A properly fit heart-bar shoe should transfer weight to the back of the horse’s foot. When the foot is off the ground, there should be little to no pressure between the shoe at the toe (illustrated here by sliding a ruler between the shoe and foot).

A serious affliction of horses today is laminitis and founder. When a horse has laminitis, the toe or front half of the foot is in pain because the laminae that adheres the hoof wall to the bone has become inflamed. This is a problem because the hoof wall supports the weight of the animal. The connective tissue between the bone and hoof wall is now compromised. Founder is worse because the laminae actually tears and the weight of the horse causes the bone to sink within the foot.

There are proven treatments that can offer relief to a horse afflicted with this condition. In order to arrest the sinking of the coffin bone (in cases of founder) or simply to alleviate pain (in a case of laminitis), weight may be transferred to the back half of the foot (specifically over the frog). To do this, a frog-support shoe, or heart-bar shoe, is applied to the foot.

The question is: How much pressure is needed to alleviate the pain in the front half of the foot while not creating more pain in the back half of the foot over the frog? If a heart-bar shoe is fit with too much pressure on the frog, it may create more pain for the horse. This can be compared to a person wearing shoes that are too tight. Over time the problem will just get worse. If a heart-bar shoe is applied with not enough pressure, the shoe will not have the desired effect of stopping the bone from sinking (founder) or of relieving the pain on the front half of the foot (laminitis).

Some farriers wonder about the usefulness of heart-bar pads. Unfortunately, some get the idea that the amount of pressure will automatically “take care of itself”. They think that because the pad is made of soft material like plastic or rubber instead of steel, the amount of pressure will adjust to a horse’s individual needs. The pad alone cannot do this. A pad must be fit properly with the horse’s comfort as the farrier’s goal. The truth is a pad alone (such as a frog support that is taped or glued to the foot) can sometimes do more damage than good. The pad may shift and put pressure in the wrong place. Shoes have a tendency to be a more secure fit.

Simply putting a frog-support pad between a shoe and foot will not fix the problem. The idea of just putting a pad on that magically applies the perfect amount of pressure is appealing. Farriers wouldn’t have to learn the extra skill of making or fitting heart-bar shoes and they wouldn’t have to learn to read the horse’s body language. But farriers must learn to read a horse’s response to pressure. To make this easier, it is a good idea to shoe the horse when it is not on bute, or other painkillers, that may mask the horse’s response to fitting the frog-support shoe or pad.

When a shoe or pad is fit too tight, a horse will exhibit signs of discomfort. It may clench its lips shut or squint its eyes. It may quickly pick its foot up and not put weight on the newly-fit shoe. If this happens, it is best to take the shoe off and readjust it. Do not leave a shoe on that is causing the horse obvious signs of discomfort! When a shoe or pad is fit correctly, the horse will exhibit signs of relief. Most notably, it will lick its lips and chew as well as sigh deeply when it feels better. Also, watch for the horse to load or weight the foot and relax the feet that have been taking the load for so long.

The weight of the horse should also be considered when fitting the appropriate amount of frog support. A heavy horse may need less pressure applied because the weight of the horse’s load will add to the amount of pressure over the frog. A lighter horse (or a pony) may need more pressure applied mechanically, because the weight of the animal will do little to contribute to the amount of pressure over the frog. Farriers must gain a lot of experience to learn the correct amount of pressure to apply. Taking on therapeutic cases before you have this experience is unwise.

Whether using a frog-support pad or heart-bar shoe, farriers must fit them to each horse’s individual needs. What works for one horse may not work for another. The horse’s comfort is the goal. If the horse can get comfortable, it can begin to heal.