So thank you. I'm pleased to introduce my subject for today, which is managing complicated claw horn lesions. My name is Owen Atkinson.
From Dairy Veterinary Consultancy, and I hope you enjoy what I'm about to share. So what we're going to cover, we're going to cover classifying the main lesions of the bovine foot. That cause lameness.
We're going to look at managing difficult dermatitis lesions briefly before moving on to treatment of infected clawhorn lesions. Then we're starting with infected Clawhorn lesions. We're looking now at complicated lesions, complicated claw horn lesions, which is the topic of today, followed by a few words about distal interphalangeal joint infection.
That's the, the joint between P2 and P3, and that is quite a difficult one to,, To treat and the treatment of my choice is digit amputation, so we will look at that. And then we'll return back to to necrosis and look for alternatives apart from digit amputation, digit sparing techniques for that. So we're going to start by looking at the lesion types, and there are two broad lesion types infectious lesions and noninfectious.
We're going to start with the infectious lesions. So these are skin lesions in effect. The most common by far and the most common lesion causing lameness, at least in our UK dairy cows, is digital dermatitis.
This is a bacterial infection. It's an infection of the skin. It is caused by a group of bacteria going under the name of treponemes.
And this photograph shows two different types of digital dermatitis where the red lesion is an active type that's classified as an M2. Don't worry too much about these M classifications. It's not the purpose of today's webinar.
The M2 is an active lesion that's at least 2 centimetres diameter, and then this horseshoe lesion underneath, which is darker and almost like a scab, would be classified as an M3, so it's a dormant or healed lesion which would be non-painful to the touch. It's not usual actually to find an M2 and an M3 on the same foot in this way, but it's a nice photograph because it does show that. Looking at some more examples, this would be an M2 lesion, very active, more than 2 centimetres, very, very painful.
And again, M2, active, more than 2 centimetres, very, very painful to the touch. And again, M2. Look here where my arrow is active, more than 2 centimetres, painful to the touch.
Now what I've shown you is the usual site for digital dermatitis. It also occurs in different regions of the foot, and here it's on the front of the coronary band, and this one's a crusty lesion. It would depend whether it's painful to the touch or not, how you classify it, but if it was, if it was totally healed, you might call it an M3.
I suspect if you just, if you just, perhaps, gently remove some of the crust with a cotton wool. Or a swab, you'd find actually that parts of it are active, so that would be classified as an M4 plus 1 lesion. So an M4 is a chronic lesion and then the plus 1 would be where it started to become more active around the edges or perhaps parts in the middle.
Now this photograph shows two different infectious skin. Lesions. One is dal dermatitis.
It's more chronic form because it's a little bit, cauliflower-like. And it would still class as an M2 if it's painful to the touch, which I suspect this one would be. And the second lesion here that I'd like to draw your attention to is heel horn erosion, which is what it says on the tin.
It's where the horn has erosions, so quite deep crevices sometimes, and this is caused by our second type of bacteria that I'll introduce you to. And it is Diylobacternodosis. I used to know this as Bacteroidesnodosis.
It's changed its name. It's now Dylobacternodosis. Generally speaking, it's non-pay for its own right, but it does erode valuable.
A weight bearing surface and it is associated with other types of lameness such as soul bruising and so ulcers, probably because it erodes valuable weight bearing surface and it's also highly associated with digital dermatitis, probably because the risk factors for both types of disease are similar rather than necessarily being that one directly causes the other. But that's he hole erosion, our second type of lesion. Back to some digital dermatitis.
We've got a very, a hairy wart version here, a very chronic one. And this, if it's not painful, will be an M4 chronic, not painful. If it's still painful, it will be an M2.
I suspect it would be painful again if you rubbed it with a cotton wool. I imagine it'd be very red sore still and painful, so M2. And then on the right, this is a digital dermatitis very early lesion.
Now because it's less than 12 centimetres in diameter, you classify this as M1. So if I just run through those M classifications again just as a recap, M0 is healthy skin. M1 is as you see on the picture on the right here, a very small active lesion, less than 2 centimetres.
It's an early start. And M2 is like the ones I've mostly shown, which is active, painful, more than 2 centimetres. And M3 is a healed scab.
Basically an M2 that's healed, so it's crossed and non-painful, and an M4 is a chronic. Ferricose, i.e., proliferative, but non-painful lesion, and an M4 + 1 is one that has started to recrudece as in it's, it's got an active painful element to it.
So that's the M4 +1. So these, those lesion types can be quite complicated to remember. Don't worry about it.
It isn't the focus of today. Just really saying that digital dermatitis can look very different going through these cycles of different lesion types. So different or different cows.
Digital dermatitis again now in this case this heifer was actually a BVD PI animal persistently infected animal, and that she had very active painful digital dermatitis on all 4 ft. And it illustrates how the, how this is a complex disease that doesn't just involve the presence of the treponemes but also other factors such as in this case an immunosuppressed animal. So the immunity that the animal has will very much govern to what extent the lesion becomes active, and there are all sorts of other aspects, including genetics that determines whether or not a cow gets an active clinical lesion.
Now we move on to our third bacterial type, and this is foul of the foot, and this is caused by a fusiformumcopherum in America. This is called foot rot. It's very similar also to foot rot in sheep.
So this is where in between the toes, it has a very classic foot rot smell. Most of us would know what that is like. It's a foul smell.
It's you have to have an abrasion or cut between the skin to allow the bacteria to get hold, so you can get little outbreaks of this. Sometimes when one cow in the herd gets it, or perhaps one in a group of young stock animals gets the infection and then it spreads between animal to animal, perhaps through straw or through stony gateways or, or wet, muddy and stony areas around a water trough where it'll spread because of abrasions to the skin. When a foul is left untreated, it will often proliferate, and this is where you get an interdigital growth.
So interdigital growths are very much associated with foul that hasn't been treated promptly enough. What this photograph shows is, is an interdigital growth with digital dermatitis lesion on it. It's an M2 active more than 2 centimetres, and it will be the digital dermatitis on this cow that will be giving the pain rather than the digital growth.
So in summary, our non-infectious, our skin lesions, are digital dermatitis caused by trepones, foul caused by Fusobacterium necrophram, heel horn erosion caused by diclobacteridosis. Move on to 2nd lesion type, claw horn lesions. Now these are noninfectious.
The most common is soul bruising, and this is the most common site for soul bruising. Don't, it's, it's red or yellow horn when the horn is trimmed, and don't confuse it with these black areas, which is normal pigment. And incidentally, this cow also has digital dermatitis.
This would be an active M2 lesion here on the back of the heel on the skin. Not unusual to find lame cows have got more than one reason for their lameness. A sole bruise in that area in that region, if it is left untreated, may well develop into a soul ulcer.
So a soul ulcer is a more severe form of sole haemorrhage or sole bruise. And let me show you with this slide what we're talking about. Again, this, this presentation is not about the aetiology of claw horn lesions.
We're looking at the treatment of complicated ones, so I'm very can be very brief about this, but essentially soul bruising, so haemorrhage and soul ulcers are caused by a pressure point on the back of the foetal bone here, damaging the corum here, which is responsible for producing the sole horn here, and you can see here actually there would have been a defect in sole horn production. And at some point in time, probably about 3 weeks ago, judging by the amount of the distance from the corrium to that lesion. And that's what soul bruising is.
It's pressure. It's pressure and inflammation. Whereas where I showed you just now is the most typical site for cell bruising, so haemorrhage, and indeed cell ulcers that's where the site is because it's a natural pressure point.
We can also get so bruising in different areas, and this is an atypical example. And the sole bruising here is near the toe and it is due to thin soles. So this is an example of something you might see in grazing farms, grazing herds.
This cow, in fact, the photograph I took when I was travelling in New Zealand. And lifting cows' feet there that were lame, it was quite a common finding the lesions, the sole bruising, so haemorrhage in towards the toe area and touching the sole, it would almost be paper thin. You could really dent the sole with your thumb.
So the damage is still damage to the corum due to pressure. But it's not so much the pressure of the pedal bone pressing down from above, it's more the pressure of the rough surface, floor surface pressing from below, given this thin sole. Here's an example of another, if you like, atypical soul bruising, because it's across the whole of the soul of both the inner and the outer digit on a bull, and this is a young limousine bull.
I took the photograph some years ago. He had just been introduced into a herd of heifers. He had been introduced onto concrete for the first time, and after a week of having a lot of fun with the heifers, he had very, very thin soles.
They'd worn very thin. Again, if you touched them, they were. You press him with the thumb and and, and very shortly afterwards, he developed this bruising.
This Cow has, has quite a nasty sole bruise here, pigment here. She also has a An ulcer here on the outer claw. This is their inner claw, and this is the outer claw.
It tends to be on the hind feet tends to be the outer claw that's most severely affected, and I hope you can see from this slide that actually a soul ulcer is just a more severe form of soul bruise. She also has a toe ulcer. This cow is a cow from New Zealand who in the, In their autumn, having been exposed to wet tracks for quite a long time, had very, very thin soles, walking quite long distances, and essentially just worn her soul away and then had this ulcer and ulcer soul ulcer, toe ulcer, and so bruise.
So we've done so haemorrhage, we've done soul ulcer. We move on to the third of the main Claw horn diseases, and this is white line disease. It's very difficult to get a photograph to just just depict exactly white line disease because again there's a lot of variation between between different cows on how it looks, but essentially it's separation of the white line here.
Sometimes whiteyme disease can be used just to describe severe bruising on the white line. But often that bruising is a little bit more than that, and there's a grit that's, that's worked its way in through the separated white line, that grit or dirt or bacteria has found its way to the chum, i.e.
The live tissue. An abscess is formed and then it becomes a white line abscess, but it's all under the same bracket as white line disease. Essentially, and a very rough rule of thumb.
Soul bruising, like I've shown you in the previous pictures and soul ulcer, is to do with a compressive force on the foot. So the classic soul also society is where I showed you towards the back of the pedal bone, and that's due to the pedal bone pressing down on the corum. White line disease is more associated with shearing forces, sideways forces of the foot.
So whereas so bruising and soul ulcers in the classic area might be associated with long standing times, for example, pressure. Just pressure through to standing, which you might see with very poor cow comfort, overstocking, not very comfortable cubicles. White line disease, which is more associated with shearing forces, is more associated with poor cow flow.
Now that could be due to overcrowding again, pushing and shoving. It could be due to stockmanship. In other words, pushing the cows together, forcing them as the, as you, as, as the stock person is herding them, so they're pushing and shoving and jostling.
There's also other factors such as floor surface, which can be a big influence. Essentially, wherever you hear cows skidding or slipping or sliding, think white line disease. As I said, white line Z is often associated with the white line abscess, where, whereas, whereas damage to the white line might just initially be a haemorrhage, that white line can separate.
It allows bacteria to get into the corum or the lamina, which are between the wall and the pedal bone, and then an abscess begins a little bit like if you imagine getting a thorn under your thumbnail or fingernail, you get a very painful abscess, and that's a white line disease. Or white line abscess, I beg your pardon. Now the pulse within this solid hoof capsule builds up pressure.
And so it kind of finds a way to go. It'll take the, it'll take the route of least resistance, and that's one of two ways. It either tracks up the lamin on the inside of the wall and bursts out of the coronary band like I believe this has here.
That little bit of white pus where my arrow is will be where the infection, the pus, the abscesses burst out to the coronary band, so it tracks up on the inner wall like that, or Oh sorry, let's just show this is one that's been trimmed away, so it would have started here and it's tracked back, back, back, and it would have burst out of the band. Or that pus will track and underrun the soul to burst out at the heel. And here's the white line, abscess, which is dirt.
So it's it's the white line lesion, sorry, the abscesses beneath this dirt, so the impact of dirt from the white line that's separated, and the pus has burst out at the heel here. Now where that probe is, the, the, this blunt screwdriver, which I have used to demonstrate this, it hasn't been driven into a healthy hoof. It is literally just put there for the purpose of the photograph to show how the, the soul has separated, to.
To to allow basically the puss to escape. So white line abscesses like this that burst out of the heel, often people call them underrun soles. They're not really underrun soles.
It's just where it's a white line abscess that's burst out of the heel. And to correct that, it's just a matter of removing the overlying horn and And if it is drained already, then it's a very simple procedure to treat a white line abscess like this. So this is the same foot.
The one on the left is pre-trimming, the one on the on the right is after trimming. And it's blocked So in summary, we have 3 main non-infectious lesions or Clawhorn lesions so haemorrhage, so ulcer, white line disease. So haemorrhage and cell ulcer are kind of essentially the same disease, but, different degrees of severity.
Taking those three diseases, the effective treatment. Is a very similar approach. So effective treatment of claw horned lesions includes take the weight off where the lesion is that allows healthy horn to be replaced and for it to heal.
If that can't be done by trimming alone, which often it can't, then take more weight off and use a block on the on the partner digit. And then third, importantly, and this is a this is a I guess, I guess a more recent improvement in our knowledge and understanding. Is to use an anti-inflammatory, a non-steroidal anti-inflammatory, and use that early on.
And the reasons are quite complex, but they include the fact that, you don't get bony changes on the foetal bone, which are non-reversible. And meaning that that cow will have a, for example, a soul ulcer have a tendency to get a soul ulcer again and again and again. So it's the early use of non-steroidals using a very, very early stage of these disease processes that are important.
So take the weight off using trimming, add a block on to take more weight off and use non-steroidal anti-inflammatories early on. So now we're getting into the knob of, of, of the presentation, which is looking now at some more complicated lesions. And these are, I'm going to start with infected claw horn lesions, and the infection is with digital dermatitis reponemes.
And As I've, the ones I've shown you before have been non-infected examples of white line disease or soul ulcer, where just using those three principles of taking the weight off with a trim, taking more weight off by using a block, and using non-steroidal anti-inflammatories is enough to effect a cure, and you would normally expect a good speedy cure. Unfortunately, in the last 20 or 30 years, basically in my working lifetime, we have found that often doing those three steps isn't enough because this dermatitis treponemes are so prevalent on our on our farms that the treponemes, once they get into the corum, which is the soft tissue, the live soft tissue underneath the horn, the claw horn. Those treponemes or that infection prevents the corum from producing new horn, new healthy horn.
So we end up with a non-healing claw horn lesion. So non-healing claw horn lesions are ones where The corum, the soft tissue, the live tissue underneath the horn has become infected with primarily treponemes, but they assume that it will be a mixed infection of different bacteria, but it's the treponemes that seem to be the ones that cause the the big issue or maybe the gateway for other bacteria to get in. And they prevent any healing.
So here you can see hopefully additional dermatitis lesion. It looks like dermatitis. It'd be an M2 lesion on the coronary band where a white line abscess has drained out at the top.
That would have caused an exposure of the soft tissue, the corum at that point underneath the coronary band. That's become effective with treponemes, and there is no way that this is going to heal unless we do something different. So these become very chronic lesions and we lose a lot of cows with these kind of non-healing claw horn lesions.
It's a problem. I've been told by colleagues that work in New Zealand that they don't see that to this degree. So digital dermatitis does appear in New Zealand herds, but much much lower prevalence.
And so their treatment of white Lyme disease is very simple. They just have to go through those steps, you know, they remove the, the, the horn, they take the weight off, they give a nonsteroidal, and they get better. If only that was so true for us, and it is largely not because we get these trepoines that cause secondary infection.
And sometimes a secondary infection can be very obvious and chronic as you see here. So this should be a chronic varicose form of dermatitis, but the original lesion was a white line, the white line abscess, but the digital dermatitis got into the corum and, and caused those kind of varicose lesions like you'd normally see on the, on the, on the skin, and there is no way that it is going to heal. Not unless we do something more radical.
And again, a soul ulcer in this case, a soul ulcer that has got treponemes on top of it and it looks and it smells like this dermatitis, and these are incredibly painful to the touch, incredibly painful to the touch. And what I've tried to show with the right hand diagram now is kind of what's happened. So we've had an original Soulal site which is marked by the yellow dot.
That has become infected as they sometimes do. And so Pus has underrun the soul and caused a fault soul. In most areas, there has been new fresh soil being produced, so these white areas here, and, a false soil above it.
But unfortunately, So sorry, so the abscess would have burst out of the heel, the back of the where the bee is the bulb of the heel where it's burst. That's allowed tissue dermatitis to ingress, those trepones to ingress presumably, and, and infect, the exposed corum of the cell ulcer, and then that now prevents the healing. Or indeed allows for greater buildup of pus.
I don't know the order, but in, in, in essence, we've got a soul ulcer that has been sarily affected with its trappones and it has become a non-healing claw horn lesion. And again, very similar again. It looks like a very severe foot, but that's because I have removed the under, so the overlying horn, which is not firmly attached, and this dis dermatitis lesion is, is obvious underneath there.
So to have a chance of these healing, we need to have a slightly different approach. So yes, we remove weight off the lesion and we use blocks liberally on the partner claw to allow that to be more effective. But we also need to be very, very careful that we remove all unattached horns to the point of firm attachment.
Now this is the bit that if I was a vet working in New Zealand, I probably wouldn't need to worry about quite so much because they don't get these secondary treponemes. If we leave unattached horns, so these are loose horn that has been underrun by infection by pus. And therefore it is now no longer firmly attached to the underlying lamina or the corum.
If we leave that, then we don't expose the reponemes to the air, oxygen. They tend to fester and we just don't get a healing. So we need to remove all unattached on to the point of firm attachment to remove these pockets, these anaerobic pockets.
Now whilst doing this, we also want to avoid bleeding because if we're getting bleeding, we can't see what we're doing. That's very critical, but we're also causing more damage to healthy tissue which we don't want to do and it's also painful, although I would recommend that if we're doing very difficult lesions like the one I've shown you prior, and we want to be using. And intravenous regional anaesthesia for welfare reasons, and it makes the trimming a lot easier and safer too.
But we want to avoid bleeding where we can. Now it's not always possible to 100% avoid bleeding. The photographs before you would see there was blood, but the principle is to try and avoid bleeding.
Then we want to treat the digital dermatitis. Now to treat the digital dermatitis, my strong recommendation is to use a licenced product and no bandage. I'm not a fan of putting bandages on because I believe that it, it, it maintains a very moist and anaerobic environment which is dermatitis love.
So if we avoid bleeding, There is no reason in my view to put a bandage on, and we can use a licenced. And treatment treatment such as oxytetracycline spray, blue spray. Now it does work.
It'll need reapplying on perhaps day 23, and 4, but it does work. It will treat those dig dermatitis lesions. Don't go off label.
Don't start using powders that are antibiotic powders that are not licenced for this. There is no reason to. There's absolutely no need to at all.
There are, or there is one, licenced selated copper product which is no antibiotic which can also be used and is effective. There are 2 licenced antibiotics in, in the UK or two types, sorry, two families. One is oxtrocycline and the other is, thiaminicol.
Which is, is useful for those that aren't responding to cycling. There is, there is a slight variation amongst the different repones to their degree of sensitivity to those different antibiotics, but . Time to call is an alternative to tetracycling which can be useful.
And then finally use nonid anti-inflammatories again and use them early on, and that prevents inflammation causing Permanent bony changes or even permanent soft tissue changes, which means that their cow will become lame again and again after the initial treatment. So if I show you an example, now in this case, this is it's a white line abscess right at the toe, and you may call this a toe also for that reason. It's a nasty looking foot, so it looks at the beginning like the one on the left where, you know, we've got a little pocket of pus and it smells, and by very carefully trimming away all of the unattached horn, I found that actually the there were several layers of underrun sole.
Where it is healed a little bit and then it's flared up again here a little bit and flared up again, and that leads to sometimes more than one layer of underrun sole. So I've removed all that to the point of firm attachment, and the point of firm attachment what I'm talking about is all around the edges here where there is no more pockets or underrunning of soul. So on some cows you'd actually remove all of this as well if it was under runway, you can see where my arrow is here, if this is underrun, then you would remove it.
But this is the point of firm attachment and it's a careful and painstaking job to do this. Principle number 3 is to avoid bleeding to the extent that I have been able to, but you can see that there is bleeding because you're working right on the edge of the healthy, of the healthy tissue, it, it's almost inevitable that, there is some bleeding. I used dry cotton wool to try and dab that bleeding away so I can see where I'm going.
And this be in no doubt, this treatment was done under regional anaesthesia, intravenous regional anaesthesia. It is not acceptable to be doing this type of, of, of radical resection or curettage, without using, a, a nerve block. From a welfare point of view and also because it is safer and because the cow's foot will stay still and it will therefore be a lot easier to do it.
So the following parts would be now to block the the part of the claw. This would have a block on it to raise it. This would be sprayed liberally with oxy tetracycline spray and unless it was bleeding more severely, I wouldn't put a bandage on.
If it was bleeding a lot, I would put a bandage on and with a bit of cotton wool and the blue spray underneath it and and or the antibiotic spray, and that bandage would stay on for 24 hours maximum, maximum. Now that's my approach. And that's for the reasons I've explained, because I feel that we use bandages too often with dermatitis lesions, which in my opinion, leads to moist anaerobic conditions and a recrudescence of the infection because this dermatitis likes those conditions.
So a second example, very similar in this case it is, it is a toe ulcer, which arguably you could say is a white line abscess of the toe. So it'd be a very, very acutely painful cow because they are these conditions are very, very acutely painful. And you can imagine finding the point of pain with the hoof testers.
And then I would use, sorry, then I would carefully investigate the black spot there was. You get a release, immediate release of pus and pressure, and you can see that in the left hand picture with little gas bubbles there bubbling away, and you can always sense the relief of the cow when you do this, when you release, release those really tight, high pressure abscesses and particularly in the toe where they're very painful. Now at that point, I would do a regional anaesthesia.
IVRA, and I would wait for 10 or 15 minutes while that worked, and that's a good opportunity to block the the partner photo. It looks like I left the blocking until later on in this case, but you could block the partner for and get that bit out of the way and then come back to the painful lesion. And this is where you need to again very carefully curate any underrun horn or horn that is not firmly attached to the underlying tissues, wherever that takes you, wherever it takes you, and in this case, it takes us quite a long way back on the medial aspect of this foot.
Sorry, not the medial aspect, it's the, the axial aspect of this foot. And it looks almost as if it was about to burst out between the between the toes here at the coronary band at the back here. It hadn't yet burst out, but if we'd left it, it might have done.
Now again, what I would like to think you can see here is how this underlying corium has become infected with treponemes. It looks and it smells like digital dermatitis. I didn't swab this and I didn't confirm that diagnosis, but I kind of I accept that that's what the researchers told us is that these non-healing lesions have usually got repodine infections or trapodine burdens associated with them.
That work was done at Liverpool University some years ago now. I'm thinking 15 years ago, possibly, where these non-healing claw horn lesions have been associated with treponemes, but you get this, this look of dis dermatitis, and unless that is adequately treated. It won't heal.
Now what I've used here is some talcum powder actually just to dry that out and then that will be followed by some chloro tetracycling spray or tetracycling spray, and, and not a bandage, and that will be the complete treatment. Now, sometimes it is not possible to, resect the foot. Enough because the degree of underrunning or the chronic nature of those trepone infections are just too severe, and this is an example.
This is a claw that has clearly been amputated because there was not a more conservative approach, but it would have started with a white line lesion. These tireponemes have infected the corrim or the lamina underneath, and if you open this, this is the same foot, but if you open it up, you can see that chronic varicose infection and the degree and extent of chronic infection there was just such that there was no way that you could remove the tissue and yet be left with a hoof that had a chance of repair, and I would believe that these varicose trepoine infections on the, on the corum here would not be, it wouldn't be treatable, would not be treatable. And so digit amputation would be a course of action if this cow is to be salvaged.
And from a welfare point of view, this is not nice to see because the cow would have been in chronic pain for quite some time, and months, I suspect, where the farmer has been battling away with what started as a white line abscess. It hasn't healed. It's become More and more difficult to treat as time goes on as those treponem infections become more embedded and Hence turning to myself as a vet and doing a digit amputation.
And the same again you can see how how severe that hoof is. This is one of the most severe ones I've ever seen in practise, hence the photographs. I'm going to return to this area a little bit when I look at necrotic toes because tone necrosis is very similar to what I've explained, but I'm going to turn away now to something quite different, which is the distal interphalangeal joint infection.
So just leave digital dermatitis to one side now. This is nothing to do with digital dermatitis and nothing to do with trepodines. We're moving on to a different type of complicated claw horn lesion.
And this is the distal interphalangeal joint infection. Now, just as by way of anecdote, I don't see these half as often as I used to when I was a younger vet in practise. And, when I was a younger vet in practise, and, and I qualified in 1994.
Nearly all of the digit amputations that I would have been doing in those days would have been for a distalinphalangeal joint infection, and a farmer might know this colloquially as a club foot. So here is a cow here who's lay on her back left and she has a club foot. This is the same cow, same foot.
So Chronically swollen. It's unilateral. It's, it's on her, lateral claw.
This is a different cow, different foot, but it's showing exactly the same thing, a chronically swollen, unilaterally swollen foot now. So the casual observer, you may confuse these grossly swollen feet with, with fowl, and a farmer may well be treating her with systemic antibiotics as you would treat a fowl, but are totally barking up the wrong tree, because actually what's happened here is it's, it will have begun as a soul ulcer, usually they've begun as soul ulcers. They have become infected into the joint space.
Once you get infection into the joint space, you're on a, you're on a. A road to nowhere. And a more radical treatment is required.
Those cows will not respond to antibiotics. Now how do you know it's in the joint space? How do you know that interfas the joint space?
There's a couple of giveaways. So as I say, it starts with a, with a, with a soul ulcer. The sole also becomes effective.
I'll show you a picture in a cross section to show you how close those souls are to the distinalangeal joint space. The, the, they are usually associated with a, a ruptured, flexor tendon. The flex tendon inserts on the, on the caudal part of the, P3, the pedal bone, and that because of the infection has ruptured.
So you get a cocked up toe, what I call a cocked up toe, What should I call this, to be more technical. It's an extended toe, not flexed, it's an extended toe, because if the flexor tendon is, is, is, is ruptured, then it tends to cock up. That's what I mean.
So I hope you can appreciate what I mean by that. The toe points here on the effect on the affected claw is pointing upwards. But the second thing you see is if you squeeze on the bulb of the heel here and at the same time flex the toe, which is squeezing that joint space, you see.
A little bead of pus come out of a sinus here, and the sinus is in the middle of the cell ulcer site, and that is the giveaway to me that that infection is in the joint space. So if I see those two things, 3 things if you like, unilateral swelling in a painful cow and a Extended toe cocked up toe and puss in the coming out of a sinus in the middle of the the sole also when I squeeze the heel and when I flex the toe and I squeeze that joint space, then I know that that cow has got an infected. In digital joint and the best treatment in my view for those is digit amputation, and I say that with experience of trying some what's called a more conservative approaches digit or digit sparing approaches and they're not conservative, they're quite radical actually, but digit sparing approach.
And I no longer offer digit sparing approaches as an alternative because I believe in my opinion and in my experience they cause unnecessary extended periods of pain for the cow and yes it is possible to preserve the digit, but for what purpose? Because that digit is, is, is, is a functionally non useful digit. And so I would, if the cow is to be retained in the herd at all and not cold through welfare reasons, then I would always opt for a digit amputation for these cases.
So again, what we can see here is a sinus and a bead of pus coming out of that hole. So when you see that, Think this. So you can see here how the soul site is very close to this joint space here.
This is the ruptured flexor tendon that we see here, this white thing is ruptured, so you can imagine how the toe gets cocked up. And once you're getting a bead of pus coming out of this space here, which will be coming from this joint space here, and this is, we can say this is confidence because there's a lot of swelling around the carary band all the way around the hoof, then we're looking really at Doing an amputation. Once you've got infection here in this joint space, There is no way that that will heal by You could give her a bucket load of antibiotics, and this will not heal.
You do need to do something radical, so it's either a radical resection to open up the joint space, which is the digit sparing techniques, which I'm saying, in my opinion, are not, are not valid. That's my opinion, or we do digit amputation. Now less frequently, those deep sepsis, joint sepsis can stem from a white line infection.
A white line disease has become affected because that's another route into that joint space. But again, you would see, you don't necessarily see the The extended toe in the same way, but you see that bead of pus coming out of the sinus. If you squeeze the bulb of the heel whilst flexing the toe, that squeezes the joint space, you see a white bead of pus coming out of the middle of a joint space here.
And if you're seeing that, you need to do something quite serious because that hoof is that foot is not going to recover by doing anything different. And again, a digit amputation would be what I would recommend. So let's look at digit amputation.
There are 3 essential techniques for digit amputation. 123. So number one is cutting using an embryotomy wire through distal P1.
This is P1, P2, P3. Number 2, I And the bleak cut using, so we're sticking with the cutting at the moment, using a embryotomy wire through. It's either proximal or mid P2.
In effect, it's usually mid P2. It can be proximal P2. Just getting the angle.
And number 3 is X articulation. So this would be not using embryotomywire. This is using a scalpel blade and, and careful dissecting to dissect away between P1 and P2.
So that would be my, method number 3X articulation through proximal interphalangeal joint. So the infection is in the distalinphalangeal joint. We're talking about X articulation through proximal interphalangeal joint.
Now, my preferred, method will be #1, distal third proximal phalanx, and there are reasons for that, quite distinct reasons. Firstly, it's very quick, so that, well, I'll go through the reasons why I don't use the others. The ex-articulation is quite figly, it's quite slow.
It's quite difficult to keep a, a clean, operating site on, in, in on-farm, conditions. And in addition to that, once you have This articulated the P2 from P1 you then left with a very shiny joint surface at the disc. It's part of P1.
I hope you can appreciate that. If you've removed P2 and you just leave the cartilage exposed, that's a very shiny joint surface. That won't heal over.
It won't granulate over because of that cartilage on the, on the exposed P1. So in order for it to gra granulate over, you then need to remove the cartilage, and that's very, very difficult to do with the scalpel blade. It's the sort of thing where you might end up hurting yourself.
But in any case, it's just very, very difficult to do and fiddly and it's. Given on-farm conditions are far from ideal, it's difficult to stop gross infection. So that's the reason why I don't prefer the X articulation method.
It's, it's, it's largely. Convenience, but also that sort of clinical reason that if you don't remove the cartilage, you don't get granulation. Now the reason why I would exclude method number 2, which is the oblique cut through second phalanx P2, and by the way, in my experience, this is what most vets do.
They don't really know where that root wire is going. So if you're just someone who, who does digit amputations and you haven't really thought about this too carefully and you just tend to say, well, yeah, I put the embryotic wire between the toes and I get a sharp angle, I give it a good, a good . Quick cut, then you'll probably do method number 2, which is your, your cut is probably going through, P2.
Now, if you go through P2, you have to think about what's left behind. What you've left behind is the proximal part of P2. It'll granulate over, not a problem, because you haven't left exposed cartilage, but the problem comes in that because you've gone through the middle of P2, you've essentially disrupted the blood supply for that bone.
So that bone will They undergo ischemic necrosis. The bit of bone you've left in, the bit of P2 that you've left in the cow, will undergo ischemic necrosis. It will eventually slough off.
When it sloughs off, you're then exposed, you're then left with the exposed cartilage on P1. And so what you get and and for people who are struggling with digit amputations, when, when I speak to them, I often find that This is the reason why they say, oh, I don't do the amputations. They don't work.
Well, the reason why they are not working is because they are going through P2, not P1. The proximal part of P1's left in the cow. Undergoes this chemic necrosis.
It sloughs away. It leaves cartilage on P1, which then doesn't grind that over, and you end up with a digit amputation that doesn't doesn't heal, or if it heals, it heals after months and months and months, and that's not what you're looking for. You're looking for a much speedier recovery than that, and that is why the method that I'm recommending to you is cut through distal P1.
You're not disrupting the blood supply of the bone here, P1 by just cutting through that that distal part. You have removed the cartilage. It allows granulation, so you get a healing, and then the skin will grow over that.
So let's look at what we're doing. Well, there we are. That's another photograph of what I'm recommending.
It's that embryotomy cut embryot cut through distal P1. How do you achieve that? Well, you do need to consciously cut vertically, and make a vertical incision between the digits in order to get high enough to go through distant P1.
If you're not cutting 2.5 centimetres, Well, I've put 3 centimetres dorsally, 2.5 centimetres on the planter aspect.
It's very similar, an inch or so with a scalpel blade before you thread your embryotomy wire in, and then even so going at an oblique angle, if you're not making that at least 1 inch incision between the two digits before threading the Embryotomy wire, then I'm afraid you're going to be going through P2, not P1. The level at which you're cutting is around is just is just level with the bottom of the dewclaw. So hopefully you can see some pictures here which sort of shows the process.
So you're making a decision between the claws front and back, approximately I put 45 centimetres deep there and With the scalpel blade, you then thread the embryotomy wire in. There's no reason to go overboard on the surgical hygiene. You can see on this.
It's just it has been cleaned up. I've used surgical spirit to clean between the toes to get rid of the gross infection, but because we're not really handling the tissue too much, it, it, it, it's OK. .
Thread the embryotomy wire in, then go slightly oblique so you can see that the cut is starting about level with the dewclaw here, goes slightly oblique, not massively oblique, but slightly oblique, and then that will be going through. Distal P1 and this is what you end up looking like, and you should be able to with your finger, you should be able to wobble, so if you, if you try and wobble the bone that's left the P1, there won't be a wobble because you, the P1 is quite a big bone. If you've got a wobble, it's because you've gone through P2 and what you're wobbling is the proximal part of P2 that you've left behind.
So the, the downside of this, and this is where it does get difficult with managing these, is that you end up with a very awkward shaped wound because it's L shaped rather than if you've just gone oblique through P2, you, you don't end up with this L-shaped wound. Now that does make it harder to dress. I'm not going to go too much into the detail of that because of time, but it needs to be packed well, when you put your dressing on and the dressing is for hemostasis, obviously.
And You need to put a good fist-sized wad of cotton wool and Over a no nonadherent wound dressing and then that allows you to apply, apply a reasonable amount of pressure with the, the 2nd and 3rd layers of bandage for hemostasis. So yes, dressing those lesions is quite difficult because of that awkward L-shaped wound. So this is that same cow.
She's still got her IVRA, so she's still got a numb foot. The painkiller will be perfectly effective until that wears off. So we're using non-steroid anti-inflammatories as painkillers longer term.
And just as a tip, I would advise you to return these cows to the herd, not that they're walking a long way or going through muddy gateways, etc. This is dry mud. And so it's just about acceptable, but in my experience, keeping these cows in isolation, particularly on deep straw, can almost be the worst thing for them because they, they don't stand up, they don't exercise, they sulk, and I think that leads to delayed healing and more likely swelling of the foot.
And in fact more pain. So just as a tip, I would return to the herd and be very wary about keeping on deep straw beds. I would avoid deep straw beds for healing.
I won't go into the details of the of the management of the of the wound dressing. I'll show you resources where to go to look at that in more detail. What you should see is that 6 to 8 weeks later that is.
Healed over, new skin. Cured and this is what you should be expecting to see. Going back some years, and we did a case studies or a series of case studies in our practise, and we looked at 110 cases of pair matched digit amputations.
So this is digit amputation cases matched with a control within the same herd, and we found that 89% of cases were still in the herd at day 100 versus 95% of the controls, and after one year, 54% of cases from the herd versus 60% of the controls. So the survival isn't as good as. As if they hadn't had a digital amputation, but it's pretty, it's pretty high up there.
So it's not a salvage technique. That's what I'm saying it's not or don't view it as just. As just a salvage technique, there's no reason why these cows, once they've healed well, as they often do, there's no reason why they can't be retained in the herd for another lactation if they are, if they are not lame, if they are healing well and they do do well.
So moving on to necrotic toes and looking at a different type of intervention, dorsal wall resection. So termincrosis, I'll explain the different types of tone necrosis as we move on. It's estimated that between 2 and 4% of adult dairy cows may be suffering with to, to necrosis lesion.
That's because they're retained in the herd for a long time. It's a welfare issue. It's not nice to see.
That it's not the 2 to 4% of cows that are within a herd get digital, get to crosis. It's just that they are retained in the herd. So once a cow has got this lesion, she tends to stick around for quite a long time because they don't heal by themselves.
So that's why an estimated 2 to 4% of adult dairy cows may be suffering from a to necrosis at any one time. I hope that makes sense. It doesn't mean that 2 to 4% of adult dairy cows get a lesion every year with this, because some of these cows are retained in the herd for several years, and that's what I'm saying, not good.
Now what you tend to see is cows walking back on the heel because they've got a painful toe, toe necrosis, so you might end up with a slip of foot kind of appearance, and it's, and it's on both sides. It's not just one side. If they're not trimmed, then you see like a Turkish slipper type effect, because they're walking back on the heel, the toes grow very long, and they might look like this.
If they're trimmed By a foot trimmer, and a foot trimmer can sort of go so far with them and they end up with just very, very short toes where the trimmer's taking it back to the point where he's reaching the sensitive tissue, that's as far as they can go, and then you end up with a short toe like the pitcher on the left. So they can, they can look different depending on how they've been managed. So here's an example of a very short day where it has been trimmed to the point of, of, of painful tissue, but this is in itself won't heal the cow.
But unfortunately what happens is these cows get retained in the herd because they have a block put on and they seem to improve for a little bit when they are trimmed and then they just recur. But all the time, being no doubt they're in chronic pain. So what, how would you define a tone necrosis?
Well, I would define it by where you have necrosis on the pedal bone. It's where the pedal bone, the tip of P3, is infected, and here is an amputated. A digit from a tone necrosis cow, it would have been very chronic, and you can see how that pedal bone is very truncated because of the necrosis on the pedal bone here.
Now, there are 2 types of 22 etiologies. Type 1, which is classic, would be an infected toe ulcer. Sometimes due to overwear or over trimming, and in Canada at least it is referred to as checkerplate disease because checkerplate being the steel, very abrasive metal plates in trucks used to transport cattle around the country to the feedlots and then feedlots from the feedlot to the abattoir, and it's a very classic syndrome they see because they get very abraded toes and they get a toe ulcer that becomes infected and that then becomes a necrotic toe.
So there's an example of that. Now this is what I'm saying is more common in my experience in the adult dairy cows that we see in the UK. It is not overwear at the toe, and they don't stem from toe ulcers.
They stem from what I'm called type 2, an infection which tracks down the axial wall, and it's like a white line abscess tracks from the white, the white line to burst out of the coronary band. Just imagine the infection coming in the opposite direction. Because it comes in the opposite direction, you're getting infection down towards the toe end.
And again, I'd associate this very much with treponemes, distrepones. And then an abscess forms at the toe end. It hasn't, the pulse has nowhere to go.
And until a foot trimmer, whether it be the farmer or a foot trimmer or a vet, trims the tip of the toe off and releases that pus, then. It isn't seen as a necrotic toe, but at that point it is then therefore seen as a necrotic toe, and she remains in the herd with what the farmer called a rotten toe. So let me just show a few photographs.
To explain, this is an atypical case but clearly shows that there is necrosis at the petal bone here and yet there is no breach of the soul. There is no breach of the soul. This is not started with the soul ulcer.
It has started from infection here that is tracked down under the laminae and formed a nodus or nidus of infection of the petal bone here. And you can see that as a close up. Now always assume that there will be that tract, even if it's not immediately obvious to you.
There will be a tract if these are the type 2s, they start at the coronary band and track downwards, there will always be that tract to the dorsal or axial coronary band region, even if you don't see one to start off with, and that's quite sometimes not unusual on chronic cases. So here's our necrotic toe, and if we follow it, there is a tract that comes out or started if you like here. But it's not always easy to see.
Sometimes it's easy to see. So here's an amputated example, and there's an obvious tract and a split wall, and there is even an associated digit digital dermatitis lesion here which is still present. The majority of them, the digital dermatitis lesions has probably come and gone, but that in my view would be the initial cause.
So think digital dermatitis lesions on the coronary band, particularly at the front of the toe. Those, that, that infection leads to underrunning of the, of the, the inner wall. Infection at the toe end Cow's lame Trim toe releases the puss.
Classic rotten toe look. Sometimes I have an obvious split wall here, sometimes it's not obvious, but what I'm saying with these type 2s is there will always be a tract that goes from the toe to the coronary band. You need to know that because if you don't know it, then you can't treat them.
So If you imagine digital dermatitis here, infection tracks down towards the toe end following the line of the distance following the lamin here. This is just a hoof wall that's been boiled from a cow's foot, a dead cow foot obviously dead cow removed just to show you the laminate, but you can see how a reverse direction travel of infection goes towards the toe end. So we're talking about dig dermatitis at the coronary band, and it's often here, by the way, on the axial surface.
And it tracks down via the lamin to cause an abscess at the toe end. So here's a classic case cockback toe walking on its heel, thin, skinny, empty, painful cow. That's its foot.
Cure it without doing a digit amputation, which is an option. Radical resection, so day naught. Under IVRA removing all Unattached horn to the point of firm attachment.
Remembering that there will always be attracted to the coronary band, you must take it all the way to the coronary band and hopefully those photographs show. That that has been the case. There's also been some underrunning of the wall on the, on the, abaxial surface again, that's been removed.
Day 14, this is the same foot. Starting to get granulation tissue now and keratinization, not only granulation tissue, but keratinization of the exposed chum. If you control the digital dermatitis, you will get characterization of the corum.
Day 21 Very close to healing now, the same foot. Day 28 And that's the same cow. And that's using that approach.
Sometimes you need it for quite a radical resection. So here's a very, very radical resection, but again remember tracked. Up to the carry band, you must find that tract, otherwise it won't get better.
Here's another one where less of a resection is required, but there's the tract. Necrotic toe can re band, find the tract. Curate it out Treat the dig dermatitis, healing, same cow one month later.
Looking at control of to crosis within a herd, well, the key to it is control of dig dermatitis. Now, particularly at the front of the coronary band, and this is to do with foot bath depth, which is being critical. I think we are starting to see less necrotic tone necrosis now because I think we're starting to see farmers controlling digital dermatitis better, including at the front of the of the of the honorary band there.
Early detection and treatment in new cases, and then this do for treating, then remember you must do a dorsal wall resection. So you must remove all the unattached horn. This is, it's not often that I've seen what might be an early case, but here's an example of one that I photographed at the time.
So, dig dermatitis, top of the coronary band on the front of the foot. Under IVRA trimmed away to expose to the point of firm attachment, and you can see diff dermatitis starting to track down here. This wasn't a necrotic toe.
I think it was a cow that was on the way to becoming a necrotic toe. Controlling the dhal dermatitis well with exposure to air and tetracycline spray. Start to get granulation tissue at 14 days.
There's a healthy granulation tissue bed there that's not painful to the touch, so we know it's healthy, but still keep the blue spray, keep keep it sprayed to stop the dermatitis getting in there, and then that granulates over. And there's a key learning there, and that is, is that So, it keratinizes over is that you don't need to for curing these wall defects, you don't need to have healthy wall growing from the top and growing out. It does keratinize as long as you've got a healthy granulation tissue bed underneath, which is nice to know.
And that account was perfectly sound, from that point onwards. Finally, and I'm conscious that we've been going exactly one hour. I just have, a couple of, slides just to finish off with because there was a treaty of complicated claw horn lesions.
I just want to turn our attention just very briefly to something which I feel is very current now. We go through trends like say 30 years ago. I saw a lot of cows with disin joint infection, club feet, having digit amputations.
Then I went through a phase of seeing a lot of cows with to necrosis. We still see a lot of those, but I think probably a few less. Now I'm going through a phase of seeing a lot of cows that are lame through over trimming, and this is the new epidemic we need to be watching out for.
And essentially it is with the careless use of rotary disc grinders taking too much horn off. Not every cow has long toes. They don't need trimming.
And here's an example of a cow that has toe been trimmed too short, you trim the toe short, then you tend to trim the sole too thin, and you have a very soft sole here, which causes bruising. And again, similar thing. Suspect over trimming, extremely thin sole exposed corium.
This wasn't a white line disease. It's just exposed corium due to the trimming, and those are very painful. And of course it leads to secondary dermatitistrainem infection, non-healing lesions.
And just to make the point that a lot of cows will have toes that are already short enough and soles that are already thin enough and as part of their hoof check rather than hoof trim, hoof check is a better word, then all that those cows require is some modelling over the points where the pressure points are that cause classic soul bruising as shown in this picture here. So it's remembering or getting that point across that Not to over trim and check. Toe length and sole thickness very carefully and ensure the foot trimmers you work with do the same.
Finally, further resources. There's a great little resource. Made done by printed by AHDB, HDB dairy, and it's called the Hoofca Field Guide.
And you can order that online, through AHDB. It doesn't tell you a lot about the surgical treatments like I've been going through because it's designed for farmers and foot trimmers, primarily, but it does talk a lot about, treatment of, of normal non-complicated claw horn lesions and also tiss rheumatitis infections. And there is a new version about to be printed later on this month.
I'm talking in July 2024, so from the end of July 2024, expect a new version of that booklet, and it's a great booklet, a great resource. If you're more interested in further resource on the surgical aspects, which is the, the, the prime focus of today's conversation, then I'm bound to recommend, aren't I, because I was a co-author. The little book Bovine Surgery and Lameness is the sort of thing that you can have in your car, in the dashboard.
Or certainly on the practise shelf, and it has a lot of different bits in it, but about a third of this book is all about, is about dealing with with limb disorders, and the vast majority of those limb disorders are involving the feet. So it includes some of those digit sparing techniques that I talked about, even though I don't recommend them. And it also talks in more detail about how to manage those.
Difficult wounds when you do a digit amputation. So very find surgery name this handy little book with lots of tips. Thank you very much.
I hope you've enjoyed today's topic. It's been a whistle-stop tour. Lots of information in there.
I hope you found it useful. Thank you very much.