Unlocking the Secrets of Sarcopenia in Senior Horses

Music. Welcome to Conversations in Equine Science. Kate and I are back for an episode today.

And I just wanted to remind everyone, before you would implement any of the changes that the research paper might recommend, be sure you check with your equine veterinary practitioner or your farrier, trainer. Just double-check with your equine professionals before you implement any of these changes. So today's paper is titled Retirement Risk Factors, Exercise Management, and Muscle Mass in U.S. Senior Horses. The paper is by Elisa Herbst, and it was published in May of 2023.

That what is so cool about this paper it is information on the management and health of u.s senior horses so they put an online survey out there and the intent of the survey was to uncover the primary use of these senior horses now senior horses are horses over the age or equal to the age of 15 years of age. So they did have a requirement that the owners who responded to the survey had to at least own the horse for one year.

So they uncovered primary use, reasons and risk factors for horse retirement if they were retired, exercise management. Low muscle mass, or sarcopenia, and they uncovered the risk factors for the low muscle mass and how the owners perceive the consequences of that. So they did get 2,717 respondents, and they put all the data and information through, logistic regression and ANOVA, and then they ended their analysis with the Kruskal-Wallis test, and that's a non-parametric test.

Test and it's used to determine three or more independent groups and whether there are significant differences between the, I would call it the sum of the mean ranks. So when they are comparing these three or more groups, they will rank them and then they'll compare the sum of the ranks and then they'll be able to say if it's statistically significant or not.

So Kate, did you get to read this whole paper and some of the dynamics that occur with our senior horses? Yeah, I think, I mean, I'm more leaning towards some of the data that really interested me in relation to my own senior horse. So there was parts of this that I just found really pertinent. But the very first line I thought was just a great standout that senior horses represent up to one third of the global equine population.

And I just thought that's a great moment to pause and to realize where we've come or how far we've come with our management. And I know this paper does highlight that we really need to address the basic management and preventative health care because essentially health problems, other studies have suggested as well, that health problems can be under-recognized by owners. But for them to still represent one-third of the global equine population.

We're seeing that obviously horses are going into their senior years and are thriving, hopefully, still up until those later years. And we just need a little bit more research like this that's being carried out to see how we can improve our management in those later years so they continue to thrive as much as they possibly can. Because some of the other parts that kind of stood out to me is things like the people who responded. to the survey.

So 35% of them were equine professionals and how they equated that was that they earned more than 50% of their income in the horse industry at some point. And then the other 65.2% were hobby horse owners based on how they define that in the paper.

But in terms of the information you're getting back like that's really insightful information because to have such a high percentage of people that have a really um i suppose specific or in-depth knowledge we would hope of having worked in the industry it just to me i was like i feel like this is really getting across quite. I don't know how to word it, but quite an important aspect of the care that we're getting through to owners that are really entrenched in the equine industry.

And this is more than just a passion for them. This is something that they've spent a portion of their lives doing. So they have a real buy-in to understanding the horse at a higher level.

And that's not to criticize hobby horse owners because I am one of them and I've always just has my pony but I think it does bring that degree of just possibly a little bit more information and maybe that differentiation of how we can pick up on these signs quicker but as we kind of go through some more of the research I've had some ideas and maybe ideas for papers we could do in future to announce to just try and bring awareness, I think, to how we can pick up on our horse's aging signs.

Yeah, and I always think, you know, you can be in horse racing, but you're only seeing young horses that are fit and in the best of shape. So now that I have some senior thoroughbreds that I had on the track, it's a whole new ballgame. And what's neat about this paper is they compare it to humans aging.

And we know that in humans, as you get older, physical activity and fitness, that provides huge amounts of benefits. And so one of those benefits is age-related loss of muscle mass. Strength, and functioning, you know, balance, everything you tend to kind of lose if you don't use. So I really was attracted to this. Greta is 28 now. I did notice some muscle mass loss along her top line. And so my veterinarian, you know, did agree that I could give her some more amino acid type of diet.

So alfalfa pellet soaked, easier for them to chew. She likes it. It has really added some muscle mass to her. But then I also give her a supplement. And back when she was younger, she didn't need this. She was pretty much an easy keeper and at times could be a little bit overweight on the grass. Well, now the grass just doesn't cut it. It doesn't give her everything she needs. And it's probably because she doesn't absorb her nutrition like she used to.

So, and also I kind of thought, oh, she's lost that top line. I'm going to be easy on her, not have her in such routine exercise. And that may have been a mistake because it's through even the ground pull exercises. And I think in this paper, they call them dynamic mobilization exercises. You know, I need to keep that up with her. And 38% or almost 39% of these senior horses in this study did pleasure riding or driving.

But they did not do it to the extent of the horses that are still seniors and still in competition. So I think almost 40% were fully retired. And, you know, I think sometimes even with ourselves, we let age limit what we do. And you can't do that. You got to keep going forward. And, you know, I think if anything, I have never worked out so much as I have now, because when you're younger, you can maintain physical fitness. You take your progrances.

Yes, you do. And then all of a sudden, you know, you want to keep muscle on. It helps you even with bone density exercise and that, you know, weight bearing is a lot. Well, it's the same in our horses. So I was attracted to this mainly because it kind of talks about the vicious circle of saying, oh, she doesn't have much of a top line.

You don't really want to put a saddle on a horse that has a bony area along the backbone, but you can certainly do those dynamic mobilization exercises and you don't have to get on them. And so anyway, we did an episode on dynamic mobilization exercises. And Kate, if I remember right, I did it with Greta and we did see an improvement with her back muscles. And I think it was 10 minutes on each side. So you were stepping over jumps.

Me being on the ground, leading her, stepping over jumps, going to the right, doing circles, going to the left. And it was like five different exercises that took 10 minutes each direction. And after, I believe I had to do it for a month, we saw improvement.

So we can't forget that, that just because they're retired, you just don't put them in a pasture. Because I think one of the things that bothered me, and Kate, chime in if this bothered you in the paper, that it affected their ability to get up and down. So they're out of a pasture and they can't get up. How many times do I see that in Facebook groups where a horse is down and they need the emergency crew to come to hoist them back up?

Well, that may be when that horse's quality of life has to be questioned. And they say the same things in people, though. Your ability to sit down on the floor and get up again is a predictor of longevity.

And I think just from two things that you touched on there, Nancy, I remember the pole work episodes and thinking and possibly saying in the episode at the time that it's such a, I suppose, like a simple exercise that's so overlooked and something that I think you kind of get into your head that it's almost like baby steps or baby work.

I know sometimes when we're going out and riding and we want to do the exciting stuff and it's like the interesting things, but doing that groundwork exercise and getting them to actually lift their feet. And like you said, Nancy, hand walking them beside them. Like these are the things that are going to maintain the muscle into later years. And there's probably an element too that when you start to see that top line.

Lessen or it's starting to waste that little bit there for me i think it's the are they going to now overdo themselves and exercise are they going to end up hurting themselves or injuring themselves and you can almost want to wrap them in cotton wool a little bit and think like okay well we won't do this and we won't do that but you know if they were able to keep up with it before it's just about being very mindful and checking in with them and you know just making sure that they

are still able to maintain that work but to balance this with bringing in more of this and groundwork that really does strengthen them because it just it sounds so simple but the lifting of their feet like in the coordination that does a lot even from a mentality point of view. And that's really important as they age. But I think the other aspect as well is sometimes when we start to see older horses lose condition, we think feeding them is the solution.

And to a degree it is like we need to supplement. Certainly, we need to make sure we're balancing their ration correctly. And that has changed with age. You know, there comes a point where you can't keep feeding them the same way. You have to change for their lifestyle. But if you're not getting them to do the groundwork and you are giving them the calories, then all you're doing is adding fat to an older horse. And that's not helpful because fat is going to have an inflammatory response.

So if they do start to get arthritis, that's going to inflame it.

It's going to put more pressure on the joints. so really like it's about taking kind of a shift in how you were working or exercising your horse and trying to maintain it which you know take a little bit to get into a new routine of doing hand walking and ground exercises and not riding as much anymore but like you said Nancy you saw that difference in her that time when you were doing it so you know that might make a big difference in bringing her top line back just now yeah and

sorry the last point was actually when you mentioned about them the getting up and down that's I mean it always comes back a lot of these things always come back to me about how important sleep is in horses and if they can't easily get up and get down they're going to reduce the amount of times they have to do that And they can't enter REM if they're not lying down. And REM is where our bodies heal and clear our brains of toxins.

And it's such an important aspect. And even though horses can sleep standing. They can't enter REM in a standing in that stay position. So. I think you start to see a huge decline in them when they start to get stiffer to that point. And I'm sure that definitely plays a big role. They said that 30.5% of the owners reported that their horses had problems getting up.

And that's how they recognized the sarcopenia. But I was like, oh, that breaks my heart. because as prey animals, they will struggle and they will keep trying to get up. And that's sad for an older horse to go through that. I would much rather maintain the muscle mass as much as you possibly can so they don't have to go through that portion of it. And then they said that one in six senior U.S.

Horses have been affected by sarcopenia. So it's a part of the aging process, but just like elderly people, it doesn't have to be, you know, and I will say PPID makes a difference in this because people, is sometimes PPID, the horse is underweight because it's not able to absorb its nutrients or get rid of its hair coat. There's a lot of metabolic issues with it. You add more food to the diet, it's going to go into that crusty neck.

And when you see that those fat patches on a skinny horse, you're not feeding correctly. And, you know, luckily my vet and I both agreed amino acid supplementation was the way to go.

And it has made a big difference. It's so rewarding when you walk into the barn in the morning and she's got that alert look in her eyes like she did when she was 10 years old yeah but you know through the winter last winter there were times and we had a rough icy cold winter and I questioned whether she was having quality of life she was walking on the ice fine she was dealing with the cold with a blanket but she just kind of had a

dullness about her and I did too when we had a month of ice on the ground. But anyway just adding that and you know it was so helpful because I rely so much on my veterinarian because he knows my horse experience but sometimes you always want to have that second pair of eyes on the horse even if you are an equine professional because you see them every day and you might miss something so i'm kind of like always that second pair of professional eyes are good to call in,

Yeah. And I think it is that thing of if you're looking every day, very subtle changes can become normal to you, like your conditions to see in them. So it really does take someone else coming in like your vet who hasn't seen the horse in a couple of months and is like, oh, she's really changed. And then you're like, oh, like it doesn't click, you know.

But I think actually in terms of speaking to the part of this research that was about mayors and just because they have a special place in my heart and I found it really interesting actually that well first of all they're more likely than geldings to retire early and they thought a part of that might be around them having breeding careers or entering into breeding careers and not engaging in structured exercise during that time.

But what I found really interesting about the information or the data they gathered in this is that the ability to thermoregulate during exercise, the maximal aerobic capacity and the maximal heart rate appears to be diminished in older mares. So this suggests that higher intensity exercise protocols that are used in younger or middle-aged horses will be inappropriate or may be inappropriate for older horses. And this does kind of speak more to higher level competition.

But it said it is also relevant for horses of other uses that are still doing kind of high workloads. And that basically will have to reconsider how they are exercised. But that thermoregulation.

During exercise in this point but in general like as they get older that thermoregulation diminishes and that's how you were saying Nancy you know you were rugging Greta up and even was it this winter just passed you had her rugged in the stable yes it was one of the first winters I did not I did have a blanket on her inside the barn I just always take the blankets off when they come in and the pony doesn't even need a blanket. She's got enough fat insulation to last her a lifetime.

And, you know, for the older ones, I would blanket them because of the wind and the precipitation. And, you know, they need to go out and move because most more than likely since they're ex-race horses, they have arthritis.

And, but when I bring them in, I take the heavy blanket off and I might put a thinner type of covering on them like a cooler type and so anyway this winter there were a few weeks that I kept the heavy blanket on now I took it off groomed her and then it you know for her night hay I would put it back on so and this is the I think, Kate. This paper talked about how when people retire their horses, they give them less management and less health care.

But in retrospect, it has increased my management and my health care because they require more oversight and like me taking on and off the blanket. And mainly when they are older, they get such a large hair coat. When you blanket that hair coat, If you don't let that breathe a little bit, take that blanket off and curry them, they get this like scurvy stuff along their skin.

And I didn't want that. And sometimes that's an immune deficiency, but I would curry her and fluff that fur, let her air a little bit through the evening. And then before I went to bed, I go out, throw hay. I would put that blanket back on again then. And I just didn't want her burning calories trying to get warm. So it increased my management and healthcare. And I thought, darn, you know, when they're two years old, it's a piece of cake.

But this takes a lot of thought and a lot of deep thinking on what that horse needs at particular changes of seasons so then spring comes they've got this big hair coat and then the clippers come out because you don't want them sweating and you know then it gets cool at night so it's just you're still blanketing them yeah you know that's that's it it is more management and it is more time and you know.

What it's a really lovely thing that we get the privilege to do that that we've had a force come into these years you know and because of our care and taking the time to actually support them means now in their later years you know like that we need to do blanketing or we need to do the exercises or even do some stretching with them as well and it is definitely a consideration that means you're going to have to build a bit of a routine around it but I think when

you get to that point too it's such a beautiful opportunity I suppose for your connection that you've had with this horse for so many years and now you're doing even more kind of of the bonding techniques like the grooming which is so important to them and hand walking exercises like you're now down beside them and really I don't know spending I feel like really connected time with them so even though initially it might feel like you have to.

Allocate more time to it. I know as people in this day and age, we feel time poor all the time, but it's a brilliant opportunity to just kind of reconnect. And, you know, I do treasure the time I spend with her because I've never had a horse this old before. And I had her as a yearling on the racetrack. So I think she came to the racing barn when she was a weanling. So I've known her probably longer than I've known most people.

So, you know, I treasure the time. I also, you know, have her on a arthritic type medication, and then she gets glucosamine injections as well to just try and keep her as comfortable as possible. The one thing I wanted to say is that something else I do is I really maintain her hoof health, you know, frequently. So if I begin to see a deviation or a flare occurring, I don't wait for that four to six week grow out.

I take care of it right away because their joints and their tendons are more likely to be injured as they age. So that's a difference too right there. But boy, do they teach you a lot. Yeah, and I think that had come up as well, possibly in the research. I remember reading something about them being that that was another reason for retirements. I can't pick it out just now, of course, when I go to make a point about it in regards to their lameness.

But yeah, just another point that I was going to make on this paper that I thought was really important is they were talking about that owners could be learning to muscle score more effectively, essentially. And muscle scoring is one of the things that you have to practice and to become efficient at it. And then there is still a level of subjectivity because your interpretation can be different to a vet's interpretation, surely.

But the more that you make yourself familiar with this, the better it is for your horse. And there is a scale that you're able to use or a scoring system. So there's the equine muscle atrophy and scoring system and it's called m-a-s-s so they were saying that owners could be trained to use something like this and it would make a difference yeah and if you just go to google scholar and put in herps because alisa did the same research on the mass scoring system.

And I believe that came out, let me look here, in 2022. So if you read the paper we're referencing today, I'm sure she listed it as a reference. But anyway, yeah, that would be a great thing to recognize when they are losing muscle and kind of get ahead of it before it gets too far out of reach to bring back. And it says, like you had mentioned, Nancy, you know, that you...

Do actually utilize your vet like they said that using the muscle mass score you can then understand when there is atrophy and that that is your indication like that is your red flag to contact your vet because the vet is going to identify the source of the atrophy and instead of just being like oh well they're losing muscle because they're getting older it mightn't be you know just down to that it could be actually like you said nancy something with the hooves or there could

be something else that's throwing them off and that's why they've muscle wastage and so the vet can then come up with a treatment plan to reduce the risk of further muscle atrophy and then also you know talking about making adjustments for the stage of life they're at yep yep i think that's a good point to end on, Kate. And I'm so happy we were able to reconnect and get together again.

And we're just like inundated with this PhD research. Maybe we're the ones that need our head examined for doing this. It feels like that most days. Like it is, it is definitely a hard slog. But you know what? It's good to reconnect and just focus on a research paper and talk about it. And so we'll try and maybe do this as frequently as we can in the future.

And so happy the listeners have kept with us and are keep sending in emails and to see what we're doing and are we coming back and things like that. So we are, we just might not be as frequent as we used to be. Yeah, but then once we both get the other side of this PhD, we'll be back to business as usual.

Yeah, then we'll really have some conversations, right? Yeah, well, if we have words left. We probably won't, so. Okay, well, thanks so much, Kate. I appreciate the time you took to do this, and we'll see you, Nancy. We'll see everybody in the next episode. Music.