Having experience in both training and hoof care, I’ve had the privilege of working with a good number of horses. Some horses came to me because the owner had hit a wall in training. Their horses had become resistant to what the owner was trying to teach. Others became so ring sour they completely refused to enter the ring or resorted to rearing, spinning away from the gate a/o bucking.
The first thing I look at are the feet. Don’t get me wrong there can be many things that cause resistance (saddle fit, type of bridle or bit, poor training techniques) but my experience has shown that many of these horses have a deterioration of the hoof. Take flaring for instance, the hoof wall pulls on the laminae and can cause pain in that area, or another common issue is thin soles caused by an over zealous hoof knife.
The most common hoof issue I’ve seen though, is deterioration of the frog area which is supposed to be the landing zone upon impact of the hoof. Many times I will find that the horse will soften up out side the ring on harder, more solid ground only to tighten up once we step back in to the ring’s softer footing.
Many people think softer footing would be easier on the foot and not be the cause of a horse’s discomfort. This would be true if the hoof was in good shape and the frog was not getting more pressure on it because of the deeper footing.
On some of these horses the central sulcus (the center area in the widest part of the frog) has a deep crevice (see picture below) that is a product of fungal infection and or lack of pressure from either the heels being to high or a shoe raising it off the ground.
Once your frog is compromised and deteriorating, more than likely the soft inner structure called the digital cushion, that also aids in shock absorption, is deteriorated also. Once the hoof sinks into the footing and adds pressure to this area the horse can become extremely uncomfortable. To further agitate the horse, this crevice will get sand in it and act as an abrasive on a soft tissue that is damaged and infected with bacteria.
Some people find it hard to identify lameness on a horse that is sore in two or more feet. Feel your horse. Ride them back and forth from soft to hard surface and don’t just feel the physical difference but also the mental difference in your horse.
On a final note your problem may not be in the hoof, but once you learn to feel and what to look for, it will be one more thing you can eliminate from your list of possibilities.
LEFT PICTURE This hoof pick, in the bottom of the picture, is inserted over one inch in depth into an area that is at the most supposed to have a slight indentation. Notice how narrow diseased and under developed this frog is.
RIGHT PICTURE Notice this frogs width, thickness and the outer callous protecting it. I can not remember the last time I had to trim this frog. If you were a horse what one would you want to walk around on. Shoe or no shoe, in sand or out of sand.