So that's, all the questions this evening.
So I'd like to thank, everybody listening, and also, a huge thank you to you, Yvonne for a really interesting talk, and really, really clear as well, and some great diagrams in that or pictures actually as well. So thank you very much. Great, thank you.
Bye bye. Bye bye.
