What is considered to be a "Flat Footed Horse"?
Well, anatomically, the hoof capsule should be a "cozie" for the foot, the P3, inside the capsule. Much like those soda-pop "cozies" that are supposed to keep your drink cold.
Do you see how this cozie wraps right around this soda pop can? No separation between the cozie and the can; hugs the shape of the can perfectly; protects the soda can from outside influences - just as the hoof capsule SHOULD do for the inner foot of the hoof!
Let's take a look at a dissection of a relatively healthy hoof:
I've drawn in the hoof wall line to show where it would be on this hoof as the wall was removed in the dissection. But you can clearly see how tightly the capsule fits onto the foot - and how the capsule molds to the foot as the cozie does on the soda can.
Now, let's take a look at the bottom of the Coffin Bone ... a dissection to show the actual shape of the 'foot' (inner).
You can see clearly how the bottom of the corium that lines the coffin bone is a concave shape -- almost a shallow "bowl shape". The sole of the hoof should mimic this in concavity on a healthy hoof.
Keep in mind that not ALL hooves are created equal! Just as with your feet or mine, ours differ from one another. So not everyone has a clear 'arch' to his foot. In fact, some are downright 'flat footed'.
This can be the same for horses.
That being said, we don't trim our FEET as we do trim horse's hooves! In other words we aren't shaving off the bottoms of our feet every 4 to 6 weeks! We leave our own soles alone. If we are barefoot much of the time then we develop calluses that will thicken our soles - the same way horses will do on their hooves.
Now there are a few different reasons that a horse might be flat footed.
Defining "flat footed" - the sole of the hoof is more flat than concave. A flat-footed horse is walking on the sole of his foot as well as on the hoof wall and frog. ... In MOST cases, flat feet are the result of poor or incorrect farrier care.
In the photo below we see a very flat-footed hoof:
(Photo courtesy of Nick Hill, V&T Equine Services)
There are other issues with this hoof that is shown besides being flat-footed but suffice to say that the reason behind this lack of concavity is man-made from incorrect farrier service. The sole has repeatedly been trimmed away so that the sole is very thin; not like the robust sole you see in the illustration in the paragraph above. In fact, it almost appears as if this sole is convex instead of concave. I imagine this horse is not very comfortable on its hooves.
This hoof, below, shows another flat foot but flat-footed for an entirely different reason:
(PENZANCE Equine Solutions)
This horse has built up callus on its sole to protect the foot from excessive concussion and impact of rocky ground. This horse lives on very rocky ground. If it had a thin sole that was flat then movement would be very painful for this horse.
Now one has to envision what happens to as hoof when it is loading with thousands of pounds of pressure per square inch resulting from the impact of the weight of the horse. As the bony column descends into the capsule, the P3, the coffin bone, is thrust down onto the sole of the hoof as the rest of the hoof expands and 'gives' to the pressure. This allows blood flow to help cushion the blow. While the back 2/3rds of the hoof is protected by soft tissue, the sole of the hoof is hard, keratinized protein that has little 'give' to it. There is soft tissue that surrounds the P3 in the foot but not as much as in the back of the hoof with the frog and the digital cushion. The sole acts much like a 'stop' for the hard descent of the foot in the capsule. As the hoof grows the foot becomes more and more protected by the wall and the sole. The thinnest part of the sole, by the way, is right around the apex of the frog .... just behind the tip of the coffin bone. The tip of the coffin bone lies about 3/4's of an inch in front of the apex. When this area and the sole directly under the coffin bone is constantly trimmed away, when the callus that builds is constantly trimmed away, the sole thins and becomes inadequate to protect the foot as the coffin bone descends closer and closer to the ground. Thus, the bottom of the hoof appears flat.
Compare the flat footed illustration with this very healthy, concave hoof:
(Photo courtesy of Marjorie Smith, barefoothorse.com)
In that photo you can very clearly see the concavity of the sole ... mimicking the bottom of the P3 in the foot very nicely. The P3 is nicely tucked up inside the capsule away from harsh impact of varied ground surfaces and allows for adequate expansion of the hoof for correct functioning of that hoof.
This concavity is not something that can be 'carved' into the hoof. It must be allowed to develop with proper care, trimming and diet.
Yes, diet can contribute to the failing of the sole of the hoof. Too much sugar and other insults in the diet will weaken the hoof so that, not only the horn, itself, will be compromised but also the growth factor and the functioning of the hoof. This will easily result in flat hooves.
Flat feet can also be caused by a genetic disposition. As I mentioned at the start, not all hooves are created equal. Some are simply inherited from the sire's or dam's line of genetics.
Mostly, though, as stated, flat feet are the result of incorrect trimming of the hooves. The sole will exfoliate itself and form itself nicely if the horse gets appropriate exercise/movement. If the hooves are treated correctly during trims, balanced nicely and the horse is ridden correctly as well as allowed to get enough free movement, the hooves will adapt and tend to themselves nicely.
If you have a horse with flat feet it might be advisable to ride in hoof boots to protect that sole from bruising and other debilitating injuries. Leave the soles to thicken so they can provide that essential protection to the foot that is perfectly designed from the get-go. Just look at these little beauties!
Gwenyth Browning Jones Santagate is the world-renown author of "10 Secrets to Healthy Hooves" and "Natural Hoof Anthology" as well as a noted author for various international equine publications including The Horses Hoof, Equine Wellness, Natural Horse Planet as well as a contributing author for the 2001 United States Federal Mounted Border Patrol Training Manual. For the last 37+ years, she has maintained healthy hooves with natural trimming on thousands of horses and specialized in pathological rehabilitation hoofcare for the last 18 years. She and her husband John keep a small herd of their own equine in NE Connecticut and continue to offer consults for horses in need. For further information please click here: www.thepenzancehorse.com
Gwenyth is available for freelance assignments, contract work and consulting.