Back to Stories & News

November 17, 2020 – Dr. Kelly Diehl talks with Dr. Patricia Harris, a European Specialist in Veterinary and Comparative Nutrition. They discuss the equine obesity epidemic and how to determine a horse’s body condition. Dr. Harris also offers advice for owners on how to help their horse lose weight, as well as strategies to prevent obesity.

00:09 Dr. Kelly Diehl: Welcome to Fresh Scoop, Episode 26, Nutrition and Obesity in Horses. I'm your host, Dr. Kelly Diehl, Morris Animal Foundation, Senior Director of Science and Communication. And today we'll be talking with Dr. Pat Harris. Dr. Harris is the Director of Science for Mars Horse Care and Head of the Equine Studies Group at the Waltham Petcare Science Institute. Pat, thanks so much for joining us today.

00:34 Dr. Pat Harris: Thanks. And firstly, many thanks to the Morris Animal Foundation for this opportunity to discuss a very important issue, and for their support for equine research in general. Thank you.

00:49 DD: Yes, and thanks again, a big thanks to Pat, because as you guys may tell, we are speaking across the pond, as it were. So Pat, before we get started, I always ask people kind of how you became a veterinarian, what drew you to veterinary medicine, and then your specialty in equine nutrition?

01:11 DH: Yeah, well thanks. As to my background, in fact, my parents had no history of having horses or any animals in fact, but I have to say they were amazingly supportive of the passion I developed for horses. And when I was very young, what happened is, we moved close to a small riding school in the countryside, and they very kindly allowed a very small horse-mad child to spend most of her time trying to help, and it was trying to help, because I was tiny and they helped me to learn to ride. And this really started my lifelong association with horses, which led me eventually to train to be a veterinarian.

01:49 DH: And then as you said, during my PhD into tying up, I actually found my passion for nutrition. And I always say I trained to be a vet, but I chose to be a nutritionist. And that is because I realized it plays such an essential role in the behavior, welfare, performance, and perhaps most importantly, the health of horses. And so that logically lead me to joining Mars and the Waltham Petcare Science Institute in 1995, seems a long time ago now, where I genuinely have the privilege to manage the Equine Science Program for Mars and Mars Horse Care. And as you say, I work in collaboration with experts at institutes and in universities all around the world. And this really enables me to help ensure that the scientific insights that we find can be used to help in our aim to make a better world for horses. So that's my background.

02:46 DD: That's awesome. And diving into our subject today, I... Everyone listening knows that there's an obesity problem, obviously in people, and I think we know, and there's more information about obesity as a problem in dogs and cats, but I think a lot of us who don't know horses, and maybe even people who do have horses don't think about them being overweight, and so can you tell us a little bit about the magnitude of this problem in horses?

03:16 DH: Yes. To give you an idea, obesity is actually seen as one of the most important welfare issues in the UK, the USA and many other countries. It can be present up to 30% of the equine population, in particular in those horses and ponies used for leisure purposes. However, it still can be found in certain competition horses. So for example, a study we did in the UK of over 330 horses and ponies that were competing at a national unaffiliated championship, we found that 41% were overweight and 21% were obese and that show and dressage horses were the most likely to be overweight in that study. But even more than that in some breeds and types, it may be even higher.

04:06 DH: So for example, again, in a recent study we did of nearly 450 ponies in the UK, with the Royal Veterinary College, 70% were obese and less than 1% were underweight. And the same occurs when we look at the surveys in the USA, depending on the breed and type, it also suggests that between 30% to 40% of the animals evaluated were overweight or obese. And I think part of this is it seems today that many owners have a poor ability to visually identify an overweight animal. And part of the worry is that because equine obesity's becoming so common, in fact, for many of us, we now accept it almost as the norm.

04:51 DD: And I think that's a problem in, I know in dogs and cats as well, but I didn't realize it was hard for owners looking at their horse to see obesity. Are there guidelines? There are in dogs and cats. There's the Purina Score System, for example, looking at body condition. So are there similar things for horses?

05:13 DH: Yes, we can discuss about how you can assess obesity, if you'd like me to, because that's how we use... We have body condition scoring systems, so if... You're right, it is difficult. And a lot of people look at an animal and they might just assess it, or they use a weigh tape, but it's not really an accurate record of the horse's condition. And more importantly, it doesn't pick up where the fat is accumulating in that animal, and some of them may have regional, and some of them may be globally around the horse. They have fat accumulating. So you're absolutely right. Our recommendation is that all of us ideally should learn how to actually body condition score correctly, and this involves you feeling and palpating the horse, as well as looking at their general appearance.

06:03 DH: You're also right, there are several systems around, and in general, providing you become experienced and consistently apply the same method, then using any system can be beneficial. I personally use one that was developed by Henneke in the USA and is being adapted by Kohnke, and it basically uses a nine-point scale. And it's, again, this combination of a visual observation and palpation. And you look at six areas of the body, you look at the neck, behind the shoulder, withers, ribs, the loin and back, and then the tail head, and you then assign a number to each of those and the amount of fat that's accumulated in there, you then add those up and you divide them by six to give you an overall score. And so the final score range from one to nine. So one is defined as very poor and nine as extremely fat, and then both being severely underweight, which is a body condition score of three or under in this system, or being obese, which we define as seven and above, they are associated with those higher risks of health problems.

07:17 DH: So if we get a general guide, we're wanting to think for a general leisure horse, somewhere around a body condition score of five, perhaps a little bit toward six towards the end of the summer, especially as they lose weight in the winter, and then we're asking them to be around five, perhaps a bit towards four and a half towards the end of the winter. And actually a bit like the systems in dogs and cats, when you use this as experienced people, it can be very reliable and consistent, and actually it correlates very well with the total body fat content. Because they're animals in a stable body condition, the amount of fat you can feel on the outside is equivalent to the amount on the inside. So it's a good guide, but only if they're in a stable body condition score. But there is one caveat, just if I can add, they're very difficult to do. They're actually really difficult.

08:17 DH: If you're only doing it occasionally and you're not experienced, body condition scores can be difficult for people to do. And so actually, we're just about to submit for publication from a multi-centered project, and which is led and coordinated by the University of Melbourne, a body condition index score. And this actually uses measurements that you can measure on your horse or pony, and then you can put those into an equation, and it gives you an indicator of their body condition score and their percentage fat.

08:53 DD: That sounds more really useful for folks. And so you mentioned this, and I think people know for humans, obesity is associated with, for example, Type 2 Diabetes, we know of the obesity impacts in dogs and cats. Can you talk about some of the diseases that are really impacted or... I don't know if I want to say caused by obesity in horses, but that maybe you see an association between?

09:22 DH: Yeah, I think it's really important. And as I mentioned right at the start, obesity is becoming this globally recognized welfare issue in horses, and it is mainly because it's associated with an increased risk of laminitis, hyperlipemia, and some specific causes of colic, forms of colic. But the list, as you quite rightly say, of these potential negative consequences of obesity, similar to humans and other animals, is quite long, and it actually ranges from the actual direct effects of being overweight. For example, you're just putting added stress on the skeletal system, and then of course, you've actually got to carry around extra weight, which can limit your athletic performance. And then if you think about it, your horse will have just the physical effects of just having more fat, which means we're actually asking these horses to live and exercise while they're effectively being covered in several very high TOG-rated thermal blankets, not ideal.

10:26 DH: And then another thing that I think we're all realizing more and more is that fat is not inert. It's actually very metabolically active and being obese can, for example, compromise fertility. And I think something that we're recognizing in the human population in this current pandemic is that being obese can actually decrease even further the ability of older horses to produce an immune response to various infections, so very, very important. But perhaps the most important, as I mentioned right at the beginning, is the impact on laminitis risk, and certainly obese animals are at more risk of suffering from laminitis. And so the animals that are gaining weight also have an increased risk and obese animals perhaps have a poor recovery if they suffer from laminitis. And that, as you correctly said, is linked with the fact that obesity is often associated with having insulin dysregulation, which we take as having either high basal insulins or an abnormally high insulin response to feeding sugars and starch. Do you want me just to briefly outline what laminitis is for listeners?

11:45 DD: Sure. I think we have a fair number of horse folks, but there are probably a lot of folks who don't know or they're like me, and it's been eons since I learned anything about laminitis. So yeah, please do.

11:58 DH: Well, very briefly, as you say, many of you listening will be aware that laminitis is a systemic condition that manifests in the foot and it results in varying levels of pain, lameness, and basically in some cases, animals have to be put to sleep because of welfare grounds, because it's so painful, and you can't manage it. And I think the most straightforward definition of laminitis is just you fail in that connection between the inner hoof wall and the underlying bone. And the closest I think I can describe it to people is that if you think of having... And it's not exactly like this, but if you think of having a blood blister under four of your fingernails, and then we ask you to put all your weight onto those four fingers, you could imagine how painful it is.

12:54 DD: Right, and for folks who are listening, who may be like my mom, just to give a perspective, even though it wasn't obesity that caused laminitis in this particular individual, but a lot of people listening in the United States will remember the case of Barbaro, who was a great race horse, broke a leg during a race, and was treated, and the leg healed successfully. But people may recall that he was eventually euthanized because he developed laminitis, secondary to the weight shifts required for him. And so I think that term may be familiar to people. Now, what Dr. Harris described, of course, is a different cause, but a more common cause is my impression of laminitis, which is when we have metabolic derangement, so pain and a serious condition, because these are big, heavy animals, standing on toes and pain. So thanks for explaining that, Pat.

13:54 DD: And one thing I should have asked you way back at the beginning in regards to obesity is, are there a sense amongst equine nutritionists and equine clinicians about why horses are having an obesity epidemic too? Is there something akin to what we see in people or what's going on?

14:15 DH: Yeah, it's a very good question and I think we're all aware that obesity basically occurs when your energy intake exceeds your energy output. And I think there have always been obese animals, but I think you're right, a combination of factors have probably increased the proportion that are obese now. And that's firstly, perhaps, that more horses and ponies are maintained for leisure purposes and therefore their energy expenditure is typically lower than when they were working hard. And I think for many of us, we tend to overestimate how much we and our animals are actually exercising, so then we think they're doing more work than they actually are and we feed them to what we think they're doing rather than what they actually are.

15:00 DH: Secondly, I think increasingly, we tend to put rugs on our horses and ponies in the winter or we bring them inside, which reduces their energy losses over the winter. And if you think about naturally, winter is a time when food resources are reduced and in the wild, horses and ponies would tend to lose weight then. And so evolutionary, those animals that what we would now call easy keepers and all those that have built-up reserves before the winter were those that were perhaps an advantage in the past. But now, we have better forage qualities, we have improved feed provision in the winter, plus, we often use rugs for warmth. And all of those, if you think about it, actually ends up that we're ending up all year round with a positive energy balance. And then, probably another aspect is that as farms, certainly in the UK, have diversified, horses and ponies are perhaps kept more and more often on improved pastures. And these are ones that were established for dairy or beef production, and these pastures are very energy-rich and they're perhaps very different from the type of grass your native animal evolved to cope on.

16:21 DH: And then for me, one of the areas that I think recently we've really started to understand is that perhaps many of the older nutrition books were based on work when they discussed appetite and intake. It was based on horses, so typically, horses, we'd say, they ate about 2%, 2.5% of body weight in their dry matter a day. But of course, as I often say to people, ponies never read those textbooks and they don't do the same. So ponies can actually take an intake up to 5% of their body weight per day in dry matter, and they can eat up to 1% in just three hours of being turned out. So when you think you're restricting them, they can eat an awful lot. So again, as a simple example, it does mean that if you turn out, say a 250-kilo pony out onto these very rich pastures, effectively, they could eat enough energy in a day to fuel a racehorse in full race work. So it's not surprising that that race horse is twice their size and exercising a lot more, it really is not that surprising that we have more obesity. So many reasons, and they will be different in each case.

17:40 DD: Right. Well, that was really interesting. I never thought about them being able to eat that quickly. And that ties in with something I wanted to ask you to help with our audience who is listening, and I know this is a heavy lift, but can you describe as briefly as you can, some of the differences between a horse's gastrointestinal tract and a dog and a cat, I think even lay people listening understand that horses eat grass and, you know what I mean, grains, and hay, and things. They eat some different substances, but can you talk a little bit about that?

18:16 DH: Yes, you're quite right. Unlike us, they're able to get all their nutrients from eating grass and forage, and the reason they are is they have this wonderful symbiotic relationship with all these multitude of microbes in their gut. And they are similar in a way to the cow that also uses a lot of these fermentation, but unlike a cow, the horse is fundamentally a hindgut fermenter, which means... I often use to describe that if you want to think about how to feed a horse, you think of putting the front half of a dog and you attach it... of the digestive tract of a dog, I would say, to the front half of a cow, because the first part is a monogastric and then we go into basically, a fermenting vat. But it really isn't as simple as that, as you said, and just a few things.

19:09 DH: So, we start off just looking at the head of the horse compared to the dog, it's very big. And that's partly because they have these teeth that work together to grind the grass to release the soluble components that then can be digested, as if they were being fed to your dog in that small intestine. But if we look at just the stomach, so the stomach of a horse is comparatively small. It only forms about 9% of the GIT tract, whereas in the dog, it's about 60%. And that is because the horse evolved to eat almost constantly. It's a trickle feeder. It would eat a few, move, eat a bit, move, and it would eat for 15, 16 hours a day, it would spend eating with relatively small breaks.

20:01 DH: So and also the little things, like the horse can't vomit, unlike dogs and cats, because it has a very strong entrance sphincter to the stomach. But then we go along the track very quickly, and the small intestine is comparatively short. And the reason that's important, it means that if you feed a horse a large meal, it has to leave the stomach quickly and it has to go through the stomach, the small intestine very quickly, which means it hits that hind gut fermenting vat very quickly, and there's very little time then for digestion. And that's why we feed horses small meals, little and often. It's all to try and work with this, how this gut works.

20:44 DH: And then we go into the hind gut and again, compared to your dog, your dog, it's about 15% of the gut in the dog, but it's 60% in the horse. And that's because food stays here a long time in order for those microbes to ferment, to enable all those, the goodness and the calories and the nutrients to be released. But we have to remember that the horse, we're learning again, more and more, that these microbes are all throughout the gut, especially in the stomach. So if we feed them a lot of starch and sugar that's freely available, we get that fermentation in the stomach occurring and we get an increased risk of gastric ulceration. So again, we learn that how we feed and what we feed and when we feed can have an effect right along the tract to the horse. And it's all because of these differences or unique characteristics of why we need to feed like this.

21:41 DH: And then finally, the horse's guts, you've got a massive amount of gut in order to happen pushed in a very small space, and then we ask that horse to jump and to run. And it is very complex, and we have large tubes going into small-bore tubes and we do right-angle turns. And this is why feeding and how we feed and the risks of feeding are perhaps one of the reasons we have a potential increased risk of colic and abdominal disturbances in the horse. So that's a real whistle-stop tour of the horse's gut.


22:23 DD: That was perfect. I wanted to ask you, thinking back on obesity is, let's face it, there's tons of diets and weight-loss programs for people, and we're seeing more in dogs and cats, but what is a weight-loss program? What do you tell people if you've determined their horse is overweight or obese? Like where does a weight-loss program even start for those guys?

22:51 DH: Yeah. And this is a complex... And I'll only be able to touch on a few points of it. But to be honest, the first is that you have to recognize that the horse and pony needs to lose weight. It does sound so simple and obvious, but it really is key, because these weight-loss programs can be very difficult for both the owner and the horse and pony. So you do need to be committed, and often it can be really helpful to work with a nutritionist, with your veterinarian, with your friends and colleagues, because you will need support. Some of these programs, it's very difficult, and we'll pick up on why later on perhaps. The other important thing is you're right, every program needs to be tailored to the individual animal because it has to be tailored to the environment, how much weight the animal needs to lose, and what facilities and time commitment and resources are available to the owner. It has to be able to work.

23:52 DH: And certainly, when you have the very obese animals or those that are prone to laminitis, we definitely need to think about getting veterinary and nutrition advice. But in essence, it's pretty fundamental in that we need to either reduce energy intake and we need to promote wherever possible an increase in energy expenditure. So the easiest one is to think perhaps about the energy expenditure, and it picks up on what I said before. So that might be just use winter to help you plan your weight-loss program. Use winter by not rugging for warmth, and wherever possible and you might need veterinary advice, increasing exercise because those are the simple things. Go for a walk with the horse, even if it can be harder work, but just go for multiple walks. It's great for you and great for the horse.

24:48 DH: And then I think in addition to thinking about energy intake and energy expenditure, we also need to think about what we feed through a weight-loss program, and you picked up about the diabetes. And although horses rarely suffer, but they do suffer from insulin dysregulation. And I said, "Obese animals are more at risk of insulin dysregulation." So we tend to recommend when you're on a weight-loss diet, we're really trying to also put you on a diet that's low in sugar, low in starch, and doesn't promote those increases in insulin. So do you want me to go through, so roughly how I would start, or is that enough?

25:32 DD: Yeah. No. That would be good. And maybe as you're... You just alluded to this, is some of the challenges. So maybe as you talk about how you start, you can also work in some of the challenges that people face at each... At stages as well. I know that's a big ask, but that might be great for people to know as you're moving, what challenges you might think through.

25:58 DH: Yeah. So we'll pick them up and then I can maybe emphasize them at the end as well. But, if we start with an animal that's overweight or obese with all the other caveats I've mentioned before, the first thing is that for some, it may be relatively simple and you may just make some small changes to the diet and it can work, so that you start by looking, the same for us, at the overall diet. And, if your horse or pony is overweight, but you're still feeding them a manufactured diet, and you're feeding them plenty of hay and any other fiber sources, think about simply just replacing that manufactured diet with one that provides a lower energy. Again, going for a high fiber, low starch, low sugar food. And again, ideally try and look for one that's actually been formulated to help promote weight loss and yet maximize the time spent chewing, because we've said horses evolved to spend 15 plus hours foraging, chewing. And we also want them, as I said, not to promote that insulin response.

27:05 DH: Alternatively, in fact, the vast majority of many, many horses and ponies, even those that are doing work, can actually be fed on forage alone, and an appropriate forage balancer. So, you can take them off the manufactured food and put them on an appropriate forage balancer. And by that, I'm talking about something that matches and provides their vitamins and minerals. And then depending on your forage, may also need additional protein so that you support the essential amino acids, which is really important into the weight loss program, because we want to try and minimize the muscle loss that occurs at the same time as you lose fat. And then, look at what forage you're feeding. Think of that. If you're necessary, change to one that is a lower energy forage, so you want to think about things like the late cut, more mature hay.

28:00 DH: You want to avoid things like alfalfa, or immature hay, or haylages, and you obviously want to avoid those with high sugar contents. There are some caveats though, you do need to be a little bit cautious when you feed very poorly digested high lignin foragers, especially when you're feeding really high amounts, other than to donkeys. Donkeys do very well on things like straw. Donkeys were evolved to live on forages such as that. But if in other animals, you need to, they can be used, but you need to use them, introduce them gradually and carefully, and there is a risk of impaction and gastric ulcers. So, I'm afraid to say that even in this stage, you're probably talking about reducing access to grass, because these animals will eat, and grass can provide a lot of calories.

28:57 DH: But if possible, it's advantageous to maintain some turn out, so you could use for example, appropriately restrictive but not complete exclusion grazing muzzles. And we would be recommending that you should use them all the time as part of your weight management program, if you're turning them out. You should use them all the time you turn them out, because one of the problems is that if you take a grazing muzzle off and you leave them out in grass, some ponies will decide to eat more and make up for the fact you're restricting them. It is important. You can think about strip grazing, you can think about mowing the grass and removing the clippings. You could put wood chips over a small paddock. You can use dry lots, indoor schools. Basically, there are a multiple ways you can do to reduce that intake. Each of them have pros and cons, and I can't go into detail, but it is important to check with someone before you choose one of those that you know what are the limitations.

30:03 DH: For example, grazing muzzles, they can be brilliant, but the animal must be adapted wearing them. They have to be able to eat through them, they have to be able to access to grass, to water. They have to be checked regularly. They have to fit, and you have to think that they won't work always on all types of grass, because if the grass is too long, they can't get it through the hole, if it's too short, they can't get access to it. So, there are a lot of information around that there is there for owners to use.

30:38 DH: That's your basic, and that's something that I think all owners can do with advice. There are some animals, however, that we have to be more restrictive, even from the beginning, and these are the very severe animals or those that are really prone to laminitis. And these are the ones that we have to restrict quite considerably. And I would recommend this is done again, often with veterinarian nutrition advice. So we may go down, I don't suggest we go any lower, but we might go down to 1% of the body weight in dry matter per day.

31:16 DH: Now, if you remember a long time ago, but I mentioned that ponies could eat 1% of their body weight in dry matter in three hours. Now, one of the challenges is that horses are actually hot-wired to eat forage, so by restricting them, you are causing both behavioral and potentially physiological issues. So when we start on these really low levels, we have to think of methods to increase the time they spend chewing. We have to think of things like slow feeders, double hay nets, haylage nets, and ways that we can try and support them through that. Very important to give them vitamin and mineral support as I said before. Very important that if you go to that 1%, which some you do need to, we usually suggest we start at 1.5% of dry matter body weight. If that isn't working after four to six weeks, we go down to 1.25% and then with veterinary advice perhaps down to 1%, but those are the more restrictive...

32:31 DH: Just if there are vets on the call, a couple of points, if you're using soaked hay, you will lose a variable amount of sugar, but you will also lose some dry matter. So you need to allow... You ideally test, but in general, about 20% additional, because you'll lose up to 20% of dry matter by soaking. And then one other little factor for vets and owners to be aware of, is that during... If you have a very obese animal, in the early stages of a weight-loss program, you may see no change in their body condition score, and that's because in these very obese animals, we think they lose first from their internal fat. So you need to be aware of that because you might not realize that they actually are losing weight, and we do not want to make too severe a restriction. So in those animals, I always recommend that in very obese animals, we monitor heart girth, belly girth, rump width, as well as body condition score, and ideally, periodically go onto a calibrated weighbridge. So those are kind of the things that we need to think about.

33:53 DD: Right. Well, that's pretty... That's really awesome and some really great advice, I think, for folks because you touched on a lot of the... I think what I see in the popular literature and what we see at Morris when we get grants. This is some of those strategies I've seen come through over the last few years, and that brings me to my next question which is, what kind of new information is out there that we're learning about obesity in horses? You mentioned a few, and where do you think the research is going? Like what are people really interested in looking at right now?

34:30 DH: Well, to be honest, there's a lot of interest because it's obvious, there's this global issue, and therefore it is really important. So there are many aspects. So probably if I can just touch on a few that we're working on that to perhaps give a flavor. So one of the ones that I think is really interesting is that we've shown during these weight-loss programs that I've just been describing, even the more restrictive ones that I say need to be done under veterinary control, the amount of weight that's lost is very individual and there are some horses and ponies that are very weight loss-sensitive, I.e., they lose weight with those relatively mild restrictions. But there are others that are actually very weight loss-resistant, and these are the ones that really need those more severe diets that you might have to really... We need to put in these other things in place to support the animals during those diets.

35:28 DH: And together recently with colleagues now based at SRUK in Scotland, we've actually found some very interesting preliminary evidence that these weight loss-resistant animals may be able to increase their ability to digest fiber, and this is because of differences or they are able to make differences in their gut bacteria. And we've actually been able to now find some differences in their feces before they started the diet, which might lead us to the future to being able to determine before you start a diet, whether you have to go down those very severe or less-restrictive practices. So I think that is really exciting. It's novel and new, and I think it builds on the fact that we're all trying to understand what all those microbes that I mentioned throughout the gut, what they're doing in the horse, how they link with performance and health, so very important.

36:26 DH: Secondly, I think you've gathered, I'm very interested in the practical ways of helping owners because I've got a fat pony that I manage, and it is very difficult when you're trying to manage multiple animals without a lot of resources. And so we've been working, for example, in America with the University of Maryland about some of the practical ways to use grazing muzzles, and we've also been trying to look at practically how we can use things like strip-grazing. Does it work? And we've recently just completed a study with Dr. Longland in the UK that says if we use it appropriately, it can actually be very effective at weight management. So these are the kind of practical guides.

37:11 DH: And then I think we're trying to understand what are the implications of weight management. So working again, some areas in the University of Kentucky in America, we've looked at the effect of weight-loss on bone mineral content and we've looked previously at the effect on muscle. And I think for me, some work we've done with the University of Melbourne has been looking at what practical amounts of exercise do we need to add in that will help because we know it helps protect bone and muscle and it improves insulin sensitivity, but what level is practical to owners and horses. And there's a lot more work that needs to be done there.

37:54 DH: And then finally, or not finally, I think it's just an area that's really, really important, is how we should be feeding these animals? Exactly what are the best diets? How do we get their calories? How do we support them? How do we give them their vitamins and minerals in a way that works optimally for these very obese, very insulin dysregulating? And we're working with universities around the world in Kentucky, Michigan, Minnesota, as well as Melbourne and the RVC in England, lots of places, because this is really, really important. And it's important because we have to realize that, for example, as I said to you, this hot wiring of the horse to chew. So if we restrict ponies, for example, and we put them out on a dry lot, absolutely fine. But if there are poisonous plants or toxic plants there that normally they wouldn't eat, one of the risks, of course, is that they will eat it when they are being restricted in fiber.

38:52 DH: So you do have to be very, very careful. I forgot to mention that, really careful with that. And also, if you're putting a small amount of fiber on sandy soils, very good at... Not much grass, but it's risk of sand colic. And you don't even get it away if you put them in a stable because some of them, you have to be careful make their bedding and even wood shavings. So it isn't something... We ought really need to all work together to work this out.

39:22 DH: So I think you asked, what do I think of the future and where we should go? I think I've mentioned before, I think the role of the microbes in the gut, and I think that's really important, and I think it's exciting to perhaps look at this in weight loss and weight gain. I would say we also need to support these welfare-friendly practical solutions that owners can use in real life that help them, and I think we need to work that out and make sure we come up with programs that people can use, a bit like the Body Condition Index that are practical. But for me, if I look at it as a scientist working in the area, we still really need to understand the link between diet, obesity, insulin dysregulation, and laminitis. That is key, so that we can give the best advice to everybody who has ponies, horses and especially those that are prone to laminitis.

40:27 DD: If you had to have a take-home message for our listeners who are horse owners and are equine veterinarians out there about obesity in horses, what would you distill things down to?

40:42 DH: I think I would say that it's really difficult to promote weight loss. It's certainly in some individual horses and ponies once they become obese, so my main message would be, the best way to manage an obese horse or pony is actually to prevent it becoming obese in the first place. I would really put an appeal out that it's really important as you started, to recognize when our animals are starting to put on weight, so that we can put appropriate managing and feeding strategies in place as soon as possible. I think they will be my main, and then really for all you owners out there, it's important that every weight loss program is targeted, and it can take a lot of time and effort but it really is worth it if you can help your animal to get to a more ideal body weight. And then, my final message would be, is that once you reach that ideal body weight, you need to keep monitoring. You need to keep on monitoring. So again, we do a program of weight maintenance and reach out. And certainly if there's anybody, I don't know how you do it, there are a lot of references I can give and some helpful... If there's a way I can provide that.

41:57 DD: Yeah. Actually, Pat, if you want to send them to us, we can post them along with the podcast, so that would be great. Thanks so much for joining us today and telling us about this really important issue in horses, and we'll look forward to reading more of your work on this topic in the future.

42:16 DH: Thank you so much for the opportunity, I really appreciate it. It's been great to share on something that is really close to my heart and such an important issue for the horses and ponies around the world.

42:27 DD: Well, thanks again, Pat. So that does it for this episode of Fresh Scoop, and once again, thanks to Pat for popping on the podcast with us, and we'll be back with another episode next month that we hope you'll find just as informative. The science of animal health is ever changing and veterinarians need cutting edge research information to give their patients the best possible care, and that's why we're here. You can find us on iTunesSpotifyGoogle Play Music, and Stitcher. And if you like today's episode, we'd really appreciate it if you could take a moment to rate us, because that will help others find our podcast. To learn more about Morris Animal Foundation's work again, go to, and there you'll see just how we bridge science and resources to advance the health of animals. You can also follow us on FacebookTwitter, and Instagram. I'm Dr. Kelly Diehl, and we'll talk soon.



Sign up for our emails and get the latest animal health news straight to your inbox.