Description of the Sport

The American Saddlebred, Morgan, Hackney Pony, National Show Horse, and Arabian (see Chapter 123) show horses are described as trotting breeds with collection. Lameness in disciplines such as dressage, road horses, and road ponies is similar. The American Saddlebred and National Show Horse have five gaits: walk, trot, canter, slow gait, and rack. The slow gait and rack are manmade gaits. These horses also perform in three gaited classes (walk, trot, and canter), fine harness classes, pleasure driving, pleasure-gaited classes, and equitation. Morgan and Arabian horses are shown similarly, but without the slow gait or rack. Hackney ponies are shown in harness, pleasure driving, and road pony classes. Show classes are further divided for professional, amateur, and juvenile riders. Equitation, hunt seat, Western, and numerous young horse and in-hand halter classes are available.

In road horse classes, Standardbreds, Morgans, American Saddlebreds, or Standardbred-cross horses are shown at the walk, trot, and road gait pulling a bike similar to a sulky used for Standardbred racehorses. These horses usually are more animated in gait than Standardbred racehorses and go both ways around the ring when performing. The road gait is a high-speed performance gait.

To understand lameness in a gaited show horse, the veterinarian must first understand the difference in locomotion between running and gaited horse disciplines. Concussion (impact) is a part of every gait. How a horse distributes concussion is related directly to athletic ability and the longevity of the horse’s career. Better equine athletes are more efficient in the distribution of concussion through the limbs and body. A superior equine athlete appears capable of using energy of concussion efficiently and distributing it for dispersion and recovery. Normally kinetic or stored energy from proper distribution of concussion causes recoil of the tissues receiving the energy of concussion. Tissue injury results in an inability to disperse concussive energy properly. Maintaining healthy hoof wall, bone, cartilage, tendons, ligaments, and muscles in a good conditioning and gait management program is essential. A veterinarian must be familiar with the gaits, because gait analysis is an important part of evaluating poor performance and subtle lameness. Many times a veterinarian may be dealing with a gait abnormality caused by the bit, saddle fit, or faulty shoeing rather than lameness.

Gaits of show horses are complex and must be synchronous to maintain distribution of concussion. Synchrony must be achieved in up to five gaits and is altered by the different gait specifications. Unlike most other horses the normal load distribution between forelimbs and hindlimbs in a show horse is about 35% and 65%, respectively (see Chapter 2). A show horse does not have to perform at racing speed. Synchrony of concussion and weight distribution are totally different compared with many sports horses, and because much concussion is dispersed through the hindlimbs, hindlimb lameness is more prevalent. In some other sports horses the head and neck are raised and lowered with the stride, a movement that assists in balance, energy distribution, and propulsion. A show horse, like a dressage horse, maintains a fixed and flexed head and neck carriage. This further shifts the balance and energy of concussion to the hindlimbs.

Show horses carry more body weight for a fleshier look than the greyhound-like racing counterparts. Riders of show horses, as a rule, also are heavier than racing jockeys.

Longevity of show horses compared with racehorses is related directly to speed of performance, which is dramatically less. Racehorses must change energy distribution at high speed quickly, potentially leading to catastrophic breakdown, but such actions and injuries in show horses are rare. A show horse often can remain competitive into the late teens and early twenties, but chronic wear and tear may result in lameness.

Although show horses do not perform at speed, high head carriage and high limb action and motion are strenuous. Show horses perform numerous gait changes and transitions going in both directions of the ring, and for a high-level (stake class) five-gaited class to last from 30 to 40 minutes is not unusual.

Because five-gaited movements and transitions are complex and arduous, compensatory lameness is common. A methodical approach to lameness diagnosis must be used to differentiate primary and compensatory lameness. A superior show horse distinctly separates its different gait movements, raising each carpus above the horizontal, with a high hock action. The horse drives off its hindlimbs with a flexed high head and neck carriage. Responsiveness to the bit, with an alert expression and attitude, and forward placement of the ears are desirable. Just as racehorses are bred for speed, show horses are bred for animated motion.

American Saddlebred

The American Saddlebred has a long history and aptitude for different gaits and is derived from many different lineages. The breed was developed in a young country where the best horses could be bred to the best. The American Saddlebred was developed as a horse of usefulness and beauty that could work in the field, pull a buggy or carriage, and have gaits that were smooth for travel under saddle.

The ability of the American Saddlebred to perform lateral gaits (slow gait and rack) came from the Narragansett pacers, which were among the earliest known easy-riding pacers. The Narragansett pacers were derived from French Canadian pacers of Arabian and Andalusian descent that were bred 100 to 200 years before the American Revolutionary War and had a comfortable saddle gait. Early settlers brought these horses, known as saddlers, to Kentucky. During the late 1830s and 1840s, many of these easy-riding saddlers were bred to the Thoroughbred foundation sires Denmark and Montrose. These crossbreeds were then bred to horses of trotting blood, from which the Standardbred breed was developed. Offspring of these crosses became favorite mounts of cavalry during the Civil War because they had an easy gait, versatility, and an ability to withstand the pressures of war. On April 7, 1891, the American Saddlebred Breeders Association was founded in Louisville, Kentucky, and became the first all-American breed registry. In recent years the American Saddlebred has gained popularity in South Africa and has been crossed with European Warmblood and carriage bloodlines (e.g., Dutch Carriage Horse). During the 1980s, the National Show Horse was derived from American Saddlebred and Arabian lineage.

The American Saddlebred ranges in height from 152 to 178 cm (15 to 17.2 hands; average 160 cm [15.3 hands]) and varies in weight from 455 to 545 kg. Colors include chestnut, bay, black, gray, golden (palomino), and spotted (chestnut, black, or bay mixed with white). As described in Modern Breeds of Livestock¹:

[The] American Saddlebred has a strikingly long neck and considerable arch to the neck. The American Saddlebred is refined in appearance; has long, sloping pasterns that give spring to the stride; has a long, level croup; is strong and short-coupled; and has a back with high, well-defined withers above the level of the hips. The American Saddlebred is famous for refinement, smoothness, proportion, and a beautiful and handsome presentation and projects an alert, curious, expressive personality.

There are shows for American Saddlebreds throughout the United States and South Africa. The World Championship Horse Show is held each year in Louisville, Kentucky. Shows are run under the guidelines of USA Equestrian, which establishes rules, regulations, and drug-testing procedures. A veterinarian must be aware of current drug and medication rules, and failure to do so may result in fines and penalties to the horse, owner, and trainer.

Saddlebred Gaits

The five gaits of the American Saddlebred and other gaited horses are as follows²:

Lameness Examination

The history of lameness and poor performance must be discussed with the trainer and rider to seek their perception. This should include noting any problems with the bridle and the way a horse pulls on the bit and bridle. Show horses with hindlimb lameness often fight the bit and try to lower the head, an observation known as diving in the bit. Horses that become one-sided in the bit may have contralateral hindlimb or ipsilateral forelimb lameness. Faulty bit and bridle placement may cause gait abnormalities, particularly of the hindlimbs. Keeping the head up and fixed in position in a horse that dives in the bit is difficult. A horse with forelimb lameness is more likely to raise up out of the bridle. A horse cannot produce a gait properly or do proper gait transitions when being pushed into an uncomfortable bridle or if the rider is using the bit improperly. It is important to determine if the rider is using the bit to balance the horse or himself or herself. A rider using the bit poorly can induce a gait abnormality. Bit and bridle responsiveness is often a wild card that must be played during examination of a show horse for gait abnormalities and lameness.

Problems with a particular gait may indicate the source of lameness. Back pain is seen in horses that have difficulty in the canter, a condition known as being broke in the middle. This occurs with asynchronous movement of the forelimbs and hindlimbs. Broke in the middle also can be caused by stifle pain that causes a reduction in the cranial phase of the stride. Most commonly, however, broke in the middle is caused by stringhalt. Stringhalt prevents the limb from moving forward at a time when the forelimbs are required to go faster, causing a mismatch in synchronization between the forelimbs and hindlimbs. Distal hock joint pain and back pain can cause a hitching motion of the hindlimbs, jerking the lame limb caudally and leaving the hocks behind the motion.

Examination first begins in a stall before the horse is worked. Careful palpation with emphasis on the tendons, ligaments, joint capsules, and bulbs of the heels should be performed. Palpation of the back and gluteal muscles before working is important, because the horse can warm out of soreness in these areas. Digital pulse amplitudes should be assessed.

The horse should be evaluated during movement under tack. Harness horses, road horses, and ponies should be examined while working with and without the overcheck (checked up and without the check). Five- and three-gaited horses should be examined performing each gait going in both directions. Often horses are lame only while going in one direction or only in the turns. Horses with lameness from the hock distally are often worse with the lame limb on the inside, whereas those with pain located more proximally are lame with the lame limb on the outside of the turn. Forelimb lameness is usually worse with the affected limb on the inside.

In most show horses flexion tests can be performed with a rider or in harness. The horse’s temperament may make this difficult, but I find that the horse being ridden or jogged in a cart after flexion is helpful.

Diagnostic Analgesia

Diagnostic analgesia in show horses is similar to that described for other sports horses. I start distally and work proximally.