Because of the economics of raising and competing horses many disciplines are geared to the young horse. This, bluntly speaking, minimizes expenses used on a loser.

As a consequence, performance horses are started earlier, trained harder and shown more than ever before. Some disciplines now have a never-ending show season, so horses rarely get any extended time off.

It is no wonder then, that even the horses with the best conformation will exhibit problems during their competitive careers. These problems can occur from the tip of the nose to the heels of the hind feet and are often a combination of bone and soft-tissue issues.

Some common problems of the hind limb involve the foot and fall in the realm of farriery. In this age of specialization, some of these problems are breed or discipline specific. Let’s review some of the most common problems and how veterinarians and farriers cope with them together.

Conformation Flaws

Good basic conformation is the cornerstone of success of any top performance horse with a long career. Basically when evaluating a horse’s conformation, you are looking for symmetry and balance between the front end (head, neck, shoulders and front legs), the middle of the horse (the back from the whither to the loins) and the rear end (the loin, hip and hind legs). Ideally you want the withers and the top of the rump to be the same height, joined by a short-to-medium-length back supported by legs of appropriate size bone and a solid structure.

In most things, it is good to avoid extremes. Breeding horses is no exception. However we live in an age of extremes. The old axiom that if a little is good, a lot is even better, is seen more and more in horse circles.

Unfortunately, horse show judges dictate conformation trends — seemingly without regard for longevity. Consequently horse breeders often breed for specific characteristics that are popular with the judges of that breed, such as extreme height, a pretty head, flat top line, extravagant action and exaggerated muscling, rather than good basic bone structure.

It is not uncommon for a horse with less than ideal conformation to have a very brief spectacular career, only to break down, and then go to the breeding shed to produce more of the same type — that often have the same flaws that caused the breakdown.

The result is that equine healthcare professionals constantly face the challenge of dealing with the consequences of poor conformation in performance horses.

However, we cannot blame breeders for all the problems we encounter. Poor management, injury, poor shoeing and — finally — the inevitable aging process all take a toll.

The Role Of The Hind Leg

Even though front-end soreness is more common than hind-end soreness, good horsemen realize that horses in all disciplines shift their weight back and work off the hind end. That means a healthy, well-functioning hind end is essential to success. Different disciplines, by their nature, produce different stresses to the horse’s body. That means some hind-end lamenesses and problems are specific to a discipline.

Farriers must understand that only so much can be done with farriery to eliminate or help soundness issues. Our profession is linked hand-in-hand with the veterinary profession and a good outcome is often the result of a collaborative effort. The vet’s job is to help a horse medically and ours is to help it mechanically. Good communication and cooperation are the cornerstones to success.

Common Problems

We will start with the more obvious issues, then move on to the more obscure. There is an old saying, “When you hear hoof beats, think horses not zebras.”

Trainers or owners often ask farriers to address a perceived problem for a horse. The first thing to do is determine if what they are talking about is valid, which leg or legs are affected and the cause. A basic examination consists of visually checking for lameness at a walk, then picking up the feet to look for the obvious — such as a dislodged shoe or foreign material — and finally checking for heat, swelling or an increased digital pulse.

If the pain originates from the foot, a more thorough exam is necessary. Some problems are very obvious and others require that a rider get on the horse and demonstrate the issue.

Not Enough Foot

Shoes and pads are sometimes used to alleviate sore hinds — particularly when the soreness is due to the feet not having enough sole. The pads can be removed when the sole has regrown, or become tough enough that the horse doesn’t suffer any pain.

It is a given that adequate covering for the internal structures of the hoof is necessary for soundness. It is not uncommon to encounter a situation where a horse is sore because it was trimmed too short, its feet were worn too short or a shoe has pulled off with a good portion of the foot still attached.

Often horses are shod in front and left barefoot behind and only when they are short and sore do owners pay attention to the hind feet. Depending on the environment and condition of the foot, very often a simple fix such as a pair of open-heeled shoes is all that is needed.

However, when trying to nail a shoe on these compromised feet, your nails may encounter sensitive tissues. A safer solution is often to use either boots or glue-on shoes. We are entering a whole new era when gluing on shoes and using hoof boots is going to be a big part of the new norm.

Hot Nails

Any farrier who claims to have never stuck a horse is either not telling the truth or has not nailed many shoes on. With the number of nails we drive, it is inevitable that one will eventually go deeper than we want, resulting in a sore foot.

When this happens, farriers face two challenges. The first is finding the nail or nails and removing them, relieving the pain. The second is not to have the event lead to an abscess.

In the event of a nail stick, you can locate the offending nail by tapping on the clinch or using a hoof tester. Then remove the shoe, starting by straightening the clinches and pulling the nails individually with a crease nail puller.

Trying to pull an unclenched shoe can be very painful for the horse resulting in a violent struggle and making the stick even more painful.

I then gently use my hoof tester to localize the pain source. Often, removing the nail will bring significant relief immediately. Once the nail is out, I like to force Thrush Buster through the nail hole from the foot surface until it runs out the nail hole in the wall.

In the event that the stick was deep into the soft sensitive tissues, it may close up. This will prevent the Thrush Buster from coming through. This can lead to bacteria being trapped in the foot, which can lead to the formation of an abscess.

To prevent this, I drive a new nail back into the foot in the same channel, gently bending the point of nail that came through the wall tight to the foot. I then cut the nail head off so it is flush with the bottom of the foot.

I then use a 1/8-inch Dremel tool bit and drill down parallel on the outside of the nail, starting at the top and ending at the bottom. This opens a channel on the outside of the nail without disturbing any sensitive tissue. I then pull the nail back out from the bottom and treat it with Thrush Buster.

I then wrap the foot to keep it clean and instruct the caregiver to repeat the process for 3 days. I want the hole left open until the next shoeing cycle.

Bruising And Sore Heels

Pain localized to the sole is a common problem in all disciplines and breeds. The sole is the most at-risk structure due to its proximity to the ground and its structure. Ideally it is thick enough and tough enough to withstand the trauma it encounters, but occasionally it needs help.

For barefoot horses that are not in work, simply toughening up the sole may be all that is required. If the environment is abrasive, it may be necessary to soften the sole.

There are several solutions that will draw moisture out of the foot that work quite well. My favorite is Durasole.

In some circumstances, protection of the bottom of the foot requires the use of shoes and pads. Most farriers have their preferences of material in these cases. Mine is for plastic pads. The pad packing is as important as the pad in these cases. I used ultra-soft dental impression material mixed with copper sulfate powder. It must be put in the foot quickly, before setting up to prevent any pressure on any part of the foot. Often the pads can come off at the next shoeing cycle, if enough foot has grown in the interim.

Hock Wringing

Hock wringing occurs when the hock rotates outward during the stance phase. This often causes owners and trainers to panic. However many horses’ hocks twist when they bear weight. It is important to make sure the hind shoes are of adequate length and have adequate lateral support.

Attempting to totally stop the wringing by using excessive traction devices is contraindicated. Doing so may cause other problems.

Forging

Forging occurs when the hind foot comes forward and makes contact with the bottom of a front shoe, making a distinctive click of metal on metal; hence the term forging.

The number one cause of forging I see is low heels and a long toe in both the front and hind feet. This is easily corrected by standing the horse up, adding heel support and blunting the toes of the shoes on the rear feet and setting them back.

Every good shoeing job starts with well-prepared feet. In my opinion, that means a trim where the wings of the coffin bone are horizontal to the ground and the pitch of the distal edge of the coffin bone is 3 to 7 degrees from the horizontal, depending on the conformation of the individual horse.

You can only be absolutely certain of this with radiographs. This is a procedure that is rarely done with hind feet. I am constantly amazed at the number of negative palmar angles I have seen in radiographs of hind feet that outwardly looked ideal.

Another cause is “Lazy Rider” syndrome. Complacent riders often cause a horse to forge by allowing it to “go to sleep” while being ridden. A rider who keeps the horse engaged and moving forward can help solve the problem.

Slipping

Traction for the hind limb is a delicate matter of balance. You want to provide enough grip to keep horses on their feet, but not so much to cause the foot to be planted and unable to rotate when necessary. The most common cause of slipping is smooth, worn-out flat shoes. The simplest solution is to replace the worn-out shoes with new ones.

Traction devices range from none on most horses to 1 1/2-inch toe and heel calks on big draft pulling horses.

Here are some other common causes of slipping and their solutions.

• Slick barn aisles: Many barns have concrete aisles that were initially rough but have been worn smooth. A long-striding horse will often lose its footing behind and have to scramble to regain it. A solution is to fit the shoes with 1/8-inch tungsten carbide pins, set about 3/8 inch behind the end of the shoe crease. Leave it protruding about 1/8 inch and it will make a world of difference.
• Slippery arenas: Footing in arenas and show pens can vary from deep and heavy to hard and slippery. For horses that have to compete at fast speeds this can be a real challenge. For show hunters and jumpers, having correct traction while jumping is essential to a good round. Horses worried about footing tend to become very cautious, shorten their stride and lose their boldness to a fence. Observing shoes during competition where speed is involved will show that a variety of shoes can be successfully used on the same footing. When extra traction is needed, screw-in studs are the most common traction device. During training or in secure footing, they can be left out or used if needed. For barrel racers, a shoe that is a medium weight with good medial and lateral traction is a must. The most popular are aluminum shoes designed for barrel racers or light rim shoes.
• Slippery grass: Polo is one of the few competitions that is contested on grass any more. Polo rules mandate that only a standard-heeled shoe on the hind feet is allowed.
• Slick roads: Amish road horses and fox hunters are no strangers to slick roads. For them Drill-Tec is the standard method to gain traction.
• Ice: During northern winters, ice is a constant danger for horses and humans. One of the most common solutions for horses is the use of the drive-in Mustad ice studs. The usual configuration is three small studs across the toe and medium ones in the heels. The addition of rim or full snow pads completes the package.

Hind-Ankle Interfering

As the hind limbs of base-narrow horses get closer to the ground from the hips, the distance between the legs becomes shorter and shorter. In some, the limb-clearance distance is very small. There is the old adage that a fraction of an inch is as good as a mile — as long as they are clearing. This becomes a problem when, for a variety of reasons, the normal path of flight is changed so that the foot makes contact with the opposite ankle.

Put on your Sherlock Holmes cap before making any changes to the shoeing, because often, shoeing isn’t the problem. Instead, start by thoroughly critiquing your shoeing to confirm that the foot is properly trimmed and the shoes are correctly set. Unbalanced feet or shoes that were fitted too wide, have worn out or have spread can be the cause. If the shoeing is to your satisfaction, then start looking for other causes.

Bad riding is one of those causes. When a horse is moving on an arc, it’s important that his entire spine, especially his head, follow the same arc. The correct way to move a horse outward is from the inside leg of the rider. It is common to see the horse’s head being pulled to the outside in an effort to increase the radius or to keep him from cutting the corner. The hind limbs are on a smaller radius than the fronts, making them crossover faster, resulting in interference.

If you are satisfied that the shoeing or riding are not the cause, it is probably time to get the attending vet involved. The most common remaining cause is pain in the hocks or another physical issue.

In the event of hock problems, farriers have several options to help the horse mechanically until the hocks calm down. One is increasing the width of the outside branch of a shoe with fullering and thinning the inside branch. This will cause the inside branch to sink in the dirt more than the outside. You also want to fit the inside branch flush with the wall and safe it thoroughly to minimize contact.

 Another solution is the use of glue-on synthetic shoes. My favorite is the Polyflex sport horse hind shoe. The advantage is that it is ultra-light, which decreases the swing inertia. The other added advantage is that the inside is smooth and softer than steel, with no nails or clips protruding to rub on the opposite leg.