Friday, January 10, 2014

Contracted Heels in a Horse

The foot in the first two images (Figure 1 and 2)  belongs to a horse with chronic heel pain. As a result of the chronic pain, the horse's heels are severely contracted and the base of the frog has atrophied (shrunk). In Figure 2, the width of the frog is highlighted by the blue line and the length of the frog is in yellow. Normally, the width of the widest portion of the frog is 2/3 of the total length of the frog (Figure 3).

Figure 1



Figure 2
 

Figure 3
In Figure 5 and 6, a normal foot demonstrates the normal ratio between the length of the base of the frog and the over all length of the frog.This is in stark contrast to the foot in Figures 1 and 2. Normally, a horse's foot lands heel first and transfers the ground forces from the base of the frog/digital cushion thru the body of the frog. As such, the frog and digital cushion play and important role as a shock absorber.  If the base of the frog is abnormally atrophied OR the frog is NOT making contact with the ground, the ground forces are transferred to the sole and wall of the foot creating a scenario for pain over the sole and bars of the foot. This may result in further heel contracture and continued foot pain!!

Figure 4
 

Figure 5
 The development of contracted heels and an atrophied frog can be due to poor conformation and/or chronic heel pain. The chronic pain prevents the horse from fully loading the heel region and engaging the frog properly.One of the most common conditions that results in heel contracture due to chronic heel pain is in horses with navicular syndrome. Unfortunately there is no magic treatment or shoeing that will significantly reduce heel contracture in these horses. In addition, once the base of the frog atrophies as in Figure 1, it is not likely that a normal frog will ever develop. Regardless, it is important to determine if these horses have heel pain and to treat accordingly. In my experience, shoeing these horses with a full pour-in pad or a frog-support pad is key to promote normal engagement of the frog. In addition, maximizing the "break-over" will allow these horses to land heel first yet shorten the time spent weight bearing over the heel region and thus reduce heel pain. An example of such a shoeing is in Figure 6. This shoe is known as a "Roller-motion" shoe which has maximum break-over built into the toe region of the shoe. In addition, a medium-grade pour-in pad has been included for the entire length of the frog.

Figure 6



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