Equine enthusiasts are always evaluating the horse’s appearance, particularly if they are considering purchasing the animal. Conformation is the term used to describe this appearance and can be broken into principal categories of balance, structural correctness, muscling, and type. Of these, balance and structure are of highest importance when we assess most of our performance horses. Balance refers to equal distribution of weight from front to back and from top to bottom, as determined by angles and proportions of body parts. Structural correctness is critical for soundness and clean movement and is determined by proper bone alignment, particularly in the legs.
So how important is conformation when selecting a horse? Just as top human athletes possess certain body types that grant them athletic prowess, a well-balanced horse has smoother gaits and is better able to perform athletic maneuvers. Being structurally correct also greatly increases the horse’s likelihood of staying sound when his body is subjected to repeated concussive forces. So how do we look at a horse and analyze these important qualities?
What Is Conformation?
Conformation, according to Ted Stashak, DVM, who wrote The Horseowner’s Guide to Lameness, is the outline of a horse as dictated primarily by his bone and muscle structures. However, conformation is not just straight legs, it also is about the length of the bones, the angles of the joints, and the proportions and overall balance of the horse. Conformation is related to the breed and use of the horse. For example, a Quarter Horse used for Western pleasure will have a different ideal conformation than an Arabian used for saddleseat, especially in regard to desired muscling, length of neck and back, straightness of the top line and croup, and way of traveling. So, some aspects of conformation really do depend on breed and purpose. While it would be easier to fill the entire magazine with descriptions of desirable conformation for each breed or type of horse, instead we will concentrate on undesirable conformation, which practicaly is the same for all breeds.
How Do You Evaluate Conformation?
Conformation in horses should be evaluated carefully, and all good judges, veterinarians, and horse owners should have a system to prevent missing any aspect. Each person has a system which works for him, so if you are curious, ask a respected individual in your area, or attend a judging clinic.
To begin, we want to see that the horse’s parts are proportional. The horse’s body should be a square, and the neck, shoulder, back, and hip should all be approximately equal lengths, with the horse’s topline shorter than his underline. A common flaw that negatively affects the horse’s balance is a back that is long in proportion to his body. A too-long back makes it difficult for the horse to bring his hind legs up under his body as he moves. This causes him to distribute more weight on his front end, which reduces power and maneuverability, increases concussive forces on the front limbs, and causes a more jarring ride. Another important yet easy-to-determine criterion of balance is hip and wither height. These should be approximately the same. If a horse is built “downhill” he will carry more weight on his front end, causing the same problems mentioned above. However, when assessing young horses’ balance, remember they will grow faster at the hip than the withers and will appear built downhill at different points during growth. Slope of shoulder and “turn” of hip are two other factors we assess for balance to determine athleticism.
Slope of the shoulder measured from the withers to the point of the shoulder is ideally approximately 45° and directly influences the horse’s stride length and smoothness. Overly upright shoulders can cause the horse to have a short, jarring stride, whereas nicely sloped shoulders allow horses to reach farther with their front legs, offering a smoother ride. Balance of the hip is also critical to a horse’s athletic ability and power. A horse’s hip should be approximately the same length as its back and have a slope roughly the same as the shoulder. A horse with too flat or steep of a hip will lack range of motion needed to provide power.
What Are Conformation Faults?
Faults or flaws in conformation can occur in the forelegs, hindlegs, pelvis, head, and even the neck. For this article, we will mostly concentrate on faults of the fore and hind legs. These conditions are undesirable, not just because they don’t meet a breed standard, but because they cause inherent weakness in the legs and predispose the horse to lameness or injury. Many of these problems are present at birth or soon after, and they are correctable, if they are recognized. However, many of these faults go unnoticed until the horse is one or two years of age, and then it is too late to correct the problem. At that point, they are permanent baggage for the horse and the horse owner, leading to abnormal wear of the joints, tendons, and/or ligaments. Following are descriptions of common conformation faults (with the lay term in parentheses).
A club foot is a term that describes a hoof with a foot axis of 60 degrees or more. This condition can be acquired (developed ) or congenital (present at birth). This condition occurs almost exclusively in the forelegs. If the club foot is congenital, it results from a congenital flexural deformity “contracture” of the deep digital flexor tendon. An acquired club foot often is the result of an injury or condition that causes pain in the leg, resulting in disuse. The leg then develops a flexural deformity from the disuse, and the hoof changes shape as a result. An acquired club foot also can be the result of nutritional problems, leading to the same flexural deformity. Treatment is aimed at eliminating the inciting cause and returning the hoof to a normal angle through corrective trimming or shoeing.
Toed-In (Pigeon Toed)
This flaw is recognized when viewing the horse from the front. One or both hooves will point inward. The deviation can begin at the shoulder or hip, or as low as the fetlock. This conformational abnormality–like many of the others–is congenital in nature, which means it is present at birth. This problem usually can be completely corrected with corrective trimming and shoeing, but the correction must start at an early age to be successful (by one to two months of age). This problem is frequently seen with angular limb deformities, so correction of the angular limb deformity with surgery often is necessary. Toed-in conformation leads to aberrations of the leg during flight; the leg will travel in an outward arc (paddling) during movement. The toed-in conformation leads to excessive strain on the outside or lateral aspect of the hoof and fetlock, as the horse usually lands on the outside wall of the hoof.
This flaw also is recognized when standing in front of the horse. One or both hooves point outward (opposite of toed-in). Like the previous flaw, toeing-out is a congenital problem, and can originate from the shoulder/hip or lower in the leg. Unlike the forelegs, it is normal for the hooves of the hindlegs to point out slightly. This is a result of the normal position of the stifle in the horse, which is turned out slightly. Again, like toeing-in, an angular limb deformity such as a valgus (turned outward) deformity, can exacerbate the problem. The angular deformity might require surgery; however corrective shoeing and/or trimming beginning as a young foal usually can correct the outward deviation of the hooves. In these horses, interfering of the foot and fetlock can occur, resulting in injury to the fetlock.
Carpal Valgus (Lateral Deviation Of The Carpus; Knock Knees)
Carpal valgus is one of the angular limb deformities that occurs in foals. These congenital deformities are common, but easily corrected, either with rest and trimming/shoeing or with surgery. We do not understand why they occur; theories include heredity, malposition within the uterus, and nutritional factors. Carpal valgus is when one or both carpi (knees) deviate outward when viewed from the front. If left uncorrected, this results in a great deal of stress placed on the ligaments and small bones of the carpus, especially on the medial or inner surfaces of the carpus. Although most of these deformities will correct spontaneously if mild in nature, those that are more severe or do not correct on their own require surgery within the first two months of life. After that time, the growth of the radius has greatly slowed and there is a much less chance of a successful outcome.
Carpal Varus (Medial Deviation Of The Carpus; Bow Legs)
Carpal varus is another angular limb deformity that occurs in foals and is the opposite of carpal valgus. Carpal varus is when one or both carpi (knees) deviate inward. This results is the stresses being greatest on the lateral or outer surface of the carpus. Like carpal valgus, this deformity should be corrected early to decrease the abnormal stresses placed on the small bones of the carpus and prevent injury.
Palmar Deviation Of The Knee (Calf Knee)
This conformation flaw is best seen from the side of the horse. In an animal with this flaw, if a straight line is drawn from the scapula (shoulder blade) to the hoof, the carpus will be behind the line. This fault greatly weakens the carpus and can lead to chip fractures of the radius and/or carpal bones, especially in racehorses because of the fatigue factor at the end of a race.
Dorsal Deviation Of The Knee (Over At The Knee)
Adults and foals with this flaw are best recognized from the side. A straight line from the scapula to the hoof reveals that the knee is in front of the line. The horse might appear to be buckling forward at the knee. A congenital problem in foals, it is thought to be due to “contracture” of the tendons in the back of the knee. Treatment for these foals includes splints and air casts to help straighten the leg, accompanied by treatment with oxytetracycline (an antibiotic that is thought to work by binding calcium and relaxing the muscles in the leg to allow lengthening).
Base Narrow (Stands Close)
Another conformation fault is a horse with base narrow forelegs. This condition is recognized from the front of the horse, with the distance between the horse’s forelegs being less at the hoof than at the shoulder. These horses typically have overdeveloped chests (pectoral muscles). This deformity leads to lameness problems such as ringbone (osteoarthritis of the pastern or coffin joint). The ringbone usually results because this flaw in a horse forces it to bear weight unevenly, with the horse landing on the outside of the hoof first. This uneven loading of the foot is the reason for the development of osteo-arthritis.
Base Wide (Stands Wide)
The opposite of base narrow, this flaw is recognized as the distance between the horse’s forelegs being less at the shoulder than between the hooves. Breeds with less-developed pectoral muscles more commonly are found to have this condition. As in base narrow horses, base wide horses abnormally load the joints of the lower leg, with the most stress being placed medially or on the inside of the legs. Ringbone commonly results from this conformation flaw.
Large Angulation Of The Hock (Sickle Hocks)
This conformational flaw of the hocks is best seen from the side of the horse. While in post-legged horses the hock is very straight, in sickle hocked horses the angle of the hock joint is too small and results in the cannon bone being too far underneath the horse. This conformational defect leads to stressing of the structures at the back of the hock and cannon bone, especially the plantar ligament. This ligament can be strained or injured in heavy exercise in horses with this conformation.
Exacerbated Lordosis (Swaybacked)
This conformational flaw is more common in older horses with long backs. It also is seen is some older broodmares. In longer backed horses such as American Saddlebreds, the ligaments that support the lumbar vertebrae begin to sag, thus allowing the back to sway. There is no treatment.
Brachygnathism (Parrot Mouth; Overbite)
This is a congenital conformation defect that is characterized by the lower jaw or mandible being shorter than the upper jaw. This is the most common oral conformation defect in the horse. Normal horses should have contact between the surfaces of the upper and lower teeth (arcades). A severe overbite results in difficulty chewing, and frequent dental work is required. Surgical treatment with wires to inhibit the growth of the upper arcade can be performed to help correct the deformity. However, because this condition is thought to be hereditary, many veterinarians will not perform the surgery unless the foal is neutered.
Horses with a ewe neck often are said to have their necks attached upside down. These horses have a concave neck with a depression just in front of the withers. A ewe neck appears to have more muscling on the underside of the neck. Horses with ewe necks also carry their heads higher than might be desired, and usually are athletically challenged.
The above guidelines are meant to help you evaluate conformation. There are exceptions to every rule, and some horses with poor conformation go on to be great performers. However, conformation is still one of the most reliable predictors of both athletic ability and soundness. Developing an educated “eye” for a horse and the ability to assess conformation knowledgeably are useful skills to add to your horsemanship toolbox.