Healthy bars

Cindy had a very good question about my last hoof post: What do healthy bars look like?

In a nutshell:

• Healthy bars end at the midpoint of the frog
• they are straight instead of bowed
• they stand up, not pushed over onto the sole
• they are not so long and deep that you can't see the bottom of the collateral groove
• really healthy bars point toward the frog and not the toe

In detail: 

First we have to know what the internal bar structure looks like. In this photo you see a pretty nice hoof, the heels were nice and wide and the corium was healthy. You can see that the bar corium (outlined) angles in from the heels to the midpoint of the frog.

(I encourage you to click on these photos and zoom in to see the detail, they are important.)

Photo by Cheryl Henderson

In this, slightly less healthy, hoof you can see that the bar corium has started to angle toward the toe but they still end at the midpoint of the frog.

Photo from HP Hoofcare

 In this, really unhealthy, hoof you can see the bar corium (bright red) points straight toward the toe but they still end at the midpoint of the frog.

Photo from HP Hoofcare

What all these hooves have is common is that the bars all end at the midpoint of the frog. That is true whether they are healthy or terrible. So when I trim I try to get the bars to end at the midpoint of the frog- to keep the external structures similar to the internal structures.

The angle is a different story. You can tell by the above hooves that if the hoof is contracted and unhealthy the bars are going to point straight at the toe. You can't change this by trimming, only the full weight of the horse on the heels will get them to open up and point the bars toward the center of the hoof. What you can do is make sure the bars aren't so long they are digging into the hoof and aren't laid over so they are suffocating the sole. Essentially, you want to trim the bars to give the horse comfort; that will facilitate the hoof transforming into a healthy shape.

The following two photos show my second trim on a contracted hoof. I use the bar lamina to outline the bars from the heel turnaround (seat of corn) to the frog. I then try to make the bars as straight as possible and I slope them "downhill" from the heels to the frog. I do this so the bars are "passive," meaning that they don't bear weight which is especially important if the bars are impacted. While I do this I try to take off as little sole as possible, this can be a very time consuming process of taking off thin slivers at a time. It takes a sharp knife, a steady hand and lots of practice (I admit, I still need more practice) and can be made even harder by a fidgety horse. 

In this closer view of the above hoof, you can see the bar lamina as the demarcation between the inner/unpigmented bar wall and the sole. In this horse it's easy to see because the sole is slate colored.

If you can't see the lamina the bars are laid over the sole. If there is a black line along the bars it means they've laid over the sole and trapped dirt and thrush under them. That trapped dirt and thrush will destroy any sole underneath it, not good.

This next photo is after my first trim on a pony. The circled areas show bruising from overgrown bar, bruises that weren't visible until I started pulling the bar off the sole (Excess bar puts too much pressure on the corium below it, crushing blood vessels and creating these bruises.). Lots of horses have these bruises but you don't see them because the bar that causes the bruises also covers them up.

This last hoof is mostly healthy and shows little sign of contraction. You can see how the bars on this hoof angle in toward the frog instead of pointing down to the toes. I didn't make this happen, I just followed the bar lamina. These bars are pretty close to ideal, if your horse has bars that look like this chances are that horse is sound.

Bars should look similar to this

Here's a how-to guide to trimming bars similar to the way I trim: http://www.thehorseshoof.com/trimmingbasics3.html.

Questions? Please comment.

Contraction continued...

Before I get to the hooves in the photos I'd like to mention a few other factors that might play a part in hoof contraction:

• The weight of the horse: the heavier the horse, the less likely it is that their hooves are contracted. Drafts can have sorry, sad feet and still have very little contraction, small ponies and minis are the opposite.
• Movement: Allison had it quite right in her comment on my last post, movement is essential. Without movement and heel first landings the hooves will contract. Standing = stagnation.
• The hardness/softness of the surface they live on: hard surfaces offer more resistance to the hoof causing it to expand wider, soft surfaces are the opposite. Mud or soft sand can contribute to contraction.
• The moisture content of said surface: here's a bit of a contradiction to the last point, drier environments leave hooves more contracted than wet ones. This is because tissues tend to shrink when water isn't abundant. A healthy hoof in a desert environment will probably look more contracted than a healthy hoof in a more humid environment.
• Injury/disease: if one hoof is contracted, I would suspect an injury in the leg or disease in the hoof. Anything that makes it uncomfortable for the horse to land on that hoof correctly.
• Shoes: when the horse weights the hoof it expands, when they lift the hoof it contracts. In order to nail a shoe onto a hoof it has to be lifted- so the hoof is already at it's smallest when the shoe is nailed on. The nails will then interfere with the normal flexing of the hoof once the horse starts moving again, and if the nails are placed too far back they will interfere with the expansion of the heels. Shoes lock the hoof into its smallest (contracted) size which can get worse over time. I've heard there are farriers out there who can avoid this, but they are very, very few and far between.

Okay, onto the pictures.

Personally I think those hooves were contracted due to the pain from the bars (cue the broken record...). The bars are meant to give structure to the back of the hoof and to keep it from expanding too far upon impact with the ground. If the bars are left to grow unchecked, they can grow so long that, not only do they cause pain, they actually stop the back of the hoof from expanding. When the hoof can't expand all it can do is contract.

Lets look at some of those pictures a little closer, shall we?

The red lines outline the bars, the blue lines are there to show how deep they've grown into the hoof. Keep in mind that you can't see all of the bar, there's probably quite a bit that has been pushed up inside the hoof too. The accordion folds are a tell-tale of too long bars. Those are compression folds that are created when the too long bars get squeezed between the inside of the hoof and the ground.

I know there are some out there that still don't think bars need to be trimmed, all I can say is that every time I've trimmed off overgrown bars one of two things happen: they either start licking and chewing (a sign that a stressor was removed) or they pick up a hoof I haven't gotten to yet and ask me to do that one too. I imagine the horses in the photos would react the same way.

GRAPHIC: Dissection of hoof with impacted bars

I did not do this dissection, I found them posted on one of the list serves I follow. I wanted to show you these because it's one of the best dissections I've seen that show impacted bars in a horse hoof.

For any of you that may think I go on like a broken record about trimming the bars, or for any Ramey/ less-is-more followers who happen to stumble across this blog, this hoof shows what could happen when the bars are left to grow unchecked.

The side view and x-ray for reference. This is obviously a founder, I would say a completely avoidable one if only the bars had been trimmed.

Everything under the pink area (digital cushion, corium, later cartilages, deep digital flexor tendon) is bar. Look at how they've squeezed the soft tissues into an incredibly small, tight space. How could the hoof possibly function normally when it's been squeezed like that? Can you also see how bars that have impacted like these will damage the DDFT where it travels around the navicular bone and connects to the coffin bone?

Yet another view showing just how tall the bars have gotten. That's almost 2 inches of bar!

I think this one is interesting. Even though the walls are probably only a half inch too long (keeping in mind the dead material over the sole), the bars are at least an inch-and-a-half too long! Somebody was obviously trimming the peripheral walls down on this horse but they probably didn't touch the bars for years, if ever- and the horse suffered for it.

Here's a refresher: The bars are part of the hoof wall. Just like the rest of the wall they are composed of an outer wall, an inner wall, and laminae. Since they are part of the wall they grow at the exact same rate as the rest of the wall and should be trimmed in like fashion. Horses don't grow bar over sole and around the frog because "the hoof needs it," that's a garbage statement. If they are not trimmed they have to go somewhere, so they either grow up into the hoof like on this horse (hello navicular and founder) or out over the sole (which will create underrun hooves in no time). If you do trim the bar and it pops back out, that again isn't proof that the "hoof needs it" because cell division doesn't work that way, what that proves is that the bar inside the hoof finally had some room to move out.

Someday I'll let this subject go, but as long as there are people parroting misinformation about the bars I can't. So long as there are hooves like this out there I can't. This horse could have been saved if only someone had trimmed those bars.