Horse Ailments

Horses can be affected by a number of ailments:

Myositis is an inflammation of the muscle. The inflammation can originate from trauma, bacteria, and viruses or even through the administration of irritating substances through injections. The inflammatory response within muscle tissue is a series of sequenced events that occurs after any insult to the muscle. The injured muscle tissues release histamine, serotonin, and kinins. All of these result in a vasodilatation (dilated blood vessels) and an increased permeability within the walls of the blood vessels. The tissue swells and this is referred to as edema. Pain is also brought forth within the area due to the presence of toxic substances on the sensory nerve endings.

Exertional Rhabdomyolysis, commonly known by trainers as Monday Morning Sickness, also as azoturia, is a muscular disorder. The condition can range from mild stiffness of the musculature to actual cramping and recumbency (lying down for relief). The initial stiffness usually occurs in the neck muscles and over the gluteal areas. These animals will sweat excessively and have elevated cardiovascular and respiratory rates in addition to a slight increase in body temperature. When the muscles are palpated (feeling for pain), there is pain with only minor finger pressure. The muscles feel tense and stiff, especially along the longissimus dorsi and gluteal regions. Another classic symptom of these horses is myoglobinuria, which horsemen refer to as coffee-coloured urine.

Neurological Disorders

Three of the most common neurological disorders affecting the musculature are equine herpesvirus myeloencephalopathy, hyperkalemic periodic paralysis and equine protozoal myeloencephalitis. These are not the only neurological disorders of the horse but these are once most commonly seen affecting the musculature.

Equine Herpesvirus Myeloencephalopathy - Whenever there is a large concentration of horses such as at the racetrack, breeding farm or boarding stable, there is a high incidence of viral infections. These animals develop a fever and there is usually evidence of a mild respiratory tract disorder. This may be manifested merely as a cough or a slight nasal discharge. Initially, the animal may show signs of a slight lameness or abnormal gait. As the virus progresses, the animal may appear stiff and show signs of weakness and loss of coordination within the limbs.

Hyperkalemic Periodic Paralysis (HYPP) - This disorder involves the peripheral nerves and musculature. It is a familial disorder that affects pure and part quarter horses in North America. HYPP is similar to hyperkalemic periodic paralysis in people in that these animals undergo episodes of muscular weakness. It is more common in colts than in fillies, and it usually affects horses that are less than 4 years old. These animals appear more than healthy between episodes of weakness. Any stressful stimuli such as exercise, high environmental temperature and transport may hasten a clinical manifestation of this disorder. However, the condition is unpredictable and may occur randomly. Initially, the animal will appear still and will have a drooping of the third eyelid. The horse will begin to sweat, and muscle fasciculation will occur. As the episode progresses, these animals become recumbent and the muscles develop flaccidity. The horse's respiratory and heart rates are usually elevated. The animal will be alert and able to respond to noise and visual stimuli. These episodes usually last between 15 to 20 minutes.

Equine Protozoal Myeloencephalitis - EPM is a debilitating disease that results in asymmetric incoordination, weakness, muscle spasm, and may potentially be fatal. This disorder is causes by the protozoan Sarcocytis falcatula. This organism can affect horses of all ages but is more commonly diagnosed in horses less than four years old.

Lower limb lameness affects the musculature of the horse's back. Upon injuring the foot or lower limb, the animal will compensate for the injury consequently putting added/different stress on subsequent upper leg and back muscles. Therefore, it is only logical to use Ultrasound Therapy to alleviate any secondary soreness within these muscles. A normal therapy regimen should be followed at least once per day with more aggressive plans initiated if the lameness is more severe.

Forelimb Disorders

Common Carpal (knee) Disorders - The equine athlete places a tremendous amount of concussive forces upon the knee during heavy exercise. This results in carpitis, carpal tunnel syndrome, and degenerative joint disease within the joints.

Carpitis - an overexertion of the carpus, such as that when a cross country eventer clears a jump and the landing side is sloped away from the jump, results in carpitis. Simply, carpitis is an inflammation within the tissues of the knee.

Carpal tunnel syndrome results from an inflammation and pressure within the carpal canal usually caused by tendonitis of the flexor tendons, inflammation of the superior check ligament or a fracture in this area. As these tissues swell, pressure is applied upon the neurovascular supply to this area which results in a compensated blood flow to the tissues farthest away from the point of origin. This pressure also results in pain to the affected limb.

Degenerative joint disease - DJD of the carpus can be mild in nature to severely debilitating. Repetitive concussive trauma to the joints within the knee results in a thickening and fibrosis of the synovial membrane and joint capsule, a breakdown of the cartilage and subsequent formation of osteophytes on the bony structures. These pathological changes result in a decrease in the ability of the joint to flex through normal range of motion.

"Bucked Shin" (Dorsal metacarpal disease) - Horsemen traditionally refer to the slight inflammation and swelling on the dorsal (upper back) surface of the third metacarpal bone as "bucked shins." At the first indication of swelling or pain, an accurate diagnosis should be made. If caught in the early stages, systemic anti-inflammatory and an intense physical therapy regimen should be undertaken. The goal of a physical therapy regimen is to reduce inflammation and pain while allowing the bone to remodel subsequent to the workload. Initially, cold therapy is indicated until the swelling and inflammatory process is stopped. After this is accomplished, alternate cold and therapeutic heat is indicated.

Desmitis - Any inflammation within the suspensory ligament is referred to as being desmitis. Usually there is a slight swelling within this structure and often a mild lameness. When palpated digitally, there is evidence of pain. When this injury is acute, cold therapy is the first measure to be taken. After 24 hours, alternating cold with Ultrasound Therapy will speed the healing process. Desmitis of the inferior check ligament is a common disorder in trotters and pacers. Stress on this ligament occurs when an animal is shod with a long toe and low heal to obtain a longer stride. This coupled with an imbalanced situation towards the medial side of the foot results in a significant strain to this ligament.

Tendonitis - Tendonitis is simply any inflammation within the tendon.

Tendosynovitis - Tendosynovitis is any inflammation within the tendon sheath. Horsemen refer to any swelling or inflammation within the flexor tendons on the palmar aspect of the metacarpals as a "bowed tendon". Depending on their location, they are further classified as "high", "middle" and "low" bows. All of these pathological changes are the result of stress, strain and concussive force upon these anatomical structures.

Ringbone is new bone growth that originates and forms on the dorsal, dorsolateral, and dorsomedial surfaces of the first and second phalanges and the extensor process of the third phalanx. There are four forms of ringbone: high, low, periarticular and articular.

Osteochondrosis of the fetlock arises from a genetic predisposition, rapid growth rates and nutritional imbalances. It is simply cartilage that fails to develop into healthy solid bony tissue. These areas are therefore weak and easily injured from the trauma of normal athletic activity. There are two basic categories of osteochondrosis within the fetlock. Concussive trauma from athletic exercise results in these weakened areas to form subchondral bone cysts whereas shearing forces applied to these weakened areas result in a flap of cartilage within the joint itself, which is referred to as osteochondritis dissecans lesion or OCD.

Osselets are a traumatic arthritis of the metacarpophalangeal joint. This results from a capsulitis and synovitis at the dorsal aspect of the metacarpophalangeal joint. When these cases become chronic, there is ossification that will develop within this capsule. This condition results from athletic competition and training where there is a constant concussive trauma to the fetlock joint. When this disorder is in the acute stage, it is referred to as "green osselets." There is swelling and pain along the dorsal aspect of the fetlock. When the condition progresses, there will be a thickening within the joint capsule. Aggressive physical therapy techniques coupled with systemic treatment, corrective shoeing and a change in the training program will greatly aid in the management of this disorder.

Sesamoiditis - Constant repetitive concussive forces result in a stress and strain to the proximial sesamoid bones and their associated ligamentous structures. This in turn causes an inflammatory reaction within these tissues termed sesamoiditis. These animals exhibit a mild lameness and exhibit pain upon touch. Rest and corrective shoeing help alleviate this condition but they will recover faster with an aggressive physical therapy program. In the acute stage cold therapy is very beneficial for the first 24 to 48 hours. After this time, alternating cold and Ultrasound Therapy will speed the healing process. As well, after recovery, pre-exercise warming of these tissues helps prevent reinjury.

Hindlimb Disorders

Bone spavin - This is a condition of osteochondrosis and osteitis of the tarsal bones of the hock. This is a degenerative condition that can eventually lead to an ankylosis, the fusion of bones at a joint, or fusion of the joints within the hock. This disorder is quite common in standardbreds and the first indication that the problem exists is the animal will exercise "on the line". This means that the animal is not pacing or trotting straight in the cart but that the hindquarters are moving towards the shaft of the cart either towards or away from the affected side.

Curbs Conformational challenges, disordered animals, predispose the animal to curbs. A "curb" is a sprain to the tarsal plantar ligament. The clinical sign of this disorder is a visual swelling on the plantar aspect of the hock distal to the point of the hock. When palpated, feeling for pain sensitive areas, there is usually heat and swelling in these soft tissues. The goal of the physical therapy aspect of treating this disorder is to reduce the swelling, alleviate pain, and restore the tissues to a normal state. Unfortunately, once this injury occurs, it often becomes chronic and requires therapy on a daily basis.

Cunean bursitis - An inflammatory reaction within the cunean bursa, cunean tendon and all of the associated soft tissue structures around the distal intertarsal and tarsometatarsal joints. The most common cause of this disorder is improper training. Asking the animal to perform too hard, too soon is often coupled with improper shoeing and a conformationally challenged horse. An aggressive physical therapy program using Ultrasound Therapy together with a reconditioning period in the training program will allow an almost complete recovery from this injury.

Capped hock - A capped hock is a visible subcutaneous, lying under the skin, swelling at the point of the hock. It is a hydroma , cystic swelling, or a traumatic bursitis that usually results from an animal kicking either in the stall or trailer. The goal of Ultrasound Therapy to these cases is to reduce the swelling within the tissues. Since most of these animals are "kickers," care must be taken in introducing these animals to this therapy program.

Osteochondrosis - The tarsal bones is a failure of the developing cartilage cells to form good solid bone. These areas of inadequate bone development cannot withstand the stresses placed upon them as sold bony tissue normally would. This results in pain and inflammation within the joint. Conservative treatment of these lesions includes systemic and intraarticular therapy coupled with an aggressive physical therapy program. In severe cases, arthroscopic surgery is required to help resolve this severe lameness issue. Ultrasound Therapy will allow the joint fluid to properly lubricate, reduce the swelling and alleviate the pain within the joint. If surgery is required to resolve the issue, several days after surgery Ultrasound Therapy can be used to speed the recovery.

Temporomandibular Joint Function (TMJ) - Issues are unique because we use their mouth and jaw as a communication point. If the TMJ is dysfunctional or painful and the bit is moved to the left or right then the jaw receives lateral pressure to move in that direction. Painful reactions to the bit in the TMJ may be responsible for the horse resisting directional cues. The hesitation involved can be the difference between a first place finish and a less desirable outcome. The term "collection" is found frequently in the horse industry and is used to describe a very specific posture in the horse. Proper posture is strongly and uniquely related to the TM joint in both humans and horses. Substantial evidence and understanding of this posture indicates that it is primary to many of the movements that are actively sought by equine competitors. The ease with which a horse can be collected may rely heavily on correct TM joint function.