Developmental Orthopedic Disease (DOD) is an umbrella term used to categorize a variety of acquired musculoskeletal disorders commonly seen in young growing horses. Often interrelated, these DOD conditions require assessment and management through careful control of exercise and nutrition. Early detection and diagnosis of these conditions usually result in a more rapid and satisfactory response to treatment and changes in management.
Acquired flexural deformities of the fetlock joint (joints) may occur from birth to 18 months of age. Mild cases may exhibit upright fetlocks while moderate and severe forms show dorsiflexion progressing to 'knuckling over.' Treatments will vary depending on the severity of the deformity. Diet evaluation is critical to ensure the essential nutrients necessary for proper growth and development are supplied in the appropriate proportions. Along with a balanced diet, non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain will be given in conjunction with prescribed treatments such as physical therapy, corrective shoeing, splints or surgery.
Club feet, involving increased angulation and shortening of the dorsal hoof wall and elongation of the heels ,usually develop at 2-6 months of age by acquired flexural deformity of the distal interphalangeal (coffin) joint. This condition often starts with a traumatic front heel pain following dry hard conditions, which suddenly causes the foal to walk on its toes to prevent the heel from touching the ground (so-called 'ballerina' syndrome). If the club foot is recognized immediately and proper treatment administered, correction usually occurs quickly and the foal's heels will return to weight bearing. If the condition is allowed to persist, a true club foot or feet may result, with the heels lengthening to reach the ground. In this situation, aggressive farrier work and veterinary care are needed to develop a plan to best shorten the heel, reduce inflammation and pain along with controlled exercise to encourage heel weight bearing. In extreme cases, or cases that do not respond to initial treatment, surgical procedures are usually necessary.
The key to successful resolution of acquired flexural deformities is early diagnosis, nutritional diet evaluation to ensure appropriate intakes of protein, vitamins, minerals and trace elements and supportive veterinary and farrier care.
Valgus deformities, abnormally turned, of the horse's carpus (knee) and tarsus (hock) and varus deformities, pointing away from the midline, of the fetlock joints (metacarpo/metatarsophalangeal) are the most commonly diagnosed acquired angular limb deformities in young horses. Deformities arising from the diaphysis of the metacarpus and metatarsus, as well as rotational deformities, have also been reported. Radiographs will determine the diagnosis, congenital or acquired deformities and signs of Degenerative Joint Disease in long-standing cases.
Many cases of acquired angular limb deformities respond well to a more conservative treatment program, farrier work and controlled exercise on level surfaces. During this stage of a young horse's life, casts and splints are seldom successful and increase the risk of pressure sore production. When conservative treatments are unsuccessful or the case is severe enough, surgical intervention may be necessary. This type of treatment must be attempted before the involved growth plate closes, i.e. before 6 weeks of age for the fetlock joints and before 4 to 6 months of age for the knee and hock.
Physitis occurs in the distal metacarpus and metatarsus, distal radius and distal tarsus with peak incidences between 4 and 8 months of age and 1 to 2 years of age. Physitis is typically diagnosed based on grossly enlarged, warm and painful to the touch physis or physes accompanied by varying degrees of lameness. Radiographs that present widening of the cartilage zone, excessive wavelike bends, curves or elevations of the growth plate(s) and signs of sclerosis and flair are used to further confirm physitis diagnosis in the affected area. When physitis is recognized early restricted exercise and, when indicated, non-steroidal anti-inflammatory medication is usually successful in remedying the situation. Cases that have gone undiagnosed for an extended period of time and especially those that have developed into angular limb deformities are more difficult to correct. Bilaterally symmetrical growth plate enlargement and prominence is frequently seen in some young horses or in response to a growth spurt and is generally not a cause for concern.
Osteochondrosis and Osteochondritis Dissecans are associated with focal failures of the endochondral ossification (within cartilage bone formation) occurring in both the metaphyseal growth plate and the articular/epiphyseal cartilage complex. Osteochondrosis commonly describes joint surface flattening and ulceration while Osteochondritis Dissecans (OCD) is normally reserved for joint lesions with fragmentation. The cause or origin of these conditions is clearly multi-factorial and is still not fully understood. Any joint may be involved and varying degrees of lameness and joint effusion are typically clinical symptoms and radiographs will be used to confirm the diagnosis.
Conservative treatment, with reduced exercise, nutritional diet evaluation and modification including vitamin, mineral and trace element supplementation and non-steroidal anti-inflammatory medication is often successful in allowing for functional repair, following early diagnosis. Surgical intervention followed by adequate periods of rest and recuperation, may be helpful for cases with large, extensive and fragmenting lesions and those cases that don't respond to initial more conservative treatments. If the condition is not diagnosed early and conservative treatment implemented, degenerative joint disease may follow and can jeopardize chances for an athletic future.
Cystic lesions occur in the subchondral bones of young horses at any site but are most commonly seen in the stifle joint. The cause of subchondral bone cysts is believed to be similar to osteochondrosis with varying degrees of lameness and joint effusion being presented clinically. Radiographs will confirm joint lesions. Many cases respond to conservative treatment similar to that used in osteochondrosis treatments while others may require arthroscopic surgery.
Degenerative Joint Disease (DJD) can occur in young, growing horses, most commonly involving the fetlock and hock joints. This is now believed to be a form of DOD since many horses with DJD show symptoms of osteochondrosis. Juvenile osteoarthritis presents itself with lameness and joint effusion and is confirmed with radiographic examinations. Degenerative Joint Disease cannot be cured, only controlled by restricted exercise, non-steroidal anti-inflammatory and chondroprotective medication and dietary evaluation and adjustment (while supplementing vitamins, minerals and trace elements).
Since DODs are multi-factorial in origin, involving congenital deformity, genetic predisposition, trauma and concussion, rapid growth rates, nutrition and endocrine factors, it is important to attempt to reduce the incidence of DOD. It is recommended to avoid breeding horses with genetic predispositions to DOD's and accelerated growth rates, and to carefully manage the nutritional programs for pregnant broodmares, weanling and yearlings to achieve steady, sustained and appropriate growth rates. Utilizing commercially prepared rations formulated for breeding and growing horses, such as Gro 'n Win®, Gro 'n Win® Alfa and Buckeye® Nutrition Growth feed will provide the correct quantities and proportions of amino acids, energy, vitamins, minerals and trace elements essential for proper growth and development. Access to ad libitum safe, natural exercise should be allowed but not forced and complete stall rest, unless necessary due to surgery, is not recommended as exercise is believed to be beneficial for healthy joint surfaces.
Gro 'n Win® is the best formula for proper growth and development. Gro 'n Win® is a safe, low-starch and sugar, low-glycemic formula that provides all the essential nutrients not adequately supplied in forage-based diets. The high-antioxidant content is proven to support your horse's immune system, while the high-quality amino acids provide the essential building blocks necessary to support growth and development in your breeding and growing horses.
