Blemishes and Unsoundness of Horses
overview
INSTRUCTOR:
UNIT: Analysis of Equine Science as it Relates to the Selection of Horses
LESSON: Blemishes and Unsoundness of Horses
IMS REFERENCE: #8893-C
Topic Notes
BLEMISHES AND UNSOUNDNESSES OF HORSES
An important part of selecting and judging horses is the ability to evaluate a horse for soundness. A horse judge should be able to recognize common unsoundnesses and blemishes. A judge of horses should also be able to rate the importance of various unsoundnesses and blemishes.
A sound horse is basically normal, healthy, and free of lameness. The word unsoundness is a general term that can mean anything from a slight abnormality to a defect that makes a horse useless. A horse may be sound for one use but unsound for another. For example, a horse may be sound enough to use for breeding but unsound for riding. Technically speaking, unsoundness is any abnormal deviation in structure or function. However, horse people divide various defects and abnormalities into blemishes or unsoundnesses. A blemish is an injury or defect that may affect a horse’s value but not the horse’s ability to perform required functions. A blemish may be ugly, but it does not prevent the horse from doing its job. Wire cuts, rope burns, and other insignificant injuries or imperfections are usually in this category. Unsoundnesses are injuries or abnormalities that affect the serviceability of a horse. Many types of unsoundnesses drastically reduce a horse’s value. It is difficult to specify a defect as unsoundness or a blemish. A wounded horse may be unsound at first; but as the wound heals, it may become a blemish.
It is important for a horseperson to be able to recognize common blemishes and unsoundnesses, know their causes, and understand their effects on a horse’s serviceability. Any one or a variety of the following may cause unsoundnesses: an inherited weakness, stress, and strain far beyond the capability of normal tissue to handle, accident and injury, or nutritional deficiencies.
Unsoundnesses that definitely fall into one of the last three categories usually are not hereditary. However, horse people should be suspicious of any unsound breeding animal. Offspring probably do not inherit unsoundnesses from their parents, but an individual may inherit faulty conformation that could lead to unsoundness.
JUDGING SOUNDNESS
It is not easy to judge a horse’s soundness accurately. Inexperienced people should ask an expert for assistance. Initially, a new owner should use the horse for a trial period. During the trial period, the new owner should subject the horse to the normal conditions that the horse will experience. This allows the new owner a chance to see if the horse is sound for the intended purpose.
Most horse people can improve competence in identifying unsoundnesses and blemishes by practicing a system of inspection. First, examine the horse in its stall. If the horse kicks or paws, the stall will show signs of the activity. When the horse moves around in the stall, watch for signs of lameness, stiffness, or crampiness. Also observe the horse’s attitude in and around the stable.
The next step is to lead the horse from the stall and check the eyes for normal color and dilation. Leading the horse among obstacles immediately after coming out of a stall into bright light is a good method for testing a horse's eyesight. A horse with poor eyesight will have difficulty seeing the obstacles. Also check for lameness or stiffness while leading the horse. If a horse is lame on a foreleg, its head will nod upwards when the unsound leg hits the ground. When weight shifts from a lame hind leg to a sound hind leg, the croup will drop.
An experienced rider should work the horse and watch for signs of unsoundness. During this time, the rider can check for a breathing problem or a lameness that only shows when the horse exercises. Some lamenesses worsen with exercise while others lessen in intensity.
After the workout, make a general examination of the resting horse. The horse should stand with its weight on both forelegs. Pointing a toe and shifting weight from side to side are signs of soreness. Examine the eyes for cloudiness, and the limbs for lumps, scars, or other irregularities. Look from all angles to ensure nothing has escaped being noticed. The horse's feet should receive particular attention. Many types of unsoundness occur in the feet.
A thorough examination by a competent horseperson combined with a week's trial period should identify most unsoundnesses or blemishes.
UNSOUNDNESSES OF THE HEAD
Several forms of unsoundness can occur on or in a horse’s head. The most serious of these are those that affect the sight of the animal.
BLINDNESS – A horse can be blind in one or both eyes. A blind horse hesitates before taking a step, and usually moves its ears around more than does a normal horse. To check for blindness, wave a hand in front of the horse’s eye. A blind horse will not react, but a normal horse will jerk its head.
MOON BLINDNESS (PERIODIC OPTHALMIA) – This condition is characterized by cloudiness and inflammation of the eye. The horse may go through a series of recoveries and relapses that eventually end in blindness. A deficiency of riboflavin (Vitamin B-2) is a major cause of moon blindness. Moon blindness also can be caused by various bacterial or parasitic infections. If the horseperson catches and treats the condition in the early stages, recovery is possible.
NIGHT BLINDNESS – A horse with night blindness has poor vision during twilight hours. In strange surroundings, the horse may stumble over or bump into things during darkness. Night blindness is usually caused by a deficiency of vitamin A.
OVERSHOT AND UNDERSHOT JAW – The overshot jaw (parrot mouth) occurs when the upper incisors extend beyond the lower incisors. The opposite condition is the undershot jaw (monkey mouth). Both conditions are hereditary and result in a horse having difficulty eating and grazing.
POLL EVIL – Poll evil is an inflamed swelling resulting from a bruise or irritation in the poll region. The swelling usually contains pus. Healing is often very slow and difficult; therefore, a veterinarian should treat the injury. Even when the condition is apparently under control, it may break out again. Bruises to the poll may occur from someone hitting the horse between the ears, or from the horse bumping its head on the roof of a trailer or stall.
WOBBLER – This term describes several conditions that affect a horse’s coordination by affecting the spinal cord. The symptoms may occur anytime from birth until the horse is three or four years old. In the early stages it is difficult to recognize a wobbler. The condition begins with incoordination of both hind legs that worsens over time. Signs of incoordination include dragging the hind toes, and errors in the rate, range, force, and direction of movement. The symptoms may become so severe that the horse falls if it tries to change directions quickly. Wobbling is a serious unsoundness because the condition will not improve. Wobblers are unsafe to ride. The condition may be hereditary, so wobblers should be avoided in breeding programs.
UNSOUNDNESSES OF THE WITHERS AND SHOULDERS
Unsoundnesses occur less frequently in the withers and shoulders than in the feet and legs. However, the following two conditions are very detrimental to affected animals.
FISTULOUS WITHERS – Fistulous withers is an inflamed swelling of the withers. Bruising of the withers commonly causes the condition. In the past, pressure from a horse collar on a harness was the most likely cause of bruises on a horse's withers. Today, the condition most frequently is a result of a poorly fitted saddle.
Except for location, fistula and poll evil are similar conditions. Therefore, treatment of fistulous withers should be the same as for poll evil. A veterinarian should remove the dead tissue and allow the swelling to drain. Healing may be slow, and the horseperson must take precautions to prevent the condition from recurring.
SWEENEY – Horses with sweeney experience atrophy or a decrease in the size of a muscle or group of muscles. The term “Sweeney” actually applies to atrophied muscles anywhere on the body, but most horse people confine its usage to the shoulder muscles. Degeneration of the muscles result either from lack of use or loss of nerve supply. There is no available treatment for sweeney, but sometimes the nerves will regenerate. If not, some horse traders inject irritants into the area. This causes a buildup of scar tissue, which fills in the depressed area.
LEG UNSOUNDNESSES (FORELEGS)
BUCKED SHINS – A bucked shin is a painful inflammation of the front surface of the bone covering of the cannon bone. Racing 2-year-olds and 3-year-olds and other young horses that are in vigorous training sometimes causes this temporary unsoundness. Shins are usually bucked during the first few weeks of training and before the animal is physically fit. The horse usually recovers after 30 to 60 days of rest.
BOWED TENDONS – Horses develop bowed tendons as a result of stress on the flexor tendons behind the cannon bones. Long and weak pasterns, long toes, improper shoeing, overexertion, fatigue, or weak tendons can contribute to the development of this condition.
Bowed tendons usually occur in the forelegs but occasionally occur on a hind leg. The condition appears as a thickened enlargement on the affected tendon.
Horses suffering from bowed tendons usually recover with rest. However, only a few of these horses are sound for hard work after they recover.
They usually bow the tendons again during hard work.
RING BONE – Ring bone is a bony growth on either or both sides of the pastern. Ring bone can also extend all the way around the pastern. Ring bone occurs most often on the forefeet, resulting in lameness and stiff ankles. Causes of the condition include excess strain on the ligaments, injury from a direct blow, concussion from constant work on hard surfaces, hard work over time, straight pasterns, or toe-in or toe-out conditions. Ring bone is not as common as is side bones.
If the ring bone occurs on the upper part of the pastern and does not affect the joint surface, it usually will not result in unsoundness. If the condition occurs on the lower part of the pastern, the horse will travel on its heels. If it affects the joint surface, then the horse will be unsound. Treatment consists of application of cold-water bandages for temporary relief.
SHOE BOIL OR CAPPED ELBOW – Shoe boil (capped elbow) is a soft, flabby swelling on the point of the elbow. The two most common causes are injury from a long heel or heel calk of a front shoe and injury from contact with the surface the horse is lying on.
Treatment of shoe boil includes daily application of iodine to the affected area. A boot or roll is also helpful in treatment of shoe boil. The roll straps around the pastern and prevents the heel of the foot or shoe from pressing on the elbow while the horse is lying down.
SPLINTS – Splints are abnormal or new bony growths usually on the inside of the upper part of the front cannons. Splints most often cause lameness only in the early stages. Causes of splints include excess strain on the ligaments of young horses from overwork, hard stops, fast turns, jumping on hard ground or galloping on hard surfaces. The strain on the ligaments results in blood rushing to the area stimulating new bone growth.
Horses with bench knees, toe-in, toe-out, or straight pasterns tend to develop splints. If a splint is the result of leg conformation faults or if it interferes with ligament or tendon action, it is an unsoundness. If a splint does not cause lameness, it is a blemish. Young horses should wear splint boots while in training to help prevent splints from developing.
WIND PUFF – Wind puffs (windgalls or puffs) are puffy swellings or fluid sacs occurring on either side of tendons above the fetlock on front or hind feet. They result from too hard or too fast work on a hard surface.
Sometimes wind puffs result simply from hard work. Wind puffs often plague old horses. Application of cold packs and liniment will reduce the size of a wind puff, but the puff will reappear when the horse exercises. Wind puffs usually are not serious, and no permanent benefit results from treatment.
OSSELETS – Osselets are primarily an affliction of young horses. They are a result of strain or pressure during training that is greater than the immature bone structure can withstand. Osselets are inflammatory conditions or swelling around a fetlock joint. The horse exhibits a short choppy stride with noticeable pain when the fetlock is flexed. Rest may be helpful in the treatment of osselets. However, an osselet usually affects the horse for several years because it is an arthritic condition.
POPPED KNEES – Horses with popped knees exhibit inflammation and swelling with fluid on the knees. Popped knees usually develop suddenly. Some causes are strains to the ligaments holding the kneecap in place (as occurs during hard training for racing) or blows to the knees. Poor knee conformation, such as bench knees or calf knees, can also cause popped knees. Horses suffering from severe popped knees rarely become sound enough to resume hard work.
SESAMOIDITIS – Inflammation of the sesamoid bones at the back of the fetlock joint characterizes this condition. A horse suffering from sesamoiditis will favor the fetlock because of pain. The major cause of sesamoiditis is unusual strain to the fetlock area, especially in racing or jumping horses. In chronic cases, there may be new bone growth in the sesamoid area.