All right, welcome back to the second lecture of week two, and this lecture is hoof anatomy. And, you know, we devote, you know, the next three lectures really just focusing on the hoof because it is so critical to their care that, you know, it's really worth while to pay attention to these lectures and hopefully, give you some tips. So, you know, it's really important to maintain a horse's hoof. And, you know, it's really critical to their ability to move, you know? So, if you're competing with this horse or any type of activity, if something's wrong with their feet, they're not going to be able to go anywhere. And it's just, it's really critical to their, to their, you know, health and well being, because, the old adage or the old saying is no hoof, no horse. And you know, I'm going to use Barbaro as an example, and we're going to get in much more detail when we get in the laminitis talk. You know, Barbaro is a story that happened in 2006 in the United States. He had won the Kentucky Derby. Spectacular horse, people really thought he was the next great chance for a triple crown. In the initial stretch of the Preakness Stakes, he breaks his hind right leg. And what happened was his hind right leg healed fine. It's just he started going laminitic in all the rest of his feet. And so, that, that's what really led to his demise. And he was euthanized in January of 2007. So, you know that's what directly caused him to, to no longer be able to live, you know, he had no feet. Now, looking at anatomy, you know, we're going to start on the outside and work our way in. And the first portion is just this outer hoof portion, and this is what we call insensitive, or epidermal, tissue. Now, it's insensitive because it doesn't have the nerve structure or really a lot of blood flowing in those areas, and I like to, to tell students that it, it's almost like your long fingernails. You know, we clip our, our long fingernails all the time, and we don't feel anything. You know, as long as it's the, the dead portion or out, outgrowth portion, which is very similar to the horse. So that's why we're able to put on, nail shoes on, or, or trim their feet, and they, they feel no discomfort whatsoever. Now, the bottom of the hoof anatomy is really, really important to, to know different structures. So, it's worth while to review this slide in detail. You know, if you ever get in discussions with a fairer or your veterinarian, you need to know, you know, what he or she is referencing to. Now, just looking at the, the external part, you know, divide the hoof into really three parts, and the first portion is called the toe. So you can see here, the next portion is the quarters. And then there is this, this final portion is what we call the heel. So, we'll say heels, quarters, toe in reference to that. And just going around, this right here, which I'll highlight in later slides too, is called the frog. We'll talk about that. You know, here's the bars of the frog in here. Most of this area, you know, is the sole. So, you're looking at, you know, all the way through here is, is really the, the concave portion of the hoof, and then this outer portion, or the hoof wall, you know, is really going all the way around. And we'll talk about that too, especially when we talk about hoof care, but that's where the horse rests, or should be resting, most of their weight. They shouldn't be resting weight on the sole or the frog, that outer wall should really be the part that's protruding down. So, and we'll get to that when we talk about hoof care. Now, in this slide, I just put up the bottom of a hoof and just wanted to see if you could identify some structures on your own. So you can pause the video and try to go back through that, and just compare it to an actual hoof on this slide and to the previous one, with all the different structures, and see if you can find them on that. Now one, one portion I did not talk about in the previous slide is this area that you can kind of see starting right here, and it goes all the way around. And that's going to help lead us into, you know, talking about the internal structure. But that's called the white line. And the white line is where you get you know, the the inner hoof wall combining with the outer hoof wall. Now, the coronary band is this region right here, which you can see at the top of this hoof. Okay. And that's almost like our nail bed. So, that's where the hoof grows out. So, starting from there growing down is where the hoof kind of originates. So, if we look at our own nail beds, you know, that's kind of very similar to the coronary band. Now, it's important to remember if, if this gets injured or, you know, sometimes horses can clip their, their hooves when, you know, exercising or what not. You know, that can slow down or stop growth. So you always want to be careful if you do have a horse that has an injury there, to have a veterinarian or, or a fairer look at that area. Now, things that can affect hoof growth. You know, you can see the list there. And, and the two that I'll highlight is nutrition. And we know through research that, you know, hoof growth definitely has a, is affected by nutrition. And, and what we mean is, horses that have a higher plane of nutrition or they're, they have diets that are just higher in nutrients, they're going to have better hoof growth. And so, there are a bunch of supplements in different markets throughout the world that sells hoof promotants, and, and you know, some of these have research; some of these don't. But the general knowledge or the general rule of thumb is better nutrients equal better hoof growth. And then the other one I'll highlight really quickly too is the environment. In dry areas of the world or when it's dry times of the year, hoof growth is actually going to slow down. And then during more wet, you know, spring season or rainy season, those hooves are going to grow a little bit faster. Now, on average, a horse is going to grow, the hoof's going to grow about a quarter to have an inch per month. So, it takes anywhere from nine months to a year for a horse to fully grow out their hooves. Now, the other structure I really wanted to address on the outer hoof wall is this frog region, which you can see it outlined there. It's a little off center, but that, that's on purpose so you can visualize that. And the frog is the area of the hoof that is, I guess if you, if you said anywhere, an area was sensitive, it would be the frog. Now, there aren't, there isn't nerves running through there. But it's the softer portion of, of the outer hoof. So, it's made up of approximately 50% moisture. And, that's important because it really helps the hoof expand when they strike the ground. So it's almost the shock absorber. And it gives that hoof a little bit of its elasticity. So, when the horse hits the ground, that hoof actually kind of presses, compresses and spreads out. And that's why, you know, the frog with that moisture content can kind of do that. So, and when we get to talking about hoof care, we'll address the frog a little bit more, you know, on, on being careful trimming the frog, because you, you can injure it if you overdo it. Now, going from the outside to the inside, you know, the inside we call the sensitive tissue or the dermal layer, and you can see you know, that looks like that's pretty painful, you know, and obviously that was a horse that, that was euthanized at some point. But you can see the, the rich blood supply and that, when we call it sensitive, that also means that there's a lot of nerves there. So again, like the bottom of our nailbed. Anybody's that accidentally clipped their nails too short or pulled a nail, it's extremely painful. Well, that's because of all the nerves that are in there and very similar to a horse's hooves, you know that internal tissue. Now, I referenced the white line earlier, and if you looked at, you know, going from the external tissue to the internal tissue, it would be this region right here. So, you're, you're, you're looking at the portion where the outer hoof wall is attaching to the inner hoof, and that's through the laminar interface. So, they have these interlocking fingers that actually are really tight, even down at the microscopic level. And they keep everything in place. Now, also important with the, the, this laminar inter, interface is it attaches to the coffin bone. So, it keeps the coffin bone locked in at the proper angle, and it just really holds the entire, the hoof structure together. Now speaking of bones, these are three bones that make up the hoof wall. So we started with the short pastern or we call it the P2 or second phalanx, and then we have the navicular bone here, and then we have the coffin bone. So these are the bones that make up the hoof. Now, this long pastern bone is actually P1 for the first phalanx. And so that's really not part of the hoof, but that's coming down, you know, from the fetlock down to the pastern. Now, I'm only going to talk about two tendons, and before I do that, understand that tendons is the portion of the connective tissue that connects a muscle to a bone. Whereas, ligaments attach bone to bone. So, we talk about two really important tendons that are important in the hoof. And the first is the deep digital flexor tendon or the DDFT. And that attaches to the back of the coffin bone, here. So, we're looking right down here and actually, it's, it's up here where it attaches to the deep digital flexor muscle. Now, when that muscle contracts, so when we contract the muscle, we actually shorten it. Okay. So, you can imagine that's going to pull this tendon up, and this hoof is going to flex. So it flexes back. Okay. So it pulls it back. That's flexing. And that's from the deep digital flexor tendon. Now, the other one is the common digital extensor tendon. And so if you imagine up here the common digital extensor muscle actually contracts, so it's shortens and pulls up on this, and so the hoof is going to extend so extends out. And that's how those two tendons work. Now, there's other tendons running in there, and you know, the suspensory ligament and other things that, that are in part of the leg anatomy that are important because horses do get injuries there, but. So just be aware that, that there are a lot of, tendons and ligaments in there, keeping all the structures together, but these are the two that I just wanted to highlight. And then, the final slide kind of talking about hoof anatomy, and this will get important especially when we run into, start talking about laminitis is there's a really rich blood supply running down to the hoof, so you can see the, the the, you know, the many blood vessels running through there, and it's really critical, that helps those tissues, you know, grow and sustain themselves, and grow the hoof, so, when we get to laminitis, we'll know, we'll talk about the importance of that a little bit more in a couple lectures. So next, we're going to jump into hoof care. So I'll see you then. [BLANK_AUDIO]
