VETgirl On The Run
Managing Chronic Allergic Skin Disease in Dogs with Dr. Tom Lewis, DACVD
Today's federal podcast is sponsored by Alenko, a global animal health leader Alenko is committed to improving the lives of pets and the people who love them. We are excited to be a leader in the field of veterinary dermatology by providing cutting edge education as well as innovative products for allergic itch and otitis to veterinarians. Hi, Vekrel here today and super excited to speak with Dr. Tom Lewis, who's a board-certified veterinary dermatologist and you guys know I love talking to dermatologists because you know I'm an idiot when it comes to dermatology. Now Dr. Lewis, thank you so much for joining us for today's Vekrel podcast. Well, thank you for having me. All right, so before we begin, do you mind just giving our audience a little bit of background about who you are? Do you mind telling me a little bit about yourself and your career? Where you trained? What you do? And how dermatology for animals came to be? Yes, you know, I'm an Arizona native, I graduated from Colorado State University in 1986, which is probably before the majority of your listeners were born. I went into private practice for a few years found I really loved skin. I was able to do a residency in private practice. I finished that in 1991, finished my residency in passports and started dermatology clinic for animals and then realized there was not enough work for a dermatologist in all of Arizona. So I had to start flying to Albuquerque, El Paso, Salt Lake City, and I would usually fly, take the day, fly there on Southwest flight, get home in time for dinner. And over time, I got busier. I finally reached the point I was able to hire Dr. Kim Coiner. And she joined me for a number of years and we were still this is busy. So we hired a resident or started a residency program and it just kept building and it reached the point where we were filling needs. You know, when we went to Utah or some of the various satellite clinics, we were the only dermatologist there, sometimes the only specialist in the state. And so we felt good to be helping those patients. But then we also started having really wonderful young doctors wanting to do the same thing. And we had the opportunity, the vehicle to allow them to do that. And that's how our business just grew. We've did end up buying lab practice in California dermatology for animals and I just love the name D4A. And it's been just such a wonderful career. I love this profession. I love my specialty and would do it all over again in a heartbeat. Wonderful. Well, thank you so much for all that you do because, you know, dermatology can be really frustrating for a lot of general practitioners and emergency critical care specialists such as myself because I feel like in those two weeks in vet school, there's so much to know. Now I did want to ask, what are some of the biggest challenges you face as a dermatologist? You know, I would say that there's the big three for probably most of my colleagues. Starting with chronic otitis, you know, we all see these cases, even in emergency. And it's my opinion and experience that I feel we spend too much time and emphasis focused on the microorganisms and not enough focus on the underlying cause. And I'm certainly not saying that we ignore the infections and the microorganisms involved. But if we don't accept the challenge of finding that allergy, because it's usually an allergy. And if we don't start the process of working that up and dealing with that, with all that inflammation at the allergy's triggering, it just progresses and the infections involved become more and more established, more resistant, more biofilm formation, more secondary and anatomical change with stenosis and the ceruminous gland hyperplasia, which can make it look like there's cauliflower growing in an ear, all because we're not aggressive enough finding the underlying cause and dealing with it. Second on that list, and it's the same process in a different location, the chronic poto dermatitis. You know, a date does not go by that I don't see a bulldog of some flavor, French, English, or American with poto dermatitis. You know, some of the same process occurs that they get progressively worse, we're again throwing antibiotics at them, and in a day and age of resistance that's just making the problem worse, at least it's making the problem of resistance worse. And ultimately, we get end up with, we don't have effective options for the feed, the feed become more swollen, we think about the pharyngeals and the nodules and the draining tracks and on it goes, and the part of the challenge is that some of the popular antiporitic drugs that we've had over this last decade, they're just not effective at blocking that kind of inflammation. So we're forced to reach for drugs like corticosteroids and cyclosporin, because those have a more potent impact on the deep inflammation, at least that's by the time they get to me, that's what we have to do. So that's probably number two, the third one I've already touched on, but it is MRSP is the multi drug resistant staff infections that we see, I was just counseling or talking with my resident, she's got a case of the dog has both ringworm and resistant staff, the only two options we have are rifampin and chloramphenicol, and it's just a mess. And it's a deep infection, so the thought of being able to successfully manage that topically is daunting and going to be a challenge. You know, I was mentioning how I'm terrible with dermatology, but I remember having some cases that came in through the ER that were hospitalized in ICU. And when I was doing exams, there would be like very little discharge and disgusting otitis. And some of these dogs, and obviously they were there for something more emergent, like a hemo abdomen or, you know, a foreign body. And I remember the tech laughing at me, they're like, why are you cleaning ears right now? Like the dogs, you know, he's, he's just being stabilized. I'm like, I cannot believe that owners don't even notice this, right? It's like puss dripping out of the ears. I always took my punishment for being so bad at dermis. Unfortunately, all my pets got inflicted with a dermatological disorder, so I'm much more empathetic. And, you know, that's an ear that's just not going to get better without cortical steroids. We just have to put out that fire with cortical steroids. Yeah. What are some things you feel are important to evaluate, or more importantly, not to miss when presented with an itchy allergic dog? Well, the first one to not miss, you know, it does cause allergy, but we certainly don't want to miss the parasites. And I practice in an area where we don't have fleas, but we do have scabies. And we certainly, the whole world has demodex, and we still see those cases in areas where good flea control is being utilized with one of the various isoxazolines. There's probably going to be less risk for the parasites. Nonetheless, that's the first thing that you don't want to miss. Next thing to not miss, one of my favorite lectures to present, I titled Allergy Memickers. And it's basically a big PowerPoint of, it's a show and tell of some of my various diseases that are not allergy, but cause varitis. So we're talking about dermatophytosis and we're talking about sebaceous adenitis, pemphagous foliation and T-cell lymphoma. And even though those are not diseases that we see every day, they are diseases that cause the itch. They are diseases that will fool veterinarians. And in preparation for this podcast, I actually decided to, I mean, I know what these diseases look like. I should after this many years, but I went to Google and just looked at Google images and Google sebaceous adenitis and just, my screen was filled with examples, good examples of sebaceous adenitis. And I get it, you know, if you're not seeing skin every day, you're maybe not prepared to make a diagnosis of sebaceous adenitis based just on the physical exam. But the point I would make, if you've seen enough pictures of those diseases, you're going to recognize when that itchy dog walks in your door, you're going to recognize this may not be an allergic dog, this may be something else, then maybe the appropriate thing to do. Instead of destroying a bunch of anti-paridic drugs at this dog, it's time to do a biopsy. So that's something that I don't want to miss. And today, we still see cases that were misdiagnosed as allergic. The case I just mentioned actually had Trico fightin, but he had been misdiagnosed as being allergic. The third thing I really hate the thought of missing, I hate the concept, the thought of putting a food allergic dog on drugs his whole life. When we really, that's analogy we could identify and avoid. So I think it's important to know some of the subtle but real differences between a dog with atopic dermatitis versus a dog with a food reaction or food allergy, or if the currently goes a cutaneous adverse food reaction, but we'll just call it food allergy. And because there can be some clues, not full proof, but some distinguishing differences, you know, the food allergic dog may not be as responsive to the drugs. A food allergic dog won't have his paritis, won't be seasonal. It may have a pattern of urine, rares. It might be a dog presenting before the first year of life or after eight or nine years of life. And none of that is full proof and none of that rules out atopic dermatitis. But when I hear about those things, when I hear about the itchy dog who's having four bowel movements a day, that catches my attention because that's a signal that we may be dealing with a food allergy. I had a patient once, he had his name tag and on his name tag, it said, "I like to poop." I'm looking at that name tag. I mean, who does that? That was a food allergic dog and he got better with a hypoagenic, with an elimination diet. So a good place to learn that, the things I just rattled off, you know, Dr. Ralph Mueller and Teri Oliveri have published a series on food allergies and it's free, open access. It's the BMC veterinary research. And you Google their name and food allergy and BMC, you'll go to those and they, I think there's 12 little small articles with some examples and so forth. Excellent resource. I would also make a plug when you're doing food trials as more and better options have come our way with prescription foods. I mean, I remember the days when we had to home cook lamb and rice and I know that we have better options today. And so some of the better hydrolyzed diets, I think, when we use those strictly, when we are coaching our clients to avoid all the extra treats and supplements and doing a food trial adequately in six to eight weeks is long enough in my experience with rare exceptions and maybe even pre-treating with a little bit of prednisone to put out some fire or twice daily apocle to put out the fire until the food trial has a chance to work. When we do that, we find that food allergies are not as rare as some claim to be. And it's my experience and opinion about 30% of our allergic dogs have a component that's food driven. And sometimes it's both food and environmental. And when you take food out of the picture, the leftover environmental allergy is easier to manage. I think those are probably some of the most important things to not miss when you're dealing with that angida. Thank you so much. You know, we're all taught that, right? Like as a differential, those big three, like the food allergy, the phleology dermatitis, the atopic skin disease, but man, is it clinically hard to diagnose and dissect out, right? It's harder than it looks. It's the idea is, but with practice and with the little study and just again, knowing there are some differences and when you can recite those differences to your client, and these things take time, but when you can recite that to your client, it gives them some confidence that maybe this is, in fact, an appropriate thing. Maybe it is worth not giving my Frenchie a bite off my table. Great information. You'll be glad to know that one of your Australian colleagues was yelling at me. I just randomly met this dermatologist at a conference. And of course, we were talking about my young people and he was graciously yelling at me about my terrible food trial since the mailman was like slipping milk bones down the mail shoot, which like pops into the living room and I couldn't control it. So, yes, all right. Now, in terms of therapeutic options for allergies, there are a handful of key players. What else might we need or want in our dermatology toolbox? You know, we've now, this year, we celebrated Apple Quel's 10-year anniversary since its launch. When I got out of that school, we had steroids and allergy shots or bust. We didn't even know about cyclosporin. And I remember reading a article from Dr. Oliver about reusing cyclosporin to treat allergic dogs. I thought he had lost his mind. It seemed so overkill, but we've had Apple Quel and an Apple Quel was such a game changer. You know, I don't doubt that it's changed a lot of millions of dogs. And then I see the failures, you know, that's the ones I see. And so we clearly Apple Quel didn't fix every allergic itchy dog. So when I see those patients, those are patients that sometimes require us to reach for drugs like cyclosporin. Cyclosporin has its own pros and cons, though, you know, sometimes it's not very well tolerated. Cyclosporin can with time potentially call gingival hyperplasia. The GI upset, of course, is legend and there's some drug interactions to know about the cyclosporin. And it takes a little bit of time to work. So it's not a magic bullet either. Cyclosporoids, three nice things about steroids, they're fast-working, they're effective and they're inexpensive. The problem with the corticosteroids, of course, is there's more side effects. So there's limits on how much of that we can use safely. You know, a side-of-point has had a great impact and it's got a very nice niche. I mean, I give my allergic dog side-of-point shots, but side-of-points blocking itch, but it's not blocking inflammation. And you know, what we're missing at this point is maybe just more or better options of a little bit of what we have. You know, if we had a product that could block the inflammation to an even better, even more thoroughly, quickly without having some of the adverse events that we can sometimes see with cyclosporin and corticosteroids, I mean, there's still room for improvement or more need and that's one of the needs that I see. All right, now what are some key points to inform pet owners about when managing chronic allergic disease, like do you have any general tips on communication? I feel I've actually worked on my skill of communicating with clients and I love it when they say that makes sense. So one of the things I try to really reinforce with clients, and again, I'm seeing the special lens. I'm seeing the worst of the worst, but I remind them and try to teach them that this is something we're going to control. We're not going to cure your allergic dog, we're going to try to control it. You know, we're looking for balance, we're trying to balance the drugs and the cost and the safety and the effectiveness and the work club. We read about caregiver burden, you know, it's nice to have them made their dog three times a week, but it's not always at all feasible. So, you know, and I talk about with clients, especially some of the bad ones, the bad patients, not the bad clients, that we may very well need a combination. You know, is there an argument to be made? Is it better to use low levels of two drugs instead of high levels of one? So because by combinations we can get synergy, especially if we're using different drugs that have different side effects, so the side effects don't tend to add up, but the positive effects of treating the inflammation and ditch, we do get some synergy there. So I'm a big proponent of that. And then last point, but certainly not the least, you know, there's an international committee on allergic disease in animals, and I'm not on that committee, but it says a group of dermatologists, I think just dermatologists on that committee, but they have guidelines on how to manage allergic animals and atopic dogs. And certainly one of their five facets of treatment is immunotherapy should be offered when feasible. And, you know, we don't want that to be a forgotten therapy because it's the only therapy that directly that has any impact on the immune system itself, on the immune response, it's the only therapy that tries to make that immune system more normal. And you know, that's a skill also. It took me a decade or more to get clues about immunotherapy. And so with patients or clients who really are interested in that, if possible to refer to a dermatologist, I would. But even if that's not feasible, I would still consider it, I would still promote trying to, you know, using serology and trying to make a difference with immunotherapy so that we don't have a lifetime of drug. Thank you. Excellent point. Now, what are the primary goals of treating dogs for allergic skin disease? You know, my goal is I want what the owners want and, you know, they don't all want the same thing. I mean, they do a bit, but not necessarily. I mean, some of our clients, they just don't want a drug, some of our clients need something very simple and fast and they just don't have the, either the financial or time where with all to do a more intensive protocol. You know, a question that I learned to ask and I wish I didn't know this on day one of my career, but I asked them, you know, what were you hoping for today? And I especially have learned that that could be a helpful enlightening question for me. If I sense I'm getting pushback from a client with as far as what we're talking about, you know, sometimes the answer is enlightening and it sometimes will do what they're hoping for today, you know, assuming it's not harmful for the patient. So that's my goal, but as far as what I want, I want something that's safe, fast, effective, you know, minimally adverse events or adverse effects and most clients are going to want that too. You know, in a perfect scenario, we'd have a drug that makes them better and we have good drugs that does a lot of this now, but if we can make them better, get them to have an itch-free life with the medications. And if it's a young, we're a middle-aged dog. If we have them on immunotherapy, while we're waiting for the immunotherapy to work, we can keep them comfortable with the drugs. I think that that's a definite goal. The better job we are of doing that, of keeping those dogs free of their infections and free of their pododermatitis and otitis, I mean, that's what it's about. If they're not coming in five years later within stage years, we made a difference with our therapies. You know, some dermatologists are starting to use the word remission when we talk about allergies. And I was initially a little bit skeptical of that word in this application, but I've kind of grown to it. And if we can get our patients in remission with immunotherapy plus or minus some concurrent drug where they really have normal lives, they're not scratching. That's really the number one goal we're after. You know, I'm so glad you brought that up because you're right, pet owners probably have very different expectations when it comes to treating their dogs with skin disease or chronic disease. For me, having had that pit bull that had everything, it would be at like 11 p.m. at night. Are you not met? By the third one. I mean. Or just like all the tags that are shaking and rattling when your dog is scratching, even with a rubber band on them, right? So I agree, owners have different expectations that it may be something as simple as that. All right. So you brought up that term remission as practitioners, our goal is to get dogs as close to normal as possible. And again, amazing, amazing tips that you just talked about. Any last tips you want to leave us with when it comes to getting dogs as close to normal as possible? Well, it's repetitive, but I would make sure my parasites were not president and I would make sure the best I could if it was a non seasonal predict patient that I've rolled up food allergy and sometimes you have to do two different food trials to really roll that out. I think that when there's active change in the feed in the years or anywhere, the skin, if it's really deeply inflamed and you think drugs like cyto point are just not appropriate on their own. They may have a place as part of a package, but to use those products, use that product, for example, on its own is just not going to be sufficient. We have to use something to block that inflammation twice daily, Apple can do that. It's been shown to be as effective as corticosteroids and certainly has fewer side effects. Sometimes we will see a bit of a rebound when we go from twice daily to once a day. We see a bit of the itch level go up a little bit and that makes some clients want to give it twice a day. The studies published with apple quail, we get the average dog down from the pee vast or the itch score from zero to 10, gets them to about a four, but a normal dog, we don't consider a dog normal, tell these are about an average of two. So if it's a dog, that's our goal to try to get to two. The question is, with current options of this minute, are we well advised to do we add a little bit of corticosteroid with that? And maybe not in a case to go from four to two, but what if we have to do that to go from each level of six to four or six to three, something like that? I would argue it may be better to use a combination in those cases. I tell clients, and sometimes they don't get this advice wrong now for most of the current veterinarians, but my generation told clients to not overbait their dog. You cannot overbait an allergic dog the more best the better. You might reach a point of diminishing return, but using shampoos that have, you know, they all have chlorohexidine using shampoos that have ingredients to make the barrier better and using them frequently can have a positive impact on allergic skin. So those are some of the baseline therapies of what we do. Love it. You're a germ pro right now. Thank you. Awesome. Awesome content. So helpful again, because all of us see itchy dogs sometimes in our own pets like myself and really, really appreciate all that you do. Thank you so much, Dr. Lewis. Thank you, Dr. Lee. [MUSIC] [BLANK_AUDIO] [BLANK_AUDIO]