The Frog Of A Horses Hoof


This is another one of my I Love Hooves blogs.  And, why not?  We should all love our horse’s hooves!  No hoof, no horse, remember?

When I look at a horse’s hoof, I’m checking out the structures, the shoe fit, the shape, etc.   On first impression I make note of the health of the frog.  The frog is like a window into the inside of the hoof.  It can tell us so much.  To me, it’s amazing.  The inside of the hoof can be so complicated.  Even with x rays and ultrasound machines, it can be very hard to determine why a horse is lame if we suspect problems within the hoof.  I’m always 98% sure that if the frog is healthy I have a much greater chance of having a sound horse.  Here’s why:

A healthy frog is the result of good blood flow to the hoof, good nutrition, and good hoof care.  The above picture is from one of my pastured horses.  Sure, it’s a little dirty, but the overall health of the hoof is good.  When examining the frog I see a large, thick,  V-shaped structure.  This is where it’ll make contact with the ground when the horse moves about during the day.  The frog of this horse is pretty clean, not what we call too ratty.  If the horse is compromised in any way the frog will start to change and take on a ratty appearance.  This always causes me concern.  I wonder, what’s going on inside this hoof?

When I think a horse is having a frog problem, I first check the fit of the shoe.  When I was a child I was allowed to ride around with my farrier, Red Tomlinson. This seems a little crazy to me that at 10 years old I would beg to go with him on his rounds, and my parents would let me!  I was able to see so many horses and learn so much about the science of farrier work.  Red taught me how important it was to make the shoe fit the horse, not the horse fit the shoe.  I loved the sound of the hot fire, the clang of the anvil and even the smell of the hoof as the shoe burned the bottom of the hoof during a hot shoe fit.  Even then I knew it was important to make that shoe fit the horse if Red put it in a fire to get just the right adjustment.  Today, my farrier Troy, is just as adamant about looking at the important features of a good fitting shoe.  Is there a quarter roll along the back edge of the shoe to allow for expansion of the heel of the hoof during the 6 weeks in between each farrier cycle?  Does the shoe extend farther past the heel of the horse to provide heel support to the leg?  Is the shoe wide enough to not cause soreness to the frog?  The back of the hoof is where all the blood flow comes into the hoof to feed the internal structures.  When these structures do not get enough blood flow, if the shoe pinches the heel, the internal structures change.  Does this sound familiar?

Your horse may be lame because loss of blood flow has caused changes to his navicular bone.  Navicular syndrome is such a painful diagnosis for the horse and the horse owner.  My dear friend and veterinarian, Dr. Cindi Lacroix, once told me that 95% of all lameness issues are caused by poor farrier work.  So I study even more…..

The quarter roll on the back of the heel is what allows for the heel to expand while the hoof is growing.  The name is such because it describes the look as though you could roll a quarter along the back top edge of the shoe.  The hoof is going to grow wider during the six week cycle, if the shoe does not allow for this expansion room, we compromise the blood flow.

The frog is the heart of the hoof.  By keeping the frog thick, the frog surface comes in contact with the ground as they walk about each day.  The pressing of the frog to the earth’s surface is called ambulatory compression and draws more blood flow to the hoof.

You can imagine the vicious cycle of compromise; poor blood flow diminishes the health of the frog, then the diminished frog creates less ambulatory compression. No wonder the inside structures begin to shrivel.

When I am trying to rehab a lame horse I often use a reverse shoe.  One of the best outcomes of this method is how the frog improves and lameness begins to diminish.

Hooves can be tricky.  But, the one thing I know is,  if the shoe fits, the frog will be healthy.  I really do have a hoof fetish!