Rob Sigafoos is chief of farrier services and director of the Applied Polymer Research Laboratory at the New Bolton Center in Kennett Square, Pa. He is a graduate of the Oklahoma Farriers College and of the University of Pennsylvania School of Veterinary Medicine Advanced Farrier program. Sigafoos, who helped design shoes marketed by Soundness Technology, has been shoeing horses for 25 years and is considered an expert on glue-on shoes. We discussed common concerns when choosing glue-on shoes.
Horse Journal: What kind of horse would benefit from a glue-on shoe
Rob Sigafoos: Generally there are two groups: the therapeutic and the prophylactic. The therapeutic group consists of those horses that have hoof problems, such as thin hoof walls, lamenesses requiring this treatment, chronic problems or structural failure to the hoof wall because they have gotten into what I call, for lack of a better term, the “shoe-loss cycle.” This is where they lose a shoe and then the hoof wall is missing and the shoe is replaced and the second time the wall is a little weaker and the shoe does not stay on as well, and so on. As the wall continues to weaken, the shoe has to be fit on tighter and tighter and the horse’s foot will become misshapen.
The prophylactic category consists of horses owned by people who want to prevent problems. They want to be confident in adverse conditions that the shoes will stay. They want to be assured that there will be no damage to a horse’s feet, either because some horses just don’t tolerate nails or because they don’t want to worry about their horses getting stuck with a nail or other reasons.
A glue-on shoe is sort of like a postage stamp in that the load is distributed over a much wider area. Think about it, would a stamp stay on better if it were stapled on four sides, or glued directly to the envelope' Not long ago, researchers put strain gauges in the proximal end of the P1 (pastern) and measured the concussion impact at that point. They found that horses shod with a conventional nail-on shoe were experiencing more impact in that joint than they were when they were barefoot.
HJ: Does a horse wearing glue-on shoes have to wear them forever'
RS: It depends. The problem with glue-on shoes is that they are not a panacea. Certainly they make a big difference to horses that have really thin walls. For the horse that normally has a good thick healthy hoof wall but that somehow has gotten caught in the shoe-loss cycle or a horse that has hoof separation as a result of white-line infection, and there is a lot of wall loss as you see the wall grow out, then the horse wouldn’t necessarily need to stay in a glue-on shoe. The problem is if the horse has an inherently weak or thin hoof wall or doesn’t have good hoof structure or thickness to begin with, you are not going to change that. Our average horse wears glue-on shoes for about six months, but a lot of people put them on seasonally.
HJ: How soon after the horse is shod with glue-ons can it be ridden'
RS: Immediately. I have people that come over here riding in the rain, and I glue their horses’ shoes on and they ride their horses home in the rain, although I cringe when they do that because full cure on the adhesive is 12 hours. The cure profile is such that you get a rapid rate of curing in 10 minutes and then it plateaus out over time gradually until you get full cure in about 12 hours.
HJ: Can a horse easily jump and gallop in them'
RS: Oh yes. You may see glue-on shoes on race horses, hunters, event horses, dressage horses.
HJ: Can a horse be turned out in them' Do they pull off in the mud'
RS: They stay on better in the mud than a conventional shoe does.
HJ: What kind of damage would it do to the hoof if the shoe did pull off'
RS: Soundness Technology has a fabric fail-safe mechanism in case the horse gets caught in something. It is designed so the fabric will pull out of the urethane that is attaching it to the shoe. The fabric is still bonded to the hoof wall, but the shoe comes off. With a nail-on shoe, a horse actually can pull part of the wall off when he pulls a shoe. These glue-on shoes don’t damage the wall but actually leave a protective layer on the foot so that if the horse is walking around without a shoe for a while it has a protective layer.
With the Soundness Technology technique, we apply the glue to the sides of the hoof wall. Some people apply the glue directly to the bottom and apply a conventional shoe to the foot. We tried doing that many years ago when we were first getting started, and we just never had consistent luck with it.
HJ: Why do you no longer glue shoes directly to the feet'
RS: When I pulled a shoe off that had been on for four weeks and looked at the adhesion, I would see a complete adhesive failure. There was no adhesion on the bottom of the hoof wall, except for a bit in the heel area.
In fact, all I had to do to pull the shoes off was to hit them hard with a hammer. The trouble with this method is that it is really dependent on gluing the shoes to the heel. You have to glue the heels down thoroughly, and to me that’s a real problem because it puts tremendous pressure in the area where some horses have a lot of problems.
HJ: How often do glue-on shoes need to be reset and can you use the same glue-on shoes'
RS: They are reset in the same amount of time as a regular shoe. Some brands can be reset and some can’t.
HJ: If you decide to have your farrier apply glue-on shoes to your horse, what are the benchmarks of a job well done'
RS: Basically, you are looking for someone who takes the time to prepare the hoof well, who makes sure the foot is very clean, and who follows the procedures in the directions.
I think horseowners should have a copy of the directions and read it themselves so they can make sure they know what is going on.
HJ: What are the drawbacks to glue-on shoes'
RS: The fact that they are different. A lot of farriers don’t want to do anything other than conventional shoeing, and they may have a hard time accepting the difference in technology. That’s the biggest obstacle. Cost, too, is a factor.
HJ: How much do glue-ons cost'
RS: Total cost of the shoeing job is quite variable, depending on the shoe and the farrier’s charges, but it is considerably more than a conventional shoe. The farrier must charge more for labor. Properly applied glue-ons take more time to apply.