OK. Hello and welcome to everyone, listening in for this session. So I'm going to talk to you about how to diagnose atopic dermatitis.

Apologies for my croaky voice. You can blame my son for that. So we're gonna talk about basically an introduction to atopic dermatitis.

So what is it? And then we're gonna talk about a general dermatology history and examination, and then the plan that we would follow to make a diagnosis of atopic dermatitis. So pruritus is a very common clinical presentation.

It, you know, dermatology consults probably account for about 20% of all cases seen in first opinion practise. And certainly puritus is often a very frustrating clinical presentation for clients and for vets because there's so many causes for it. So it's very vitally important that we get a firm diagnosis so that we can manage these cases effectively rather than just guessing or just giving symptomatic treatment, without knowing exactly what's wrong with our patients.

So there are lots of causes of atopic dermatype of itching in dogs. So the most common cause that we see are parasites. So parasites are still the number one reason for animals to be puretic.

So you can probably see in this picture, if the video is working, that this dog was quite itchy. The owner didn't actually perceive the dog to be very itchy, but it was itchy. But parasites are still the most common cause of pruritus in dogs, and certainly if you're seeing cases in general practise, that's the first thing that we need to look at.

But the other thing to remember is that infections can also be very itchy and a significant cause of pruritus in some patients, and allergic skin disease is up there with one of the other most common causes of pruritus, and that includes flea allergy, food allergy, and atopic dermatitis. So we also get some more weird and wonderful causes of itching. So dogs with pemphigus foliacious as this little puppy has here, can be very itchy, so they can present with pruritus.

And initially they might be mistaken for a dog with allergy and secondary infection, because obviously it's a pustular crusting disease. And in our older patients can all with epitheliotrophic lymphoma can also present with red, itchy skin, which isn't very useful, but hopefully, history and age of presentation will help us determine the diagnosis in those cases or lead our clinical investigation. So when we're presented with a, an itchy patient, it's vitally important that we get a good history and a lot of dermatologists bang on, bang on about this, but it is so important.

So when we take our history, we want to know the signalment of our patients. If we're thinking about this dog possibly having allergic skin disease or atopic dermatitis, they're more likely to be presenting at quite a young age, so between 6 months and 3 years, 3 years of age. We, it's important that we try and find out how long the owner has had that patient, that pet in their possession, because obviously some, a lot of people be home dogs from rescue centres and so they may not be aware of the fact that that that pet has only been in.

Has had clinical signs this summer, but actually it's actually 5 years old and it may have itched since it was 6 months of age. So it's very important that we know how long they've owned a dog, where they've acquired it from. We also like to ask questions about their general health and their medical history, because that may affect what we see clinically.

So, for example, if we've got an older dog presenting that PUPD that would raise our index of suspicion of an endocrine disorder. If they are on non-steroidals for their osteoarthritis, then that might affect what treatment we prescribe for their pruritus. Another really useful tip is to ask owners about intact animals and people, if we're presented with an itchy patient.

So the picture you can see there is a Labrador affected with sarcoptes. And when we asked the owner the question if any other in-contact animals and people were affected, the other dog in the house had recently started to itch, and the owners both had lesions on their forearms. And that obviously narrows our differential diagnosis list significantly, because there's not many, diseases that we see in.

Our patients that can be transferred to owners or a zoonotic that cause pruritus. We also like to ask about the history and the environment. So where does the dog sleep?

We know the highest concentration of house dust mites are in our bedroom. And a lot of dogs seem to sleep on the client's bed, in my experience. We also want to ask where they've walked, have they got exposure to wildlife such as foxes?

And it's really, really common for us to find that some of our patients. That present with sarcotic mange, owners will say they've seen foxes in the garden or the dog has, there's foxes very close by, and they are aware of some sort of contact with foxes, which obviously again helps us narrow down our differential list as to what might be going on. We like to ask in detail about the diet, especially if we're thinking about food allergies.

Food allergies are a common cause of pruritus, not as common as atopic dermatitis, but it can be a significant cause of pruritus for some patients. So we want to know what do they feed the dog. What's the protein source?

Do they get treats? Do they get tidbits? Do they get supplements so that we can get a good overall picture of their diet.

And then if we do need to start an exclusion diet, we've got a good idea of what to avoid and what to include what we could use for an exclusion diet. We also ask about their routine management. So if we said that parasites are one of the top causes of pruritus in our patients.

We need to know what flea control they're on. And more importantly than that, other clients actually applying it. So a lot of our patients now will be members of pet healthcare plan.

They'll be getting their flea control very regularly from the practise, but it's important to realise that not all clients will actually apply it despite that. So sometimes when we question clients, it's been assumed that they're administering the flea control, but actually they haven't used it for 3 or 4 months because they don't believe in flea treating in the win in the, in the winter. And they only do it in the summer, but they've got loads at home in their cupboard.

So it's really worth questioning them quite carefully about this, and also how they're applying it or how they're administering it. Have they been given the right weight treatment for their pets? Are they applying the spot on treatment correctly?

Are they giving the tablet correctly? We've certainly seen cases where clients have applied frontline spray, for example, as a spot on as one pump on the back of the neck and not treated the whole pet as we would normally. Expect and you also want to know about the.

Their bathing regime, because if the dogs are bathed really regularly, then that's obviously going to affect the efficacy of their flea control, and that might may make it less effective. So, I think never assume that just because it's been sold, the client's actually using it and using it correctly. And if they are using any regular bathing or they're using a medicated shampoo, take the time to ask them how they're using it, are they allowing a contact time, etc.

Because often clients don't use these things correctly. Because we need to ask a lot of questions and get good background information, questionnaires can be exceedingly useful in our patients, so. I still use a questionnaire regularly for my, for my skin clients.

And I know that a lot of people are adopting this method. So it just saves time because you don't have to think about the questions. You could also get the clients to fill in the questionnaire before you see the dog if you know it's a chronic skin case.

Although in my experience, some clients then don't give as much information as you can obtain from them when you actually ask them yourself. So we've now got all the background of our patients, we know what, you know, what their lifestyle's like, whether they're having regular parasite control. So then we want to move on to ask about their skin history.

So how old was the animal when the clinical signs first started? And this is very important because allergies we know will start generally in dogs from 6 months to 5 years of age. If this dog's suddenly presenting to you at 10 years of age, it's unlikely to have an allergy unless they've only just rescued it and they're unaware of its previous history.

We like to ask, has it been a constant problem? Does it wax and wane in severity? Some clients will report that this is a problem every summer, which again gives us more of a feeling that this might be a seasonal allergy problem if it only happens every summer.

And then we asked them to describe what the first clinical signs were and how the disease has changed. So bear in mind, some dogs may have had skin disease for many years. So by the time you're seeing this patient, there may be a lot of secondary change to the skin.

It could be black, it could be, like canified, very thickened, look more like elephant skin, if you picture the sort of chronic, allergic dog. So, ideally, we want to know what happened first. And it might be that the first clinical sign was just pruritus.

They were just itchy. And when they looked at the skin, it was a bit red. And then maybe they got spots.

And clients are very good at describing lesions and how they evolve because they've not had to learn them in a textbook fashion like, like we do. But it gives us quite a lot of information. And then we'll always ask about the itching.

So, where are they itching? How much are they itching, and all of these things give us important clues as to what's going on. I get my clients to score the itch out of 10, because then that's a measure for me on when they, I see them back, whether the dog's improved or not.

And so, not every client will score the itch in the same way. So sometimes they'll tell me it's an 8 and you look at the dog and you think, no, it's not, but at least they'll be consistent and they act as their own control. If you really want to get an official puritis score, there is a scale available that you can get off the internet.

So there was a study done on this owner assessed puritis scale. So you can download this off the internet free access and then get the owner to just mark on how severe they feel the itches, and you could do that for every, for every visit. It's also useful if you're seeing a dog that's had a chronic problem or been itching for a long period of time, to ask if they've had any treatment that has benefited them.

So, have they, do they stop itching when they have steroids? That's really important information. Do they stop itching when they have antibiotics?

Maybe the infection is a big component of their skin disease. And they have they got a seasonal pattern to the itching, because obviously, that would lead us more to think more of atopic disease than it would food allergies. Possibly parasites, depending on, the clinical presentation.

Once we've got all our history information, we'll then move on to examine the patient. So we always do a general physical examination to examine the dog all over, before we even look at the skin. Sometimes you might notice that your patients have got a lymphadenopathy.

It's really, really common for dogs to have enlarged pre-scapular and popliteal lymph nodes if they've got any sign of skin infection on their feet, for example, or demodex on their feet. Pyrexia is pretty unusual in dogs presenting with pruritis, unless they've got, autoimmune conditions or something else going on. So generally, pyrexia isn't something that we would observe.

And then once we've done our general physical exam, we'll move on to examine the skin. So we always examine our patients from nose to tail. So we roll them over, we look at their belly, we look at all 4 ft and try and keep a record of what you can see.

It's important that you can recognise the lesions that you see because to differentiate which are primary lesions caused by the disease and which are secondary lesions that have been caused by the dog traumatising the skin. So for example, can you see papules and pustules and. Crusts or epidermal cholets, which might lead you to suspect this dog's got a apioderma or a skin infection.

Is the skin greasy? And we don't just focus into, if you look at the picture at the bottom right of your screen, you'll see this dog's clearly got a well demarcated area of alopecia on its flank. And this boxer dog did have seasonal flank alopecia, but it's actually presenting to us for pruritus.

And obviously, that's completely unrelated to it. So it's important to examine the dog all. Over, and when we examined this box all over, she had red greasy feet and quite a marked malothheia proto dermatitis which explained her licking and chewing at her feet, which is what the owner was more concerned about than the alopecia.

So, as I said, we examine all of the skin. So in these pictures, this is a, an allergic box of dogs. So you can appreciate that the muzzle's quite erythematous.

She's got some periocular alopecia or thin and thinning of the hair. She's also got quite pink ears. It's always tricky and white dogs because they always look, pink a lot of the time if they're excited or stressed at the vet or the vet surgery.

Then if we look at the feet, you can see that there's some hair loss. You've got some quite marked saliva staining around here, so, quite a lot of brown discoloration to the fur, but the skin's red and you can also appreciate that it's quite thickened compared to what you would normally expect. That's not just the fact the hair's missing and the skin is actually quite thickened from constant irritation.

And it again, just examine everything and describe what you see. So these two dogs both have sarcotic mange, both very different clinical presentation. So the dog on the left, you can imagine you can picture that they're thinning of the hair on the pinny.

You can also see some redness on the elbows. And that's sort of a classical presentation for sarcoptic mange. The picture on the right hand side, you can see is a German shepherd's bottom and tail, very thickened, lots of honey coloured crust, and this dog also had our Coptic mange, but it was confined to that area.

So we're presented with our itchy dog, we've done our clinical examination. We've had a good look at the lesions, we know the dog's history. So how do we go about working out if this dog has atopic dermatitis or not?

The first thing we're gonna do is rule out ectoparasites as a cause. For the itching. And there are lots of simple in-house tests that we can do to examine the the patient for ectoparasites.

We don't need to send any of these samples away apart from the blood test, but we can do coat brushings, we can do hair plucks, skin scrapes. Sarcoptes is tricky to diagnose, so sometimes we will send blood for serology, which is the dogs have clinical signs for more than 3 weeks, can be a good way to determine if they've been exposed. Or we can think about trial treating them for sarcoptic mange and fleas to eliminate that as a cause.

So we're just gonna have a chat about some of these diagnostic tests. So coat brushing. I'm not sure if you're going to be able to see this video or not.

So basically, a coat brushing is a much more sensitive way of us being able to look for evidence of fleas in our patients. So it's especially good for cats. But what we'll do is gently brush the dog's coat either onto a tabletop, or you can do it just put a bit of paper underneath the back of the dog and brush the coat.

So you've got all the scale and loose hairs. We would then collect all that material together into a pile, on the table, and we would lift the hairs out of that sample because we're not interested in the hairs in this sample, we're interested in the scale and scurf that's left behind. So when you remove the hair, you're left with some scale and scurf.

And then you can collect that material either using some sellotape. And just pick it up with the sellotape and stick it down onto the glass slide. Or some people prefer to use some liquid paraffin, so just to Scoop up the material onto a glass slide with some liquid paraffin.

I tend to use sellotape because it's, it's quicker and easier and less messy. But yeah, so collect your material on the sellotape, then stick that down on the glass slide, and then you can examine that under low power. With the microscope.

So to see what we can find, if we can find any evidence of parasites in the hair coat. So things that we might see, so we might see some flea dirt so as you can see here, so. The bright red sort of comma shaped crystalline substance is is flea dirt.

So that gives us evidence of fleas. Often it's a really good way to motivate your client to start using flea products, because this is something you can't see with the naked eye, but it does give us evidence that fleas have been present on that animal. So it's really, really useful, especially useful in cats because they can be really hard.

It can be hard to demonstrate any evidence of fleas on them. But if you're seeing flea dirt in your coat brushing, then you know that fleas are present. You can obviously do the wet paper test, which I'm sure most of you are probably more familiar with, but it does, it doesn't pick up the microscopic amounts of flea dirt that you would see on a coat brushing.

So in my personal opinion, I think the coat brushing is a better test if you're examining an itchy dog. The other thing we might see is this little parasite here with a nice waist. So this is Klatella.

This is the parasite that causes walking dandruff. So you can see here. You might see eggs as well.

Sometimes we see flea eggs in the coat as well. But this again would help us diagnose whether those parasites were there, and whether or not they needed to be addressed. Another test that we can do to look for parasites is we can do a hair pluck.

So this is a really useful test for seeing what's going on at the base of the heads. So we'd get a glass slide, we apply a little bit of liquid paraffin to the slide. And then with our we'd label the slide and then with artery forceps or our fingers, we would pluck some hair from lesion or skin to to add onto the liquid paraffin.

And then we would examine, put a cover slip on and examine that under low power to look for evidence of parasites and also to examine the hair shaft itself. Generally, if you're taking these samples, it's if you're gonna take 3 or 4 different hair plucks and you're putting them all on the same slide, try and lay the roots and the tips. That the hairs in the same direction because it'll just make it easier for you when you examine them.

So once the samples on the slide, you'll add a cover slip. And then you'll be able to look at it under low power using the microscope. And the things you might see.

You may see some demodex. So Demodex lives in the hair follicles. They can cause pruritus.

When I was a student, we always taught modicosis isn't itchy. It's not true. So lots of dogs with Demodex can present with pruritus and red inflamed skin.

So you could see the demodex mites, you may even see some of their lemon shaped shaped eggs. And the other thing you're able to do this test is to examine the stage of hair growth. So whether to tell whether it's a growing hair or hair in the resting phase.

So normal dogs should have a mixture of hairs. This is an allergen hair you can see here, and you can see some debris down the hair shaft, and this is what we call a follicular cast. So that tells us that there is some inflammation or irritation going on in the hair follicles.

So you may also see those follicular casts if you've got dogs with lots of bacterial skin infection. The other test we can do is the skin scrape. So this test is really the test I would choose to look for sarcoptes.

Mainly I tend to use hair plucks if I'm looking for dematocosis, but if you've got very thickened skin, then skin scrapes are certainly a useful test to look for the mic. So again, you're gonna put some liquid paraffin on a glass slide. And then you're gonna find the area you want to sample.

So if you, if it is very hairy, a lot of our patients obviously aren't, but if it is hairy, you can trim some of the hair away with scissors. You don't really want to clip it with clippers because you want that honey honey coloured crust there, because often if you're looking for sarcoptes, they live under that honey coloured crust, so you don't want to remove that. So you're gonna apply some liquid paraffin to the skin.

And then you're going to start scraping. So you may be the lesions you might be scraping would be honey coloured papular, honey coloured crust on a papular dermatitis, or maybe some commodones as we've got here. So you can see some sort of pigmented commodones.

And then you would scrape in the direction of hair growth and then scoop up that material and place it on a glass slide with some liquid paraffin. And you carry on scraping until we get what we call capillary use. So capillary use isn't a lot of bleeding.

It's a very tiny little spots of blood, just as you break the surface of the skin. So you, you, if you get lots of blood in your sample, you're probably scraping too, too much. And all that's going to do is make it your life difficult when you go to examine that sample.

It's worth remembering that if you're doing skin scrapes in the hopes of finding sarcopies, you've, you've got a 50% chance of finding them if you scrape 88 sites on that patient. So it's not a very reliable test. If the scrape's negative and you're highly clinical suspicious, then I would definitely think about trial treatments.

For those dogs or maybe the sergy. So once you've got your scrape, you're gonna put the cover slip on and then you'd examine that sample under low power. So these might be what you could see.

So you may see demodex on skin scrapes. It's certainly a useful way to see them. And you could see Sarcoptes mites.

So these pictures are taken under the from the microscope. And you may also see eggs, and with sarcoptes, one mite, one egg, or some faecal pellets, as you can see here, would be enough for you to make a diagnosis of sarcoptic mange. Sometimes eggs can be difficult to identify.

So if you see something this shape and you're not sure if it's an air bubble or an egg, if you gently tap the surface of the cover slip or apply gentle pressure. An air bubble will distort, but the egg will remain the same shape. So that's a useful tip if you're not sure what you're seeing.

And then we've said before that if you suspect Sarcoptes. I would certainly think about doing serology or trial treatment. We've got lots of available licence treatments that are very effective.

So, and you're probably going to want to instigate parasite control for fleas anyway. So if they're not on something that kills sarcos, you could just change that product to help eliminate that from your, to rule that out as a diagnosis for the itching. So we've got our dog, we've now ruled out parasites, they're definitely not causing the pruritus.

So the next thing we need to do is rule out infection. I think the most important thing I ever learned as a resident and as a clinician is that the infection is itchy. So yoderma is really itchy and so is malahesia dermatitis, and it could certainly for some dogs, if the client's grading them as 10 out of 10 itchy, just by treating their infection, you can make a significant improvement to their pruritus without doing anything else.

The clinical signs that we see for infection can be very suggestive. So this is a dog with acne. So you can see all the frontals on, on the chin there.

So this dog got a deep pyoderma in its chin. But getting cytology from the lesions either if they're moist by doing an impression smear or by taking a tape strip can also be extremely useful for us to work out exactly. What's going on.

So just to talk a little bit about pyoderma, so we do see pyderma as a common complication in a lot of our atopic patients, and it can increase their level of pruritus. So this is sort of a classical presentation. So often you will see lots of papules, and crusts and, epidermal colorettes, but the circular rings of crusts in most dogs.

Often it's on their ventrum or on their medial thighs. It's often where you see lesions. So here's a nice epidermal cholera.

So that's basically a pustule that's ruptured. Although pioderma does cause pustules, generally we don't see them because they're fragile and they rupture rapidly, which is why we probably see pacules, so little raised red spots, and these epidermal colorectal rings of scale. Once the pustule's ruptured, but if you do cytology from any of these areas, you will find evidence of neutrophils and coccoid bacteria.

Short-coated dogs like to do things a bit differently, so you may well have seen this. Often people get worried that these dogs have got ringworm, but often they, they do just have a bacterial infection. So they don't really get the big rings of scale, but they get sort of patchy circles of alopecia on their trunk.

So this dog basically just has a superficial pyoderma, the same as this dog over here, but it, they just present in a very different way. So it's just worth bearing in mind that in short-coated dogs that can be a clinical presentation for pyoderma. And if we took some psychology, we might find this.

So if you look at the picture on the left, you can see lots of degenerate neutrophils. So all of this purple streak is what we call nuclear streaming, and you can imagine that these cells here were neutrophils once. And then there's lots of coccoid bacteria and some of the intracellular.

So we know that we've got a bacterial infection there. The most common bacteria that causes poderma in dogs is taitude intermedius. So that's normally what we see.

Rarely, we might see this presentation with lots of rod-shaped bacteria, and that would be very unusual. And if we were seeing rod-shaped bacteria, we'd certainly be thinking about sending a swab away for culture and sensitivity. Malasthesia can present in many ways.

So again, it's a big complicating infection factor in our patients with allergic skin disease. So the skin often will look inflamed, it will be greasy. If you see the cases when they're really chronic, you certainly get this sort of hyperpigmentation due to the chronic inflammation and thickening and lichenification of the skin.

So this is a dog that's probably had malathessia dermatitis for about a year, and you can see that there's hair loss. The skin type of pigmented. You can appreciate that probably looks a bit like elephant skin.

They can get the yeast anywhere on their skin. In between the toes is a really common area. We see it in the groyne, any skin folds, facial folds, but it can be a significant cause of pruritus for a lot of dogs.

And again, sometimes just managing this will improve the dog's clinical signs. It was always going to be occurring because there's something else going on, but management of this is important. And if you take some cytology, so generally we would use tape strips from these patients.

You can see large numbers of these peanut, footprint, budding yeast, associated with some skin cells or squams. And a lot of people ask how many is abnormal. And the answer I was always told was if the dog's itching and you're finding them, then they're probably abnormal and you need to treat them.

So a lot of the textbooks say you need to see more than 5 high power fields. But sometimes we only see 2 or 3. And if you've got a dog that's hypersensitive to that yeast, they can have quite marked pruritus because of it.

So I think it's worth bearing in mind that I take strip a lot of dogs. With skin disease and we don't always see the yeast. So generally my feeling is if I see them and the dog's it, that they probably are a significant clinical problem that needs to be treated.

And the way in which we can do that is by using medicated shampoos. But what about culture and sensitivity testing? So it's quite expensive.

Do I do it in every case? Absolutely not. So we know that probably 90% of the yermas that we see are caused by sta food intermediates.

So if I take stripper dog on first presentation and see cocky and neutrophils, generally, I will make an empirical choice of antibiotics and treat that condition, along with oral antibiotics and, and topical therapy, if the client can, can do that. If we're seeing a dog that's had lots of courses of antibiotics, and we're still seeing cockeye on cytology when it's referred at that point, we may think about sending, we will, we would think about sending a swab for culture and sensitivity because we are seeing some methicillin resistant fast food intermediates and MRSA and some of our dogs these days, unfortunately. So I think if it's the first presentation, then I would just treat, but if it's recurrent.

Or it's not improving on the treatment you're given, and certainly a swab of culture and sensitivity would be indicated. We never send a swab culture if we see yeast on cytology because it's not going to give us any more information than we already know from our cytology. So we don't do sensitivity testing for yeast routinely, and it's not gonna change our treatment.

If we ever see rods on cytology, we'll always send a swap for culture, because they don't have a very predictable sensitivity pattern and so we want to make sure that if we're giving this dog oral antibiotics, it's going to be effective. So we've talked about the sorts of infections, so how are we going to manage those. So often if dogs have got superficial pioderma with papules and it's quite extensive, then systemic antibiotics are going to be required.

Generally, my first choice would be cephalexin, . It's usually fastid intermediate normally responds very well to that treatment. And so we're treating with systemic antibiotics.

We would always combine that with a topical therapy as well, providing the owners can do it. Some clients are concerned about the costs of shampoo, and they are quite labour intensive. So sometimes if you get an elderly client, they just can't physically.

Both their 60 kg Great Dane. And so we need to think of other ways around that. So there are now mousses and dry shampoos and things we can use, wipes can sometimes be used, but we should always try and combine our systemic antibiotic treatment.

With some topical therapy if possible. And then some malathhesia, topical therapy will be the mainstay of treatment, so medicated shampoo. The main thing is to make sure that clients adhere to the contact time so they get a good response to the treatment.

So we've now ruled out our infection and we've ruled out our parasites, so, but the dog's still itching. So the next thing we need to do is rule out food as a cause. So how do we diagnose cutaneous adverse food reaction in dogs?

So there's lots of tests available, but the only way we can do it is with a dietary trial. So there's no blood tests that are available, but they're just not useful. So there's been lots of studies to show that they're not useful, including a recent review of them, .

Some people use them to select diets, but they're definitely not useful to diagnose a food allergy. So the only way we can diagnose it is to do a dietary trial for 6 to 8 weeks. We need to get the client on board because owner compliance is the most important thing.

And I know that I'm in a privileged position because I have spent a lot of time talking to clients about diet trials. We can do it either using a home cooked diet, which some clients would prefer, especially with the amount of raw feeding we have currently, some clients prefer to home cook their diet trials. And the advantage of that is you can pick exactly what they have, from your good dietary history.

We can use limited antigen diets or we can use hydrolyzed diets for that purpose. So home cooked diets. So with those, ideally, we're trying to find a novel protein and carbohydrate source.

And as we've already said, the advantages are that we know exactly what's in them. So if someone's cooking fish and potato, we know exactly what's in them. And for some small fussy dogs, they certainly work very well.

I think the problems we have now is that so many novel diets, commercial diets are being produced, it's often difficult to find a novel protein source for, for your patients. I do use quite a lot of corn mince, for my patients because that's generally something they haven't been exposed to. But that people often are fed rabbit or various other venison and lots of other meats.

So sometimes finding a novel protein can be difficult. And the other thing is it can be labour intensive for the clients, so they've got to cook for their dog for 6 to 8 weeks. So whilst they can batch cook for some clients, if you've got a 60 kg dog to Bordeaux, for example, that's gonna be expensive.

And quite labour intensive and your house is probably in the smell of fish and potatoes for quite a long time. Yeah, and obviously they're not nutritionally complete. So should you find that that dog's then Food allergic, you then need to find a nutritionally complete diet or balance their diet so that they can be fed that long term.

Limited antigen diets are the ones that have a novel protein and carbohydrate source. But they're not hydrolyzed proteins, but they're a dry dog food. So people can feed those as they would feed their normal dog food.

So there are lots of different things around. So in some countries they have kangaroo, for example, which would be a novel protein here, but isn't probably that novel, in Australia. But it can, again, be difficult to find a novel protein, and they can be expensive.

So sometimes clients really struggle, and you've got to really work with your client when you're doing a diet trial to try and find something that they're happy to feed. You know, some clients won't feed certain brand, brands of dog food. So you need to find something that they're happy to feed that's palatable to the dog, and that's going to work for 6 to 8 weeks.

And the other option we have is hydrolysed diet. So there's lots and lots of hydrolysed diets around now. They're not always a novel protein, so some of them are based on chicken, some are based on soy.

We've got some fish-based ones, and we've got some very hydrolysed ones like an allergenic, that's based on feather protein. They are nutritionally complete and they are easily fed, and most dogs find them, you know, very palatable. There's the odd dog where they're not thought to be palatable, but they can be quite expensive.

So for some clients, this might not be an option, but generally a lot for a lot of my patients, I do discuss the use of a hydrolysed diet because you do get better compliance with it. So with regard to food allergy, when we're working up an itchy dog, and we often get asked, what's the best diet to use? Do any really get better?

And is it worth doing a diet trial? So the best diet to use is one the client's happy to feed, that they can afford, and that the dog will eat. And there's no 11 size fits all.

That's really got to be time spent discussing that with the client. And yes, they do respond, do respond to diet. If you don't look for food allergy, you won't find it.

So, I would say probably 10 to 20% of my allergic dogs that we work up have a food allergy or diet at least plays a part in their allergic skin disease and significantly reduces the amount of additional anti-inflammatory therapy they need if if diet plays a role. So it is worth doing. I think it's how you sell it to clients makes a big difference as to your uptake.

Of whether they're going to pursue a dietary trial. So this is my emergency I saw as a resident. I often use this picture because I never thought food allergy could look this bad.

But this dog was admitted out of hours because of its intractable pruritus. And this was just two days later, just by changing its food and giving it some antibiotics. So it's quite a massive improvement.

I think skin's quite amazing that it can do that. And that dog ended up having one dose of oral prednisolone. And then just a change in diet and was completely normal two weeks later.

So food allergies can certainly be very dramatic and they can be very severe. It's really important at the end of the dietary trial that you rechallenge the patients because you want to know if the improvement you're seeing is due to all the other things you've done. So changing the flea control, treating the infection, or whether it's really true to the diet.

Obviously, some patients' skin disease will improve just because you've improved their nutrition, from putting them on an exclusion diet. So you must rechalenge them. Generally, if I'm re-challenging my patients, I'll get them to feed everything the dog ever had over a period of 2 weeks, so that we can see if the dog flares up.

And I'll then take the time if it flares, and we know it's a food allergic patient. We then take the time to find out what they can and can't have so that the client can use treats. And perhaps find a cheaper dietary alternative for long term use.

So now we've gone through, we've ruled out parasites, we've ruled out infection, we've ruled out food. If that dog is still itchy, with no infection, no parasites, and despite the dietary trial, and it's got compatible history and clinical signs with atopic dermatitis, then we would make that diagnosis. So we would conclude that the patient had atopic dermatitis.

The compatible history and clinical signs would be the correct age of onset. Feet and face affected? Does it have recurrent infections, recurrent ear infections, recurrent yerma, all of those things.

And once we've done that, so we would diagnose the patient as having atopic dermatitis. So it's really important to realise that there's no test that's gonna diagnose this disease for you. It is a diagnosis of exclusion and you are actually the best.

The best person or the best tool to make this diagnosis in your patients. So you have to rule everything out and you do need dedicated owners. It's not something.

Some clients don't want to go down that route and they might be happy just having the steroids to control the itch, but you do need dedicated clients to be able to see that. So once we've got a diagnosis, then we might think about allergy testing. And I think there's a lot of confusion over to why we allergy test, you know, some people think we allergy test to diagnose atopic dermatitis, and that's not correct.

So we don't do allergy testing to diagnose atopic dermatitis. We try and allergy test to either identify allergens to avoid, which as we're all aware of seeing house dust mites are the most common allergen, that's near on impossible, or to formulate some allergens specific immunotherapy for the client. So if you've worked up your patients, you've concluded it's got ATP.

And the client has no money or doesn't want to pursue immunotherapy for 10 months to see if it's going to work or spend the money on allergen testing, you don't have to do it because you can diagnose this disease clinically. And I think that's really important, because it's not an expensive condition to diagnose. It's time consuming, but it's not, doesn't involve lots of expensive tests.

So the allergen testing is often quite expensive, as is immunotherapy, although long term, that may work out cheaper for managing some patients. But I think it's really important that you realise you diagnose this disease without doing any allergy testing. But if we are going to allergy test, the other question we often get asked is, Do we use an intradermal test or do we do serology?

And the answer is you can do either. So if it's a good reliable allergens specific IGE serology test. You can, you can do that test if you've got access to intradermal testing or you're, you're friendly with your local dermatologist who does it, and intradermal testing is also useful.

And it's important to realise that, you know, a proportion of dogs won't have any results on allergy testing. That doesn't mean they don't have atopic dermatitis, that just means the way in which we're testing them. Hasn't shown the results, so we're not testing the right thing.

The same situation happens in people. So there's a proportion of atopic people that don't have any positive results on allergy testing. And it's really important you discuss that with the client before you spend their money doing allergy testing, because otherwise you get sort of deflated owners who think, well, it's not allergic, there's no positive results, and that's not true.

So I always warn our owners that we can allergy test, but we might not get positive reactions. That doesn't mean. That their dog isn't atopic, it just means.

That we haven't been able to identify the allergens and we won't be able to pursue immunotherapy. So I think that's really important. And some dogs will react on an intradermal test and not the serology and vice versa.

So sometimes we end up doing both these tests in our patients to try and identify the responsible allergen. Because they want the client so keen to pursue immunotherapy. So I think just because you've had negative results on a serological test, don't rule out the fact that the client really wants to do immunotherapy, it may well be worth doing an intradermal test to see if you get any positive results on that.

So I think making a diagnosis of atopic dermatitis is very challenging. So it's frustrating for the owner, because there's not, you know, we all would like a magic bullet that we could just say to the owner, I'll do this test and they'll tell me if you don't get AP and then we'll be able to go from there. But unfortunately, there is no test.

It is a diagnosis of exclusion. And it's very frustrating for clients because it takes a long time. I think it's helpful if you're working at these cases, if you try and convince the client to be the same vet in the practise.

So that they've got some continuity of care and tell them at the start that this is probably gonna take a couple of months before we know exactly what's going on. We can't take any shortcuts, so We can't just say we won't do a food trial because remember normal dogs will have reactions on allergen testing. So if you don't do a food trial, and you just allergen test and say it's got probably got AP.

You may still then have to go back and do that food trial at a later stage either because the immunotherapy didn't work, so you can't really be sure whether that dog's atopic or Because you don't get any results on your allergen testing and then you don't really know what's going on. So you do need dedicated owners who understand the process and you might find having handouts to explain the what investigations to clients might be useful for you. So just to summarise, so parasites and skin infections always need to be excluded as a cause for pruritus, and they're certainly a contributing factor in a lot of our atopic dogs.

We don't want to do any haphazard testing, so just seeing an itchy dog and doing allergen blood tests isn't useful. So we want to work our way through the, through the diagnostic process, ruling things out. And then if we've still got critic dog at the end, then we can conclude it has atopic dermatitis.

We should be trying to do all these tests in-house. So using the microscope in-house and getting familiar with it, not only would it improve your own skills, but it saves the client money. And it's really rewarding, you know, you still can't beat the feeling of skin scraping a dog and finding arcoptic range or demodex.

So if you're not doing it regularly, then please try and do it and look at it in-house. And if you, if you, if you don't want to look at it, try and train up a nurse so that they're, they will find it rewarding looking under the microscope for you and then build your confidence in them. But I think the main take home message is that a logical approach is required to make this diagnosis of atopic dermatitis.

And it's a process of ruling out parasites, ruling out infection, ruling out food, and then if you've got a dog with a compatible history and clinical signs, we can conclude it's got atopic dermatitis. And if there are any questions, I'll try and answer them. OK, thank you very much, Natalie.

That was absolutely brilliant. We don't have any questions so far, but if you do have any questions, please feel free to send them through. Just hover over the bottom of your screen and there's a Q&A box.

Just type your question in there and that'll come through to me so I can read it out to Natalie. Also, if you are leaving this webinar and not joining Natalie on the next one, please remember to fill in our feedback form that should have opened in your browser, just so we can give some feedback to Natalie and also tailor the future webinars to meet your needs as well. And if you do have any questions, please feel free to send them through.

We'll, we'll wait. We've got another 10 minutes until the talk, so please feel free. OK, we've got a couple coming through now.

Let's have a look. OK, so we have one saying most of the CPDs that I've had in this area have said that doing blood tests for allergies is a waste of time. What is your opinion on this?

So, it makes a big difference depending on what you're testing. So blood testing for food allergy is a complete waste of time. Blood testing for environmental allergy, if you're using an allergens specific IGE test, is fine.

There's studies that show, even that have followed dogs up on immunotherapy, and there is no difference between doing that and doing in and, and following dogs that have had intradermal tests and immunotherapy. So food allergy blood testing, don't do it. It is a waste of time and money.

Environmental allergy testing, if you've got your clinical diagnosis and you're using a lab that does allergens specific IGE testing, then that is a useful test to do. Excellent, thank you. And another one, are there any distribution of lesions that would make you suspect atopic dermatitis over CAFR?

OK. So, not really. So, basically, food allergies or cutaneous adverse food reactions and atopic dermatitis can present in exactly the same way.

So you can see lesions in the same places, so they can have recurrent pyoderma, they can have ear infections, the face and the feet are normally affected. And that can happen with both diseases. Sometimes the dogs with food allergy, another thing that might help you differentiate them is they often have gastrointestinal signs.

And if you question owners quite intensely on Deecation habits and things. Sometimes you get some surprising answers. So a lot of owners sort of live with their dog having diarrhoea 2 or 3 times a week and think that's normal.

Obviously, that would raise your index of suspicion for food allergy. Likewise, if they were defecating 6 to 8 times a day. And those are all answers that we get when we question them about, in our general history about their general health.

So I think gastrointestinal signs, is a pointer and age of onset is a pointer. So food allergies. Seem to start more commonly in dogs less than a year of age.

So if you've got a very young dog, it's always worth making sure you exclude food allergy. Excellent. And another question, how long do you continue treatment for sarcotes and is it just until the clinical signs resolve?

So generally, I would use the licenced treatment recommendation for the product that you're using. So normally 2 months, so normally depending on the product you're using, but 2 treatments 4 weeks apart. Just be careful if you're using.

A topical product that isn't absorbed systemically. If you're bathing the dog regularly, you might decrease effectiveness. So obviously, we're lucky now we've got, oral tablet that's licenced as well.

But generally two treatments 4 weeks apart. So I normally said it can take 2 months, but normally after the first treatment within a couple of weeks, the dogs are substant, you know, dramatically improved. OK, thank you.

And what exclusion diet do you use for cats? Oh, good question. So cats are tricky.

Dogs will eat generally, they won't starve themselves. Cats quite happily starve themselves. We, I do use a lot of Purina HA for cats.

They seem to find that very palatable. And there is a Leo-specific hydrolyzed fish-based diet for cats. Which, again, some cats find palatable.

So I would probably go with those ones, but it's a question with cats, there's a lot more trial and error with diets. If they eat wet food, you ideally want to pick, pick a wet-based, a tinned food to use for your dietary trials. So it's a lot of trial and error with cats, much more so than with dogs.

OK. And what is your protocol for MRSP? Oh, it's difficult to, it's difficult to give a, a one-off protocol.

There's some really useful guidelines on. The BSAVA website about dealing with these resistant infections, so generally we would swap them. And then treat them based on our culture results.

But we would use a lot of topical therapy and we'd probably try and use that more intensely. So medicated shampoos, lorhexidine-based shampoos, and rinses would, it would depend where the infection was and what was going on. But yes, generally we try and use a treatment based on our culture and sensitivity results.

But the, the key really is a lot of topical therapy, and persistent topical therapy with cohexidine-based products generally. OK. And would you ever use oral malashesia treatment?

And if so, which one for dogs and which one for cats? OK. So sometimes we do use oral treatment for malathhesia.

So obviously, it's off cascade, so we would have to justify that. So, I tend to use itraconazole for dogs and cats. There is a veterinary licence, ketoconazole, for dermatophytosis, so that would be another option.

I tend, I would tend to use yroconazole. OK. And how do you stain your sticky tape samples?

Somehow mine do not seem to work very well. OK. So if we're staining tape strips, generally I will do 51 2nd dips in the, in all three stains.

So I know a lot of people tend not to stain, put them in the fixative, but I was trained to do it that way. So, everything gets stained the same way. If the sample's not working.

And the tape's going cloudy, it probably means you need a different tape. So, Scotch tape is generally the best, but if you've got any cheap, just general tape that's being used in the office or practise office, sometimes they just disintegrate when you dunk them in the stains. So it's really important to have a really good quality sellotape.

Lovely, thank you. We do have a couple more. So I've heard in the past that immunotherapy is less effective in cats than dogs, but I personally haven't used immunotherapy in cats.

What's your experience in this? My experience in cats is probably the complete opposite, but it might just be that we don't see as many cats and have it on immunotherapy. My feeling is the cats I put on immunotherapy do very well.

And But I think the studies are a lot smaller than in dogs, and I think if you've got an itchy cat, we're so limited with treatment options for them that I would always, if you're going to go down the root of allergy testing, then try immunotherapy. Some cats do really, really well on immunotherapy, so it's definitely worth trying. Lovely.

And what about using Atopica or Aperquil for very itchy dogs with upset owners? Could you use them in short bursts only while on a diagnostic path? Absolutely.

So the most important thing to win your client over is to get that dog comfortable. So I will very often, often if they've got a lot of infection, I will treat the infection. First, and what I normally say to clients is.

I'm not going to give you anything to stop the itch, because I want to know how much that itch is impacting the infections making the dog itch. So what I normally say is send them away with their antibiotics or their medicated shampoo and say, if there's no improvement in 3 to 4 days, ring me, and then I would prescribe an antipyretic agent. But it's very rare that that happens.

But certainly, if you've got a dog that's itching and your diet trialling and it's got no infection, then absolutely I would give it a short course of Apaquil, or steroids to make it comfortable. So at the end of the day, if it's getting towards the end of the diet trial and you can't withdraw that medication. The dog's not gonna have a food allergy.

So, but yes, make your patients comfortable when you're doing a diet trial because you'll get better cooperation from your clients. And in just a couple more. Do you use hippie scrub for bathing of feet to keep costs low.

I was once told 1 in 40 dilution for daily foot dips. So you can use hippy scrub. I haven't, I don't normally get them to dilute it, so I normally get them to put it on concentrated because that's 4%.

And we know we want 3 or 4% chlorhexidine to kill the infection. So I'd get them to put it on and then rinse it off, after, you know, 5 minutes contact time. The problem with it is it can be irritant and very drying with prolonged use, so it's fine for a short period of time, but long term, it may not be the best.

Option. So you want to make sure that the patient's not gonna get irritated by it and make sure that it's rinsed really well, but yes, to keep costs down, absolutely. Lovely.

And you may have just answered part of this for the next one. So is it OK to do a 33 week antibiotic and shampoo, skin scrape and parasite control and exclusion diet at the same time? And if the dog is very pruritic, do you use Apaquil or in short term or steroids?

So yes, it's fine. So often we will routinely see patients that have got infection and haven't had parasites excluded. So we'll put them on, we'll put them on parasite control.

We'll treat their infection. And as I say, normally I'd see if that improves things for a few days before I prescribed anything to stop the itch, because it's really important to know if the in how itchy the infection makes some dogs, because some clients will grade their dogs its 10 out of 10, and then only 2 out of 10 after you've treated infection. And that makes, makes a big difference how you manage that case long term, because you know that actually keeping that infection at bay is going to be a really important part of managing that dog's disease.

Whether I use Apaquel or steroids, often that depends on the client. Some clients are very anti-steroids. I'm quite happy to use either.

Sorry, that's sitting on the fence of it, but it does depend. If there's a lot of inflammation, if the skin is very, very inflamed, I'll often opt for steroids. You know, if the feet are very thickened, for example, or the ears are affected, I'll opt for steroids over Apaquel.

But both do a good job of controlling the, the itch. Lovely, and we have time for just another few questions before we go on to our next webinar. I've heard that there is an increased risk of injection, fibrosarcoma in cats and immunotherapy.

Is this true? As far as I'm aware, that's not true, but, and I've certainly never come across it, but I wouldn't know without researching the recent literature, but it hasn't put me off using it in cats, and it's not something that I'm aware of as being a risk factor in cats. So I, I would have to double check the recent literature, but as far as I'm aware, that hasn't been reported.

OK, and finally, is there a tablet licence for saroptic treatment? Yes, so Symparica is licenced, which is Saulana is licenced to treat, sarcote. Lovely, and that's the end of all the questions you'll be glad to hear.

So many of them. Thank you very much to all of our listeners. If you're staying on to listen to the next talk from Natalie, stay put.

If not, thank you very much for listening and thank you, Natalie, for all of your time and for answering all of those questions.