Veterinary Vertex

Sedating Horses Safely

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Horses and anesthesia make for a high stakes mix, and the numbers prove it. We open the barn door on a new study of oral trazodone in healthy adult horses that boosted sedation but, at a low dose, unexpectedly increased xylazine requirements at induction. Our award-winning guest, Dr. Emmett Swanton, walks us through the why behind the work, what the data actually say, and how to turn mixed results into smarter, safer protocols.

We dig into the global context first: equine perioperative mortality remains several times higher than in small animals, with most disasters happening during recovery. That’s where behavior, physiology, and pharmacology collide. Could a preoperative oral sedative soften the edges—calmer handling, smoother transitions, less panic? The study offers a nuanced yes: trazodone clearly increases calm, but clinicians shouldn’t assume an alpha-2 sparing effect at low dose. Instead, we talk practical use cases where trazodone shines today—pre-visit anxiolysis, postoperative stall rest—and where the next wave of research should go, especially recovery scoring and dose-timing strategies that might translate sedation into fewer complications.

Along the way, Emmett shares candid career lessons from residency to journal recognition and makes a compelling case for bridging small animal best practices to equine medicine without copy-pasting expectations. If you manage anxious horses, plan elective procedures, or obsess over safer recoveries, you’ll find concrete takeaways to test in your own barn: when to reach for trazodone, how to think about xylazine titration, and why the recovery phase deserves as much design as induction.

If this conversation helped you rethink your protocol, follow the show, share it with a colleague, and leave a quick review. Your feedback helps more veterinarians and horse owners find evidence-based strategies that keep horses safer.

AJVR article: https://doi.org/10.2460/ajvr.24.07.0185

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SPEAKER_00:

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SPEAKER_02:

Welcome to Veterinary Vertex, the AVMA Journal's podcast, where we delve into behind-the-scenes look with manuscript authors. I'm editor-in-chief Lisa Fordi, joined by associate editor Sarah Wright. And today we're exploring how oral Trazodon results in sedaceum, but it doesn't quite result in a xylozine sparing effect in horses. With our Journal Award winner, Emmett Swanton.

SPEAKER_03:

Yeah, thank you guys for having me. Excited to be here. Talk about all things horses.

SPEAKER_01:

And before we dive in, could you share a little bit about your background and what brought you to this project?

SPEAKER_03:

Yeah. So I am originally actually from Toronto, uh north of Toronto, um, and did my DVM and undergrad and rotating internship at the Ontario Veterinary College in Guelph, Ontario. Um, and then decided that it was time to diversify the portfolio a little bit. Um, and then ended up at the University of Wisconsin-Madison for my anesthesia and analgesiac residency. Um, and then sort of pretty common for specialty colleges, but for the anesthesia college, we have to publish at least one um primary paper. So this was my resident project. Um, there was a few options when I was, you know, starting residency, a few like projects around the go that I could have jumped in on. Um, but this equine one kind of caught my eye. I come with like a large animal background. Um originally growing up in the country, um, originally wanted to be a cow vet, and then as veterinary medicine does, our paths twist, turn, and 360, 180, whatever you want to call it, and um ended up in anesthesia, but was excited to um work with some large animals and do this project.

SPEAKER_02:

Emma, your AG of our article describes how oral low dose TAS might increase xylosine requirements. What was the motivation for this project?

SPEAKER_03:

Yeah, so that's a great question. And I think globally, like if we take a step back and we look at um equine general anesthesia in general, I think if you pull up, so every few years um across the board, there's this big study that comes out, and it's called the Confidential Inquiry into Perioperative Equine Fatalities. And it's kind of where we look across the globe, lots of countries participate and we kind of assess like what's going on in terms of perioperative fatality when in relation to anesthesia with our equine patients. And um, most recently, um, we the new one was just published this spring in 2025 in VAA. And what we found is pretty consistently that the mortality rate of horses undergoing general anesthesia is about 1.2%. So, and then if we break that down further, because obviously colics are a big part of horses going under anesthesia, but if you kind of tease out the colics and we look at just like even healthy horses undergoing elective procedures, um, their mortality rate is still about 0.6%. So it's really, really high when if we look at a comparison in this number to say small animals, um, what you'll find in the new edition in Lum and Jones is they do a really nice job of like kind of summarizing all of the mortality studies in small animal patients that we have out there. And again, there can be so much variety in of like what's included in this, what's included in that. And kind of what they synthesize it down to is that small animal patients, dogs and cats, healthy, undergoing elective general anesthesia, um, that mortality range is about 0.05% to 0.25%. So, like a huge difference in that our equine patients have a lot higher risk of mortality under anesthesia. Um and then we know that the biggest time for our e-coine patients to have a mortality event or to have complications is definitely going to be recovery. Um, because you know, we have these big horses that, you know, they have their fight or flight and they like their knee-jerk reaction is to like fly up and get away from us. Um, and then when they're under inhaling anesthesia, they have like a lot of muscle relaxation and they're usually not steady on their feet, and that predisposes them to myopathies, fractures, all of these like really horrible things that can result in mortality and you know, sometimes them having to be euthanized in recovery. So, what we typically do is that a lot of times our patients have to be heavily sedated, e-coin patients have to be heavily sedated going into recovery. And the idea is that we keep them asleep under injectable, and then they're gonna breathe off that inhale, and then they wake up with from an injectable recovery, they wake up nicer. So the idea with this study was that if we gave them trazodone up front and we got them maybe more sedated preoperatively, maybe they needed less drugs to get to that safe plane to induce them, because obviously um we need a horse to be very sedate to be able to induce them because we use ketamine dazlam. We don't want them to be excited from the ketamine. Um kind of our homework pre-operative sedative and equine patients are alpha twos, which um I could go down a rabbit hole about why we want to reduce the amount of alpha twos we sometimes give our patients, but um, we won't do that. And um, so trying to reduce that up front, and then if the trazodone sticks around and they can recover better, the idea would be that might help them as well. So that was kind of the the reasoning for doing this study was seeing like where can we continue to improve this like population of patients that's at a relatively high risk compared to the other species that were nestizing.

SPEAKER_02:

Is there evidence or clinical observations to suggest this interaction between Traz and xylosine?

SPEAKER_03:

So the one that so um obviously the signing, the findings in our paper were that we had increased sedation scores, but when we look at the low dose um trazodone group, they actually required more xylosine. And there had been nothing previously published about that out there in the literature. I think this was there's very limited studies about trazodone and horses at the time of this when we were doing our research. And a lot of them just more focused on like there was one that like looked at how often they were walking in their stalls, if it was like good for K-dress. There was like a study about using it for opto exams. So this really was like there was nothing out there about the drug interaction. This was kind of the first of its kind and the first of the findings reported.

SPEAKER_02:

So, what are the clinician anesthesiologists surgeon takeaway from this study?

SPEAKER_03:

Yeah, I think that the great takeaways from this would be that we definitely can see an increase in sedations. So I think there is a place for this in our equine patients, and especially postoperatively, if you want to put a patient on cage rest um and stuff like that. I think that we there is a role for trazodone. And I think, you know, one aspect that our our study at this time didn't really look at is the recovery. And I feel like that's a whole untapped area that can be explored. And, you know, um, as a resident, we move on from where we trained. So I have like moved on from the university, but um I know there's like work on clinical studies there looking at like recovery scorings and stuff like that, with um horses getting oral trazodone as like the next steps of like the foundation this first paper laid down for them. So hopefully that will be continued to find good results and use.

SPEAKER_01:

So, what are the key take-home messages you hope veterinarians and clients will remember?

SPEAKER_03:

Yeah, I think like the key, the key takeaways that I hope people remember is that, you know, trazodone and perioperative like oral sedatives um are not just for our small animal patients. I think, you know, clinicians are really good in the small animal world of like, you know, dogs and cats are coming in on their Gab and Tras before their anesthesia, before their visits, and that's great. And we that's great for the patient anxiety, but also from an anesthetic perspective, I can find you lots of papers that show you Trazodone Gabapentin are gonna reduce your propofol, they're gonna reduce your gas. So I think that we need to like shift the mindset and remember that we can also use those on our large animal patients, and it can be beneficial too.

SPEAKER_02:

It's not just the gas to the patient, it's the gas in the environment as well.

SPEAKER_03:

Exactly. Yep.

SPEAKER_02:

Yeah. All right, let's shift and talk about winning one of the AVMA Journal Awards. How did it feel, Emmett, when you found out you were nominated and then you that you won an award?

SPEAKER_03:

Yeah, I was so excited. I remember, I think like I had just started board study, so um kind of a dark day. You know, you're sitting at home for weeks at a time, holed up with textbooks and charts, and then getting this email was like so, so exciting. I remember like the first people I texted was like my two faculty who were on the paper with me, Carrie Schroeder and Becky Johnson. I was like, oh my God, look at this. This is so exciting. So um, yeah, we all three of us were super excited.

SPEAKER_02:

Well, you already answered my next question, which are the primary people that, you know, the immediate ones you want to reach out to. Uh, and for other listeners, if you could go back and tell your resident self or your students one thing about this journey into residency, completing a project, uh, getting it done, designing the project, what would it be?

SPEAKER_03:

Yeah, for sure. I think, at least for me before like I went into it, I had this like guised or this idea that like research was like, you know, scientists sitting at their lab benches or sitting in labs in white coats, um, and that like it wasn't fun. Um, and that some of those results like weren't necessarily applicable or like had like clinical relevance. Um, so I think like what this study showed me that you know, research can be fun. Like I said, like uh myself and the two other faculty, you know, we spent days at the barn with the teaching horses. We were having a grand old time, um, you know, hanging out. So it was lots of fun. You know, the sedation score we used, like it's a validated equine sedation score, and it involves like opening an umbrella in front of the horses. So like we're out there in the middle of Wisconsin in the winter, like opening umbrellas in front of horses. So I mean, it was fun. And then I think like the results are really cool and they're like applicable and useful. So I feel like I've talked to like equine colleagues that are like, hey, like we saw your paper and we like give our patients trazodone and it's like they're sedated, they send their stalls. So I think that's been like super rewarding and just like a shift in mindset that I think um research can be fun and it can find results that are actually gonna hopefully improve things for our patients.

SPEAKER_01:

So I'm so glad you said that actually. I have a friend who is a small animal general practitioner from vet school, and I was getting dinner with her this weekend, and she was like, Sarah, I don't know how you do your job. She's like, I could never do that. I'm like, no, it's not just like bench top research, and like it's really cool advancements and like getting to see that and being at the forefront of the field and advancing it. Like that's how we learn what we learn in vet school, even it's like what's in the literature and what works. So yeah, thank you for sharing that with our listeners.

SPEAKER_03:

Yeah, super cool.

SPEAKER_01:

So, how has receiving this award influenced your the research or your career since then?

SPEAKER_03:

Yeah, I think um I think like um, like I said, like I've left the university. So not necessarily like in the huge research um field right now, but I think it's definitely like opened my eyes that if there is a time in my career, because the beautiful thing about veterinary medicine is lots of different avenues for us to go down. Um, that like I wouldn't be afraid or like be abrasive to like going into a position or another career path that involves research. Like I would love, you know, I think like large animal patients, like they definitely aren't don't get as much attention as for the anesthesia for research in general, but especially anesthesia, that I would not hesitate at all to like, you know, go work somewhere and like you know, be a large an equine anesthesia researcher or even, you know, a bovine um equine, or I guess not equine, but a bovine anesthesia researcher. That's uh my Wisconsin coming out. But uh yeah, I think it's definitely like made me less hesitant to like, you know, if I see a job post and that requires research to like, I'm not running away anymore, kind of thing.

SPEAKER_01:

And what advice would you give to other researchers that are hoping to make that kind of impact in their own work?

SPEAKER_03:

Yeah, I think like it's really important to find a project that you're like passionate about and that does have clinical relevance. Like, you know, I love large animals and I love anesthesia. So the idea that I can maybe improve ecoine anesthesia, even if just a minuscule or even just building a foundation for like further clinical studies that other people can go on and like take kind of that torch to the next step, um, is really exciting. Um, and I when you're passionate about it, it's like not hard. Like I was like, oh, I can write and talk to anybody about e horse anesthesia, like sign me up. Um, so I think like that's definitely really important.

SPEAKER_02:

Yeah, but in in your uh career to date, were there any pivotal moments or challenges uh that really shaped your path?

SPEAKER_03:

Yeah, I think like if I obviously, you know, being a someone in a specialty, I think there's always like that pivotal moment that we like think about like the day we actually like were locked in that I was like, this is what I want to do. And for me, like it's actually related to being a vet student. Um so like I'd said I was a student at OVC and uh originally like thought that I wanted to be cow vet, and then I like spent uh a win some time in a winter in Ontario with a large animal vet, and I was like, oh my god. I was like, one arm is warm, but that's not for me. Like I can't do that. Um then I yeah, so then I um was like, oh, maybe I'll do critical care, like we'll do something exciting. And um there was a criticalist that had like taught taught us in our DVM program um since kind of like day one. And I just remember like I thought she was so cooler. Um, Dr. Bersanis, Lexa Bersanus, and she was like just like made everything fun. And so I'd reached out to her and I was like, hey, like I think I want to do um ICU, like any summer job opportunities research, like what would what would you recommend I do? And um at OVC they hired two summer students to work in the anesthesia department, and she was like, I would go work in the anesthesia department, you're gonna get a see a bunch, do all these like clinical cases. Um so then she sent me to the anesthesia department and I never looked back. Um, I do remind her that when she's always like, Yeah, you ditched me for critical care. And I'm like, uh nope, you're the one who sent me to anesthesia, so it's your own fault. But yeah, I think that was like a pretty pivotal moment where I was like, you know, if I don't think she'd pushed me to anesthesia, I don't know if I would have found it. Um, but happy I did. Love, love what I do.

SPEAKER_02:

It's such a great career in veterinary medicine. There's so many options.

SPEAKER_03:

Yeah.

SPEAKER_02:

What going back a little bit further? What first sparked your interest in veterinary medicine and ultimately led to where you are today?

SPEAKER_03:

Yeah, I think um, so I growing up like north of Toronto was kind of rural Ontario. I was like in immersed and um very much like agriculture. That's actually what my undergrad is in. I showed beef cows growing up, I worked on dairy farms. So like I was like locked in, gonna, you know, be a part of this agri-food system, um, which I think all those veterinarians are very smart and very thankful that they're there. Um, so that's like kind of what had started me on this journey is I was like, oh, I see a role, I see a need for like rural veterinarians. Um, and that's like what my plan is gonna be. But um, the twists and turns had other, other things in store, but it definitely was like those early experiences of like working with cattle and stuff like that that was like influenced me to go into this this career.

SPEAKER_01:

So, Emmett, what is one piece of information the veterinarians should know about using oral trazodone in healthy adult horses?

SPEAKER_03:

Yeah, I think like the one simple piece of information they should remember is that oral trazodone in horses works and that we should be using it and incorporating it um in for our equine patients.

SPEAKER_01:

And for clients, what's one thing you wish more horse owners understood about this topic?

SPEAKER_03:

Yeah, I think that I wish more horses um owners understood that there are like other options in terms of just our conventional, you know, xylazine, academy medazle and xylosine and recovery, and that there are lots of things that we can do. Um, and lots of and other options other than domator gel for your anxious horses that you stay in a stall. Um, that we have other things in our toolbox and don't be afraid to ask your veterinarians for them or um you know open that conversation for sure.

SPEAKER_02:

All right, Emmett, before we wrap up, we're gonna have a little fun. First, I need to know do you have a pet?

SPEAKER_03:

Um, so I did uh um the very classic thing of I got a German throat hair pointer during COVID that I love dearly. Um, but I don't think she was she wasn't made for residency life. She was made for living out in the country at my parents' house. So I have a dog that I I pay all the bills for, but um, she resides in rural Ontario quite contently.

SPEAKER_02:

If she could describe you in three words, what would she say?

SPEAKER_03:

Yeah, I think that she would honestly think I'm pretty annoying. I love to bug her. Um that I also was this I'm the snack police in the household, and that's probably the veterinarian in me that I'm like, yeah, you don't need anymore. Um, and also the bed hogger, even though I would argue she's the bed hogger, I'm I'm sure in her mind that when I'm at home and we're sharing a bed, she really wishes I would leave.

SPEAKER_02:

Are you a coffee before rounds person or a coffee all day person, or are you a coffee person?

SPEAKER_03:

I am a black coffee all day, every day person.

SPEAKER_02:

No cutoff point?

SPEAKER_03:

Nope.

SPEAKER_02:

Any special brand you like, best of all?

SPEAKER_03:

Um honestly, as long as it's hot and it's black and it's full of caffeine, I am there.

SPEAKER_02:

All right. Do you carry a thermos around so you can have it hot all day, or where do you get your coffee all day?

SPEAKER_03:

Um, so we used to have what we call the jailhouse coffee machine at Wisconsin. That was like this free coffee machine that had horribly tasting coffee, but it was there all day and it was free. So that was a pretty common place. Um, but yeah, otherwise, you know, I have drag around a yeti that keeps it pretty warm most of the day.

SPEAKER_02:

Of course. Um, you know, we talk a lot about wellness and work-life balance in veterinary medicine. So, what's your go-to stress relief after a long day and even over the weekend?

SPEAKER_03:

Yeah, my um, well, I'm a big like get up and go to the gym before work person. So I am one of those like scary people that's getting up at 4 a.m., going to the gym before I even get to the hospital. And that was like alter residency, something I've carried into now private practice life. Things just very important to move our bodies. Um, but if like my guilty pleasure is um ved being uh vegetating on the couch, um watching reality TV, especially um like real housewives of Salt Lake City. That's where you're gonna catch me nine times out of ten. That's awesome.

SPEAKER_01:

I love that. Ahmed, do you watch baseball?

SPEAKER_03:

I was like a bandwagoner because I know the blue jays. Yeah. Um, as a Canadian, I have to, you know, support the Blue Jays.

SPEAKER_01:

So that's all I'm asking.

SPEAKER_03:

Yeah. For about like the last week, I've understood what's happening with the Blue Jays, but that's about it.

SPEAKER_01:

Yeah, I was gonna say sorry for your loss. You watched the game on Saturday. We were we were winning for the Blue Jays as well. The daughters got their time. Well, Emmett, thank you so much for joining us. You really appreciate you being here with us today.

SPEAKER_03:

Yeah, thank you guys for having me. This has been great.

SPEAKER_01:

And for our listeners, you can read Emmett's award-winning article in AJVR. I'm Sarah Wright here at Lisa Fortier. Be sure to tune in next week for another episode of Veterinary Vertex. And don't forget to leave us a rating and review on Apple Podcasts or wherever you listen.

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Lisa Fortier, DVM, PhD, DACVS

Co-host
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Sarah Wright, DVM

Co-host