Good evening everybody and welcome to another in the dermatology series. We are talking tonight about problemers and we are very happy to welcome back Peter Forsyth who presented poto dermatitis to us a fortnight ago. Before we go across to Peter, I would just like to do a little bit of housekeeping.
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If you've got any questions, pop them in the Q&A box and they will come through to me, at the end of the session. And then Peter has agreed to, To answer those questions for us at the end. So Peter Forsythe graduated from the Royal School of Veterinary Science in Edinburgh in Scotland in 1983 and he worked in mixed general practise for 14 years.
He then gained his Royal College of Veterinary Surgeons certificate in small animal dermatology in 1992. He left general practise in 1998 and he had a two-year residency at Royal Deck where he gained his RCVS diploma in veterinary dermatology in 2001. He then founded and is currently a partner in the dermatology referral service with centres in both Glasgow and Aberdeen.
He's an RCBS recognised specialist in veterinary dermatology and he also holds an honorary lectureship in dermatology at the Royal Dic School. As well as at the University of Glasgow vet school. He has particular interest in otitis and bacterial skin disease.
So Peter, welcome again to the webinar vet and it's over to your capable hands. Thank you, Bruce, for that introduction and, good evening, everybody. It's another beautiful evening here in Ayrshire.
Probably far too good to be sitting inside doing a webinar, but there we are. Welcome. Yeah, tonight I'm gonna be talking about, problem ears, as Bruce said, and this is something.
I've got a special interest in, and it's something I spend a great deal of time involved with in our referral practise, because otitis externum, which is really what we're talking about tonight, is a common condition and we extrapolate from Peter Hill's 2006 paper in, in, The record on the frequency of various presentations in, in small animal practise, then titis makes up something like 7.5% of all small animal consultations. So nearly 1 in every 10 patients that you see will have an ear problem.
And certainly in our practise, this data is a bit old actually, probably need to go back and renew it again, but look at it again, this is, this would be from a good few years ago now, but. In a six year period, with 2,362 new cases, 1,171 of them, so, and these, bearing in mind these are all dermatology cases, der dermatology referrals, just under 50% of them had otitis in the history text, so it's a really common problem for us to see. And about 1 in 10 of those cases will go on and have a video otoscopy procedures, which suggests that they've got quite severe otitis.
So, yeah, I don't think anybody probably needs convincing that we're dealing with a, with a common problem. And it's a difficult problem, a frustrating problem in many ways, for a number of reasons. So one of them is that otitis externa is nearly always a recurrent problem.
So if a dog comes into you once with otitis, there's a pretty good chance you're going to see it again and again and again. And again, and it might be something that recurs in a couple of weeks, or it might be something that takes 2 months, or it might be a year later, but there's a pretty good certainty, certainty that you will see that patient again. And the problem with this recurrent nature of the disease is.
If we don't address all the. things that are contributing to the otitis, and we'll talk about what those things are in a minute. Then there is a fair chance that it will progress to chronic disease.
Now, there definitely are dogs out there that have recurring otitis externa and they get treated with Proprietary topical therapy on a fairly regular basis and they, They don't progress to chronic disease and, you know, we get away with it for that, for the, for the dog's life. But those are the lucky ones, and the unlucky ones will progress to chronic severe otitis external, which becomes a really difficult disease to treat. Very frustrating condition for.
Owners and vets and a, a welfare issue for the dog. And dogs are incredibly stoical, you know, they tolerate ear disease amazingly well, but it's only after we've treated the disease often that the owner appreciates just how much the disease was affecting that dog's well-being, you know, they suddenly start playing with their toys again and behaving like. Yeah like young dogs and puppies.
So, yeah. So what I want to do tonight is to look at, first of all, a bit of anatomy and physiology and the, the, the, the health of structure and function of a healthy ear. And then the causes of rotitis, this PSPP system that I'll introduce, which for those of you who are watching the proto dermatitis, webinar a couple of weeks ago, will sound very familiar.
And then look at the clinical approach to otitis, and then the general principles of management. And to be honest, The general principles of management of otitis are the same whatever kind of infection or process it is you're dealing with, and in many ways, you know, the, the severity of the disease and the longevity of the disease. That regardless of that, the general principles of management will remain the same.
So, let's have a look at the anatomy and physiology of the of the ear canal, so. The ear is, you can see this pointer, OK, so the ear is supported by two cartilages or the ear canal. There's the oricular cartilage, which is a spiral shaped cartilage that rolls around to form the pinna and the vertical canal and part of the horizontal canal, and this articulates with the annular cartilage that is just a ring-like cartilage and actually part of the, and we've got the vertical canal here and the horizontal canal here.
And this projection of cartilage from the medial wall of the ear canal is called, some people call it Rosic Chuck's ridge. And, part of the horizontal canal is actually, bony, there's a projection from the external acoustic meatus, the opening into the middle ear cavity, that's a sort of bony projection, it forms this bony shelf, and then the tympanic membrane sits here, and you can see that it's actually not. Vertically across the canal, it sits at an angle of about 45 degrees.
So you get this little pocket forming down here. There's often a little tuft of hair that grows in this region here, which is a good guide if you're working down in the air canal. You're not sure exactly where you are.
If there's no tympanic membrane, if you see that tuft of hair there, you know, the membrane should be just proximal to it. And the whole of the canal is lined with skin, and, there, there are variable numbers of hair follicles in the skin, and depending on the breed. Obviously some breeds like poodles and bichons have particularly hirsute ear canals.
And then there are varying numbers of sebaceous glands and also ceruminous glands, which are modified sweat glands. And the lining of the ear canal should be this nice pale pink smooth colour, you can see there's a few hair follicles down here. You can see the tympanic membrane quite clearly.
This is the pars tensor down here and this. Pink bit up here is actually the part flaccider, the bit of the ear the tympanic membrane that flops around. And in behind there are the round and oval windows of the cochlear.
So you, if you're going to make a hole in the tympanic membrane you don't want to make it there, you make it down here. And this C shape structure which points. Rostrually, so this is, rostral, ventral, dorsal and caudal.
This seaside structure is the manubrium, which is the insertion of the malleus. And the ear canal, this skin lining the ear canal, constantly replaces itself, and the gland, the glands produce secretion, and that mix of the exfoliating cells from the, lining of the ear canal, and this glandular secretion is what makes up serumen or ear wax. And there's a mechanism in the healthy ear.
This is a very important concept for getting rid of that wax. Otherwise the wax would just build up and, and completely fill the ear canal over time. But the way the ear copes with this wax is a process of epithelial cell migration.
And what that means is when The lining of the ear canal replaces itself. The cells, the corneocytes slough off in one direction, so that there's a constant movement of the lining of the ear canal in an upwards and outwards direction which carries the wax up and out of the ear and keeps the ear clean. It moves very slowly, about the speed your nails grow at, but it's, it's enough to keep the healthy ear clean and.
Problems with epi epithelial cell migration, lead to, well, epithelium cell migration can be affected by otitis externum. We'll talk about that in a minute. So here's a quick video of what this, the ear canal, healthy ear canal looks like.
And this is the ridge here, you'll see and this structure here is very sensitive and it's what you bump into with the otoscope if a handheld scope, and you've got to work the cone down round that to look down into the horizontal canal. And here's, I'll just stop it there. So here's the past flaccider, here's the past tensor, here's the C-shaped, manubrium.
This is of the right ear, and this is Rostral on this side. And here's this little tuft of hair that I was talking about. And you can see that the tympanic membrane, the laid a tensor, I'm sorry, is quite translucent.
You can actually see that white area there, that's the, light reflecting off the septum bulla, which is the divides the middle ear cavity. And there's a little bit of wax in there, but this is an otherwise, this is a nice healthy looking ear canal. So, otitis externa is very, like protodermatitis, is a complex and multifactorial condition, and there have been attempts over the years to classify the Things that contribute to otitiss and like protodermatitis, in fact, the proto dermatitis stuff is derived from this.
With ear disease, with otitis, we talk about primary and secondary causes of inflammation. And these are the primary causes of inflammation are those diseases which cause an inflammation in the ear in their own right. And Just about any skin disease can do that.
Any skin disease can, virtually any skin disease can affect the skin within the ear canal, and we'll look at some examples of that in a second. The secondary causes of inflammation arise because there are changes within the ear canal caused by the primary, caused by the primary causes of inflammation and, Really, when we talk about secondary courses of inflammation, we're mainly talking about infections. And then there are factors that, either predispose or perpetuate ear disease.
So, predisposing factors are those, often congenital or, environmental, factors that make it more likely that the dog will develop otitis. Not cause otitiss in their own right, and perpetuating factors which are really important to understand. Are those changes that arise within the ear canal as a result of inflammation, be it primary or secondary, and we'll look at what those things are in a second.
And it's really important when we're dealing with a case of otitis, to try and identify and deal with, address as many of those causes and factors as, as we can in order to have a, a, a chance of permanent resolution of the otitis. Let's look at primary causes of hepatitis. What are they?
Well, the fast. Majority, or the most common one by far is allergic, disease. So atopic dermatitis, food allergy, and, out of these 300 cases, so 2/3 of them were, We allergic.
But there are a whole load of other things, hyperthyroidism, foreign bodies, demiosis, otterecty. Oodectes ear mites, you can see are a relatively small percentage of, canine otitis externum in cats, but, not so common in dogs. Diseases like sebaceous adenitis and a whole raft of others.
It just reflects the fact that As I said a second ago, you know, just about any skin disease can affect the ears and be a primary cause of inflammation in the ear canal. So Atopic dermatitis is the most common primary cause of inflammation, and in the early stages of the disease, what you tend to see this is an outside in condition, so it tends to start in the medial pinna and you've, all you've got here is some erythema and the dog's probably shaking his head and scratching his ear. but the irritation is just due to the allergy.
And when you get an otoscope and you look down the ear, this ear canal will probably look quite normal. As time goes on, though, the inflammation will extend down into the ear canal, and probably you'll end up with secondary yeast or bacterial infections, and the ear will start to look a bit more like this. And I, there's not time to go into the .
Diagnostic features of atopic dermatitis, but just to remind you that the clinical presentation is, is often fairly characteristic, and these dogs tend to be pruritic over the face, muzzle, periocular areas, the ears, the axillae, the groyne, perineum, and paws, and that's the classic atopic dermatitis, distribution. And other primary causes of inflammation, we mentioned in dogs, relatively otodecty is relatively uncommon, but much more common in cats. So oiddectys, demidiosis can be a primary cause of inflammation in the ears.
This dog had generalised demitocosis, but the ears are clearly inflamed, and when you extract the ear wax and mix it up with some liquid paraffin and look at it under the low power light microscope, you find themodex canni mites swimming around in it. So this is sebaceous adenitis, a scaling skin disease. And this is, an autoimmune disease, Penthigus foliatus, which is causing, which is a sterile pustular, skin disease causing lesions on the pinny and actually can extend down into the ear canal.
As well as obviously more generalised lesions. So, This is A dog that was presented with a . Horrible purulent pseudomonas orittis and the dog was going to go for surgery actually but they sent it to us and actually this dog had a foreign body in its ear and that's a piece of plant material that's penetrating the Tympanic membrane through into the middle ear cavity and removal resulted in resolution, and interestingly this dog had the same problem in the other ear at the same time, so you can have bilateral, foreign bodies.
With otitis. So, moving on, I just want to talk briefly about the secondary cause of inflammation, which are the infections. And I think with otitis there, perhaps there's a bit of a focus on dealing with the infection and, and then hoping that everything else will sort itself out.
Well, that's often not the case. Dealing with the infection is, is only ever part of the, Of the solution of in dealing with otitis, it's it's certainly important in some, in some cases. But, so the most common secondary course of inflammation is, it is infection, and we'll look at some different types of infection in a second.
It's not the only one though. So occasionally we'll see dogs where we've treated, ear disease and they're on perhaps. Some longer term you cleaning therapy or something like that, and then the disease starts, seems to start to recur.
And you should always suspect that there could be a reaction to a topical medication in a situation like that, and that's what this is on the media aspect of this boxer's pinner. This is a reaction to prolene glycol. When we're talking about infection in the ears, we can divide these infections up into two main groups.
There are the commensal organisms, those bacteria and yeast that will colonise the ear canal, and are found naturally in the ear canal, albeit in very small numbers, and malacasia and Staphylococcus will be the two most important ones. And they will multiply if the environment within the canal favours their favours that, and the increase in discharge or changes in the environment due to, alterations, arising from, underlying allergic disease, for example, will favour the growth of, of those organisms and eventually you'll get to, they'll get to a level where you have active infection. But there are also, otitis can also involve, bacteria that are not normally resident within the ear canal.
And that, and that includes organisms like Pseudomonas, which is a, a soil and waterborne organism, and, enteric or, bacteria like E. Coli or clepsella, for example. And usually, Those types of infections are associated with longer standing disease in the ear, and I think possibly partly often associated with the prolonged use of topical or the repeated use of topical antimicrobials, we probably select for those, bacteria, where, where they couldn't get, if you like, a toehold in the ear, initially, with the repeated, the changes brought about by chronic disease, and the repeated use of topical antimicrobials.
Then they gain, they can establish themselves in the ear canal and cause infections, so they're typically associated with longer standing disease. . Occasionally though, in some breeds, we do see very acute onset pseudomonas otitis, and I'm thinking about the cocker spaniel in particular.
Doesn't, sometimes there doesn't seem to have been a previous, you know, there hasn't been a, a long history of, of, previous episodes of titis. So That's the primary and secondary causes of inflammation. Moving on now, I want to talk about the two sets of factors, and firstly, talking about the perpetuating factors.
What are perpetuating factors? Well, there are changes that occur within the canal, . As a result of longer standing inflammation, and there are changes in both cancer and also the function of the ear canal, and the, then the effect of these changes is to favour further microbial colonisation, and also, they tend to either inactivate or prevent penetration of topical therapy, and they are, they are.
The main reason for persistence or recrudescence of disease, and they probably are the main reason that otitis cases, or, or very common reason that otitis cases are referred, to us. And they include, but are not limited to. Situations like stenosis of the ear canal that can be from swelling or, hyperplasia of, of structures within the ear canal such as ceuminal glands, and discharge the discharge, and we'll look at how that arisesitis media which, In my experience, it's less common than people think.
And I'm not, it's really a subject of another lecture in itself, so I'm not going to talk much about that. But I do think that the inappropriate use of topical antimicrobials, so these dogs that, these owners that have a bottle of something or other at home, and every time the dog starts scratching his ears, because it probably has an allergy, they put the drops in for a couple of days and lo and behold, the steering in the drops, stop the pruritus. And they use that again and again and again and I, you know, I, I, I think we then are in the situation where then selecting for resistant organisms, especially those gramme negatives we talked about earlier on.
So here's a healthy looking ear canal, this is actually a cat's ear, but, that's neither here nor there, and what. If what happens is you have a primary cause of inflammation, let's say it's an allergic skin disease, atopic dermatitis, that has some effects within the ear canal. It probably causes an increased production of serumen.
And, increased exclamation and enlargement of the, of the glands lining the canal, the, the, the results in the net effects and increased production of ceruen, and it probably also affects. Epithelial cell migration, so the net effect is you have a buildup of discharge within the ear canal. And it doesn't, you know, take much imagination to realise that that's gonna be a wonderful environment for the growth of yeast and bacteria.
And that when you put topical medication in that ear, it is simply not going to contact the lining of the ear canal where it needs to get to in order to be effective. So here, this is on the picture on the left represents is, is a common scenario. This is a.
A boxer's ear. This is an atopic boxer. This is a very typical boxer ear, actually.
And looking, we're looking into a horizontal canal, and there is thickening of the lining of the ear canal and, swelling of the soft tissue. So we've got we've really got hyperplasia of the epithelium and swelling of soft tissue, leading to almost complete occlusion of the, of the horizontal canal. And you can see the swelling is causing.
The tissue to be thrown into these sort of folds, and these clefts and crevices are a wonderful environment for yeast and bacteria. And, your topical medication simply will not penetrate down here. This is a situation we're often referred cases like that saying this dog doesn't have a tympanic membrane.
And so Somebody's looked down the ear canal and they've got those black hole here, this is where the eardrum should be actually. That's not the case. In behind this stenotic area is an intact tympanic membrane, but it's only when you get this cleaned out and reduce the swelling, probably by using glucocorticoids that you can then visualise the membrane.
This is cocker, this is a spaniel change. This is seruminal gland hyperplasia. To become quite severe.
So you might see this, this is actually from a Welsh swinger spaniel, but this could easily be a cocker spaniel or a springer or a, or even a cavalier King Charles spaniel, with this marked kind of nodular appearance of the lining of the ear canal. So that's ruinal gland hyperplasia, and that's a, a cla a typically spaniel, change, and you know, again, it's causing stenosis of the. Lining of the canal, or stenosis of the lumen of the canal, rather, and will affect, how well topical medication is going to work.
And again, the, the treatment for this would be systemic glucocorticoids to try and reverse this, these changes. And, eventually, fibrosis, if, if the ear canal becomes fibros or calcified, you can have complete irreversible stenosis. Of of the canal and it's represented here, you simply cannot see the opening into the vertical canal in this picture on the right.
The other thing I just wanted to mention are things called seruminalis. These are. Little plugs of wax, and hair and sometimes topical medication that collect in the very proximal horizontal canal.
And the thing about these is that they can. When you look down the ear, often the ear canal looks normal, but you cannot see the tympanic membrane. And sometimes these things can be a reason for recurrence of otitis.
They're not always, sometimes we see these incidentally, and they're not really causing the dog a problem. Sometimes they can be irritant in their own right, but sometimes they harbour yeast and bacteria, and, can be a reason for, so they become a perpetuating factor, really. So this is a a video here of a swimmer they see this looks here and it looks OK.
And then you get right down to the bottom and you've got this plug of wax sitting there. And usually if we see these we will remove them, this one. Came out very, very easily, just using, fine forceps that go through the, otoscope, the working head of the otoscope.
Usually this doesn't happen. Usually these things break up. This one came out in one nice lump.
. Which was very obliging of it. So that's a seruminolith, and if you do see them and the dog has caring otitis, then, you probably want to be thinking about removing these things. Predisposing factors are other factors that that make it more likely that a dog is going to develop otitis, but, do not, cause otitis in their own right.
And the best, probably one of the examples is in this breeder Shar Pei, where they have congenitally stenotic ear canals and the pinner that shuts very tightly over the lid of the opening of the ear canal, trapping moisture and, and not allowing, the circulation of air. And, and of course, on top of that, many of these dogs are atopic, so they are, an otitis waiting to happen. But there are, there are others, swimming is one, dogs that swim regularly are predisposed to develop otitis because of the mass maceration effect of the moisture, hair in the ear canals, and so on.
Oops. And obstructive ear disease, so there's a polyp on the, on the wall of er on the wall of vertical canal, yeah, vertical canal and . While that doesn't cause disease in its own right, it can predispose towards the development of otitis.
So really, when we're dealing with otitis, we want to aim to prevent cases of chronic otitis. So we, we want to try and avoid this situation here. This is an atopic dog that's had otitis for many years and it now has ends, you can see it's also had oral hematomas.
It now has end stage ear disease, and the only option for this is a totally canal ablation and osteotomy. So we want to try and avoid this situation, and that means addressing all the causes and factors that we can identify. Contributing to the otitiss early on in the course of the disease, and we need to convince our clients that that's worth doing, and many of them just want, repeated eardrops, but we've got to warn them that that's not in their pet's best interests.
So what's the approach to otitis? Well, it, it's definitely, even in a 10 minute consultation, it's definitely worth taking some history. The first thing you want to know is how long has this ear disease been going on for?
So how has it been, is it a first time presentation, or is it something that the dog has had repeatedly, and that should be hopefully in the clinical notes, or is it, is it a, a, a, a, a chronic ongoing problem? Also, is there other evidence of skin disease? So, so does your dog chew his paws or rub his face, or?
You know, it round his perineum or, or over the ventral abdomen, suggesting that the dog might be atopic or has it got other skin problems to know about which could be an indicator as to the primary cause of the otitis. Could there be exposure to a foreign body? Is the dog a swimmer?
And those that those would be the those would be the sort of baseline his baseline history you'd want to take in a, in a, in a 10 minute consult if possible. And then it's worth, when you're examining the dog, have a look at the rest of the dog's skin, you know, have you, has the dog got erythematous paws? There's other lesions of the ventral abdomen?
Has it got pyoderma, for example, examine the external ear canals, look at the nature of the discharge that might be present. I like to pop a pair of gloves on a heel, in the dog's ears, and even dogs with very painful pseudomonas oti is will tolerate this very well, where they will not tolerate otoscopic examination, they won't tolerate the cotton bud, but they will tolerate you putting your fingers in the ears, and you can tell quite a lot, you know, are the, are the, are the ear canals nice and mobile and elastic, or are they rigid and, and fibrotic or calcified, . And when you remove your fingers, you then have samples ready for cytology for smearing onto a slide.
Consider otoscopy, but it can be painful and shouldn't be done if the ears are very inflamed. If you are going to, and if the eyes are ears are very inflamed, you either have to sedate the dog or give glucocorticoids for a few days and have the dog back, once the inflammation has settled down. Obviously, if you suspect a foreign body, you'd probably want to get the dog in straight away, and for sedation and examination.
And when you're doing otoscopy, it's important to examine, you know, the external ear, the vertical and horizontal canals, and the tympanic membrane. You should be able to visualise the tympanic membrane in a healthy ear, and you're looking for changes. In the ear canal, including things like foreign bodies and the nature of the discharge, and there is the ear canal stenotic.
If the ear is like this, you're not going to be able to do otoscopic examination. And all you can do with this dog, if you're going to try and manage this medically, is, is systemic glucocorticoids, probably prednisolone at maybe 1 milligramme per kilogramme for 2 to 3 weeks to try and get this opened up. And if it opens up, that's great.
You might be able to do something with it. If it doesn't open, it's probably a surgical problem. And ear cytology is really the most important diagnostic step for otitis.
It is a principal guide to selection of treatment. It allows you to follow the case up. So what I mean by the principal guided selection treatment, you, you know, you, you, you can see whether there are yeast or cockeye odds in the canal, or whether indeed there's no evidence of infection at all, in which case, an antimicrobial robial would not be indicated.
It allows you to follow the case up after you've treated it. And make, it's really important to follow these cases through and make sure you've eliminated all signs of inflammation and infection. And, it facilitates following cases over a period of time.
So you might find this dog that presents once with, an otitis has a, a malacasia infection, the next time it might be a, a bacterial infection. And then at some point, you may start to see rods creeping into the cytology, and that's the point you really want to get in there at that point and, and address all the causes and factors with that loittis case. So let's look at some examples of ear cytologies, this again, could be electron in itself, but in this example here, what we've got, all we've got here are just squams.
These things are these keratin bars that we see from head skin, but there's no evidence of infection in here. There are increased numbers of squams, and this would be consistent with a hypersensitivity within the ear canal. In acute otitis cases, we tend to see either malacesia, or cocci, and I used, but this purple streaky stuff is probably squashed neutrophil nucleus, and represents the presence of, of inflammation within the ear canal, and it's an important thing to be able to recognise.
So that's acute otitis in longer standing otitis cases, we'll usually tend to start to tend to see rods. And sometimes mixed infections. So you may see rods and malacasia or rods and cocci or rods and coccie and malacesia.
And, sometimes we'll start to see, pus, it can also, so neutrophils often associated with rods, and typically that would be a pseudomonas infection. And the thing that we see kind of increasingly commonly now is a purulent malacisio otitis. So we see a combination of maleshesia organisms and neutrophils, and these can be particularly difficult cases to manage.
They're often quite refractory to treatment and need prolonged therapy to get on top of this problem. It's a thing to watch out for. What about culture and sensitivity?
When is that indicated? Well, it's, it's never wrong, but it's certainly not a substitute for cytology, and, and. Culture and sensitivity, and we get lots of phone calls from people saying I've cultured this pseudomonas and it's resistant to X, Y and Z, and what am I gonna treat it with?
Well, the truth is that, Therapys concentrations, really high concentrations that often overcome apparent in vitro resistance. So even though your, your cultural sensitivity report may say it's resistant to, you know, a fluoroquinolone or whatever, you may well find that that antibiotic still works when used topically. So, you know, you need to take that into consideration when interpreting the results of culture sensitivity tests.
But we will do them if there are unusual organisms such as rods or if they've been if the dog's had multiple previous treatments. Do certainly do them if there is evidence of a Titis media and the the sample that you need is a sample from within the middle of your cavity, so you need to . Aspirate some fluid from the middle ear and submit or, or, or introduce a very fine tip swab into the middle ear and, and use that, for culture, in that situation.
We'll also do it if there's a history of possible history of exposure to methicillin resistant organisms. The important thing is that your culture results should correlate with what you see on cytologies. What you see on cytology that counts.
And if, if your culture doesn't correlate with that, then it's probably not relevant. What about ageing? Well, we don't do much imaging, mainly because we don't have imaging facilities in, partly because we don't have imaging facilities in our practise, and partly because we find we don't really need it very much.
But there's no doubt that if you suspect middle ear disease, that radiography or CT or MRI can be useful in assessing, the middle ears and making some decisions on whether you might be able to manage a case. Surgically or whether, sorry, medically or whether surgery would be indicated. But just remember that quite a high percentage of cases of otitis media will have normal, if you're using radiography, will have normal appearing buller radiographs, whereas CT is a much more sensitive test.
So, I want to move on now, so you know, the the key things really when we're working out those dogs, look for, primary causes of inflammation, so question the owner about concurrent . Skin signs so pruritus or other skin lesions, . And examine the ear as best you can if necessary under sedation, but, always do your cytology, that's really critical.
And then if the ear disease is very chronic, then you might consider imaging as well. I want to move on now to talk about therapy and the aims of therapy and this, you know, the, the therapy really this pertains to, Any kind of otitiss really. Whatever infection it is you're dealing, whatever, whatever the changes are, then the general principles apply whether it's a malaesia otitis or a staycoccal one or a, or a, or a dog with a Fining pseudomonas, the same basic principles apply.
And what we've got to do is res first of all, attend to those perpetuating factors, so. Clean the ear effectively and get rid or resolve swelling and stenosis to get the ear canal opened up. We certainly want to eliminate infection when it's, when it's there.
And then in addition to that, we, need to address the primary causes of inflammation, as well as which part, part of the way towards preventing further episodes, but the other part of preventing further episodes of patitis is to keep the ear canals clean in the long run. So cleaning is the single most important thing that we can do when we're treating otitis. And it certainly it not only helps with a treatment point of view, but it also facilitates examination and it removes.
Microbes from the ear canal, it removes discharge so that the topical medication can penetrate and work properly. And many discharges, especially yulent discharges, will inactivate many antibiotics or topical antimicrobials. And there are two ways that we can do your cleaning, either by having the owner do cleaning at home or cleaning under sedation and and general anaesthetic.
So If the ear canal is not, if I can see down the ear canal, and particularly if I can see part of the tympanic membrane, and there's just a bit of discharge down here. And the ear is not completely impacting material, then we'll impacted with material, then we'll usually have the owner do try air cleaning at home. And it's really important to demonstrate to them how to use the air cleaner effectively.
So, I like, I recommend that owners just warm it. In hot water so that it's a body temperature when it goes into the ear canal, and that's tolerated much better by dogs than something cold being poured into the ear. They fill the ear canal right up with whatever ear cleaner it is they're using, and they massage the vertical part of the ear canal for 30 to 60 seconds and then wipe away any material that comes out.
And typically, Typically they will clean the ear unless the ears is extremely dirty, in which case you're probably gonna have to clean the ear under sedation or GA, but typically we'd have them using an air cleaner twice a week. And there are lots of different cleaning fluids available. Again, that's the subject of another lecture.
But it's important to consider what kind of discharge you've got and what it is you, you want the air cleaner to do. So if it's a pussy purulent discharge, like a pseudomonas infection, then you want to use an aqueous solution and something that's gonna be. Not painful in an ulcerated ear, which rules out the acidic ear cleaners.
So we would often use Triz or tris chlor triyDTA chlorhexidine combination, for that type of situation. These are aqueous air cleaners, so they don't dissolve wax. If you have a waxy air cleaner, then you want to select a serumminolytic air cleaner.
You might want one with a drying effect, or you may want something, many of them do have antimicrobial effects and it's important to familiarise yourself with what you have in your practise and what the effects of those air cleaners are. And often it's important to change the air cleaner as the case progresses. So if you have a purulent otitis, you treat the .
You, you treat the, the infection that's causing the purulent discharge, say, the pseudomonas, and . You then find that, the discharge then changes to being a waxy type of discharge. So you then need to change your cleaners, to a serum lytic one.
And so it may be necessary to change cleaners, as the case progresses and. Be careful when the tympanic membrane is ruptured, so. And Many aqueous products, so Tris and Tri TriTTA and Tris Clo would be safe to use in a ruptured tympanic membrane, and, and, and squale should also be safe, but many, most air cleaners are, are contraindicated in that situation.
If you have a dog with a, a very, profuse, . Discharge within the ear canal, where you really can't see anything. The, the really the only chance of getting this cleaned out is under general anaesthetic.
And you, it's a retrograde technique that's used. So we use. Well, this is always done under general anaesthetic.
It's, it's not possible, in my opinion, to effectively clean the ears just under sedation. So it's a general anaesthetic. You introduce a serumolytic into the ear or something appropriate into the ear, first of all, to break up whatever discharges is in there.
And then we use a retrograde flushing technique, and typically in before we had the video otoscope, this is the setup that we used, and you can see, I think it's fairly self-explanatory. We use saline in our practise. It doesn't have to be saline.
You can use water, you can use very dilute acetic acid, but not an ulcerated ear canals, or very dilute chlorhexidine. And it's important that following the air cleaning procedure that you use appropriate analgesia. So Tramadol or, or typically we might use some, a sort of paracetamol, codeine type of product.
And also glucocorticoid therapy for a few days cause you create inflammation by doing the cleaning procedure. So this is an atopic Labrador's here with profuse discharge and, you know, we see these. Commonly every day, not, if not every day, every couple of days.
I mean the only way to get this cleaned out is under general anaesthesia, and you can see that there's the catheter there, and we use nowadays we use nasogastric feeding tubes as the catheter because they fit down through the otoscope, video otoscope working channel and they're nice and soft and gentle. And that's what's being used there. And you can see we're just working away at this discharge that's impacted into the horizontal canal.
And, you work away and work away and gently flush, and, and I use the end of the catheter to agitate the material and just gently loosen it, and, and work away at it until eventually, Sometimes after 15 or 20 minutes, you get to a situation, this is edited obviously, where you have a clean ear canal and you can now see the tympanic membrane, and that's the type of cleaning that you're looking to achieve. We mentioned glucocorticoids, I just want to say a bit more about them. They are in very, very useful drugs for the treatment of, many types of otitis.
They're good at controlling prurituss and, and pain associated with, the inflammation in the ear canals. They're indicated for the management of, of stenosis and hyper or hyperplasia and swelling within the, in the canal leading to stenosis of the horizontal canal. And also this sort of situation here, this is a border terrier with a very stenotic external ear.
This completely resolved with systemic leucocorticoid therapy, and this is a West's ear here and you can see the stenosis. Here and afterwards here, after, 2 to 3 weeks of glucocorticoid treatment, systemic predicilin treatment. They're indicated post ear flushing.
They're very useful when we're treating pseudomonasotitis, resolving the inflammation in the ear often produces an environment that's much less favourable for the pseudomonas organisms to to, multiply and thrive. And they're also indicated in the long-term management of atopic dermatitis. So, Typically, with dogs that have atopic otitis, we will include and lead long-term ear cleaning, we will add some.
Soluble dexamethasone. This is an unlicensed treatment, obviously, but we'll add soluble dexamethasone to the ear cleaner or there are no products available. Triamcinolone is now available as an eardrop preparation that can be used on an intermittent basis, perhaps once a week, twice a week, just to control the inflammation in the ear, of, of a dog with allergic otitis.
So glucocorticol is very useful, of course they are present in all the proprietary topical medications that we use. So, having cleaned the ear, and, identified the infection that's present, we're gonna use some kind of topical, very often, topical antimicrobial therapy will be indicated. I mean, if there's a yeast infection or a bacterial infection, then, we're gonna use one of these types of products.
And topical therapy is much more effective than systemic treatment because it achieves much higher concentrations within the ear canal. And we base our selection on cytology combined with the principles of good antibiotic stewardship, and I want to talk about that in a second. And it's important to use the correct dosage, so this dog on the left's ear canal probably holds 20 to 30 mLs of fluid.
This one probably holds 1 to 2. So you're gonna need a much greater dose of whatever it is that you're putting into the ear in this year compared to this one. So, and quite often we'll give the owner a syringe, to draw up.
A measured amount of whatever it is we're putting into the ear, and squirt that into the dog's ear canal rather than just saying put a squeeze of this in the ear or count so many drops of your proprietary medication into the ear, . It's a bit more accurate. So how do we kind of select what it is that we want to use?
Well, I've kind of graded these things, these products here, and at the top, I would say these are the two that are perhaps the ones that might be most appropriate for, malacasia infections or perhaps staphylococcal infections. And the ones in the middle, well, the these two at least. A gentamicin containing products.
So they would also be useful for gram-negative treatments, for, for gram-negative infections, and maybe a bit more of a valuable antibiotic, gentamicin. So perhaps we'd be a bit more careful about where we use them. And for the ones down here with the fluoroquinolones, then we would reserve those for the gramme negative infections wherever possible.
And what about, what about Asannia, the, this relatively new long-acting treatment, which is very useful where compliance, is difficult and, and where the owners find it difficult to apply a medication to dog's ear. . And I, I, I think actually this is probably the, indicated in acute, First or second, you know, early presentation cases, it's probably less useful in the chronic situation.
And all these products are all effective against yeast. In theory, they're all effective against gramme positives and gramme negatives, and, they all have glucocorticoid in them, and they have different glucocorticoid as well. So, you know, prednisolone it's a less potent glucocorticoid than, than, for example, dexamethasone or betamethasone.
So that's worth taking into consideration as well. So this would be Perhaps 2nd line, I know Seria probably sits in here actually, and 3rd line. So typically the treatment regime would consist of, perhaps 2 or 3 times weekly air cleaning, either done by the owner at home or, Having had the dog and and cleaned the ears in the practise, you then send the dog home with an appropriate air cleaner to be, as I say, used twice or perhaps at the most, 3 times weekly.
You use your topical antimicrobial as per, as per data sheet, directions, and you continue treatment, you continue the antimicrobial therapy until clinical resolution. And until, there is no further cytological evidence of inflammation or microbial infection. So you treat until the ear looks better, and you treat until you've, there is nothing to see on cytology.
So, When you do your follow-up cytology, you don't want to see, any yeast or bacteria, and you, and you don't want to see signs of inflammation. And the signs of inflammation, just to remind you, include just these purple streaks of nuclear debris. So if you see this present, you're not done treating it, you need to continue your antimicrobial therapy until this has gone away.
And when you look down the ear, when you examine the ear, you do want to see a clean ear canal, and you need to be able to visualise the tympanic membrane. If you're starting to see this situation where you've got discharge obscuring the tympanic membrane, then you need to address, revisit the ear cleaning technique with the owner, make sure they're doing it properly. A word about Pseudomonas.
This is the one, I think that puts the fear of death into everybody, but to be honest with you, you address this in the same way as you, you, you treat. Other ear diseases, it, it obviously, Is a soil and waterborne organism and it's frequently multi-resistant, but remember that your topical therapy will often overcome that apparent resistance. And it's a painful ulcerative disease, so you, you need to use analgesia in these dogs.
Glucocorticoids are very useful, even when the, especially when the ear looks like this. So systemic glucocorticoid therapy is indicated. Thorough cleaning, so have the dog in, anaesthetize them and get that ear completely cleaned out, remove all that pus because it's the pus that inactivates the topical antimicrobial.
Use an appropriate topical antimicrobial, something that's gonna be effective against the gram-negative organism. And if erittis Media's present, well, that's a bit of another story, but you're certainly going to need systemic treatment. And you certainly if aittis media is present, and as a kind of little insurance policy, I will usually do culture and sensitivity on these.
So if my initial treatment fails, I can then fall back to the results of this and select something hopefully that's going to be effective. So Having treated the infection and the inflammation, we then need to make sure that we keep that ear healthy, and that in many ways is a greater challenge than than dealing with the initial presentation. And a good adage to remember is that ears are never cured, they're only just in remission.
And remission depends on keeping the ear clean, and many of those cases will require lifelong, lifelong air cleaning. And it's important not to over clean the ear, so long term, probably once a week or once a fortnight, may be all that's required. And if it's an allergic ear, adding some of the, you know, adding a glucocorticoid in topically used on an intimate basis can, can be very helpful.
In addition to that, you might in many cases, especially if dogs have. More generalised clinical signs, then diet trials and allergy testing could, could be something that you, you want to do, and you might need to investigate, any, any other possible underlying diseases, or hyperthyroidism, for example. OK, so, In summary, otitis is a complex multifactorial disease, and it's important that we try and identify and correct as many of these primary and secondary causes of inflammation, and these, and manage those perpetuating factors in order to achieve longer term resolution.
Cytology is really important with, initially identifying what type of infection is, is there and monitoring your response to treatment and knowing how long to continue treatment for, and when, when it can be stopped, and also for following cases over a period of time to, to see what sort of changes are occurring with regard to the type of infection that's in the ear. And in most cases of, of ootitis, topical therapy is effective, but it's really dependent on, on achieving a clean ear. And, and usually if you're using topical therapy and it doesn't seem to be working, it will be because it's, in most cases, it's not penetrating.
So if the ear is stenotic, then use glucocorticoids to get to open it up. if it's dirty, then, get it properly cleaned out. And, and, and most of these cases, especially dogs that have had longer term ear disease, will probably require some sort of lifelong, measures, typically once or twice, once a week or once a fortnight, ear cleaning.
And just remember the ears never, never get better. They're only just in remission. OK, well, thank you for your attention.
I'm very happy to take any questions. I think we've got a couple of minutes, have we, Bruce, but. Yeah, Peter, that was absolutely fantastic.
So clear and concise and I I said it to you before we came live on air, but I am so jealous of that video, I just go. What a lovely toy. Be able to show the owners what's going down that ear is, is just fantastic.
Yeah, I mean we, we use it. We video all the otoscopy procedures we do in part of the discharge of that of the dog is showing that the owner the video and it, and it, it really, I think encourages compliance, you know. Well, I think in some of these cases because they can't see it.
Indeed. You know, exactly. Yeah.
Right, Peter, a couple of questions and that sort of thing coming through. So Sally wants to know, do you put all ear cases on EFA's? No.
That's a short answer to that question. No, I mean if you, no, I don't, . And really, I, I don't think, .
I mean, I, we sometimes use EFAs in some cases of atopic dermatitis, or we might use a diet that's high in EFAs, but, The Hills or something like that. Yeah, yeah, that sort of thing, but no, no, I don't, there are much more. If you know, I don't hesitate, but there are more effective things that you can do, I think, but there's, there's no harm in giving them EFAs, but I don't think you'd clinically notice much of a difference.
OK. Another little window that you just cracked open and I'm gonna toss the hot potato to you. Hairy ear canals, should you routinely pluck or shouldn't you?
It's a good question. So I, I think if a dog has never has hairy ear canals, but they've never had a problem with their ears, then I wouldn't pluck them. But at least that's my view, because I think plucking is inflammatory in itself, and if, you know, you're going to create some inflammation and.
If the dog doesn't have a problem, leave well alone. But if, if the, if dogs and particularly those dogs like Labradoodles and Australian Labradoodles and poodles and bichons that have, A predisposition to develop atopic dermatitis and hairy ears, and they often develop otitiss, then I think removing hair from the ear canals is on a periodic or fairly regular basis is, is helpful. So use it as a as part of the treatment rather than as part of the prevention.
Yeah, well, if the dog hasn't had otitis, then you don't need to prevent it. Yeah, yeah. For sure.
The other thing is these long eared dogs like the spaniels and those sorts of things, with their thick heavy ears and bassets with their long ears. What about keeping those ears up with using like stockings or the tights or those sorts of things to allow air to get in there. You're reminding me of my Days in practise back in the 1980s and 90s, you know, my era.
Well, we, no, we don't, and that's certainly something that we used to do, but I, I think, you know, that. It's, it's actually been shown that it's not so much the fact that the ears hang down. It's what these, the, the diseases that these dogs are predisposed to that causes them to develop the, the otitis, because we see otitis just as frequently in dogs like German shepherds with, with erect pinny, you know, so, but I mean, if you find it helps, that's fine, not something that we do.
Excellent. Peter, I think that's all we have time for and it's, it's been a a a truly enlightening webinar as was your poo dermatitis one. So thank you for coming on and imparting your knowledge to us.
My pleasure. Thank you very much. Folks, that's it for tonight.
We look forward to, I think if our memory serves me. Correctly, we have 1 more in the dermatology series coming up. 2 more, sorry, thank you.
I think Hillary's 2, isn't she? Alrighty, well, we have got more coming up. That's the point.
So your emails and don't forget to check for those GDPR emails because otherwise you won't be getting any. And Peter, once again thank you very much to Anna, my controller in the background. Thank you and to everybody who attended tonight.
Thank you very much and good night from me.