VETERINARY TOPICS GREGORY BEROZA, D.V.M. Treating OCD and bone cysts Diet plays a large role in minimizing developmental orthopedic diseases

HORSES OF all ages are prone to the lubricating joint fluid. There is turing cartilage cells into abnormally to be clinically relevant. Therefore, results regarding a return to racing having hidden damage within their also the resulting loss of normal retained and thickened cartilage. The radiographically evident bone cysts soundness, many varied treatments joints which can affect their bone/cartilage mechanical support, thickened cartilage may die,develop should always be linked to clinical historically have been used. Admin- soundness. OCD lesions (osteo- initiating an inflamed joint and early cracks, produce fragments of com- signs prior to therapy. istering local joint medications com- chondritis dissecans:bone cysts and clinical arthritis. bined bone and cartilage that detach Surgery is a treatment option. bined with rest or controlled exercise osteochondral fragments) are mostly OCD cyst-like erosions of bone into the joint, and/or develop into However, with conservative care has been beneficial. found in young horses such as year- are single circular areas of decreased bone cysts. The causes are variable and/or controlled exercise, bone lings. However, they also can first bone density, seen on radiographs, and consist of: a loss of blood sup- cysts can heal or they may subside Diet and OCD be discovered in older horses. and found within the ends of bones, ply due to local trauma; congenital in time. Surgery to remove bone- A relationship may exist between Sometimes OCD lesions are not contained within joints. These weak- deformities; excessive biomechan- cartilage fragments and to elimi- too-rapid foal growth rates,too high noticeable, having no clinical ened cystic areas of bone, which ical force; and nutritional abnormal- nate bone cysts may be considered a nutritional level, and too low a effects even during initial race train- can create joint abnormalities, may ities, such as copper deficiency, that in horses without clinical signs if mineral content, specifically cal- ing,but create soundness issues later lie just below the surface of what lead to connective tissue fragility. they are intended to be sold. cium, phosphorus, and copper. in a horse’s career. They can cause appears to be normal articular Zinc, cadmium, and other min- increased joint swelling,or they can cartilage, or they may involve de- erals in competitively too high lev- occur in otherwise normal-appear- terioration and/or loss of what should els are considered toxic causes of ing joints. otherwise be normal joint cartilage. OCD. The best method of diagnos- There may be increased heat as- Technically,OCD also includes frac- ing mineral deficiencies and toxi- sociated with affected joints, and tured composite pieces of bone and cities is through ration evaluation. the normal lubricating viscosity of cartilaginous joint fragments that To a lesser degree, blood, hair, and the joint fluid may decrease. There do not have to be associated with a hoof analysis also can be helpful. may be soreness or unsoundness of bone cyst. Excessive energy intake due to high levels of carbohydrate (grain) varying degrees. Clinical problems Navicular bone OCD cyst are due to deterioration of the joint’s feeding can cause too-rapid growth otherwise normal cartilage that re- Diagnosing joint disease due to and increased body fat, increased sults in both the release of irritat- OCD bone cysts or osteo- blood glucose and insulin, and in- ing pieces of cartilage and/or bone cartilaginous fragments can be chal- creased incidence of OCD. fragments (even microscopic) into lenging. Clinical signs such as Both sexes are equally affected Stifle OCD cyst on femur excessive joint heat and swelling and there is disagreement regarding The joints most commonly af- associated with unsoundness in se- the effects of exercise and the inci- fected by bone cysts include the lect joints are helpful, but are often dence of OCD. Some OCD lesions hock, stifle, fetlock, elbow, and inconsistent in presentation. Block- that have been identified in foals shoulder. Although cysts may occur ing suspected joints with local anes- within one to three months of age simultaneously in identical joints thetic can be helpful. Radiographs have resolved by five to eight months of both right and left legs, it is un- are useful in determining cause, of age. After eight months of age, common for them to affect more once an affected joint has been iden- however,most damage is permanent. There are considerations for op- Radiograph stifle OCD on femur than one type of joint in different tified. Diagnostic nuclear scinti- locations at the same time. graphic imaging can be especially timal feeding of mares and foals as- OCD results from metabolic de- While most bone cysts form be- beneficial. However,such diagnos- sociated with six stages of pregnancy, velopmental bone diseases which fore horses are six months of age, tics may miss the identification of birthing and foal maturity: start as a failure or interruption of they are often diagnosed at a later a quiet subclinical bone cyst. 1) The first five to seven months normal bone maturation from fetal age. Even though evident radi- Due to many types of OCD dis- of pregnancy require only minimal prebone cartilage. The disease is ographically,some bone cysts either eases in an assortment of varied lo- nutritional supplementation of mares. Visible stifle joint distention caused by disturbance of normal ma- heal or become stable enough never cations, and due to unpredictable 2) After seven months of preg- nancy,the nutrient requirements be- come significantly greater than the mare’s maintenance requirements. 3) A mare’s nutrient requirements increase significantly after foaling because during the first three months of lactation, mares produce milk at a rate equal to about 3% of their OCDTM Pellets provide the body weight per day. fundamental nutrients for 4) Giving mineral supplements healthy bone development to a suckling is unnecessary until it reaches 90 days of age. and aids in resolving skeletal 5) From weaning to 12 months injuries and joint pain. of age is the most critical stage of growth for avoiding developmen- tal orthopedic disease,such as OCD. 6) Yearlings are less likely to de- velop OCD than are younger horses. Commercially available nutritional supplements high in copper are avail- able and have mixed therapeutic re- The only BONE supplement containing sults. Qualified professional advice JOINT ® proven supplement CORTA-FLX is recommended prior to choosing the best treatment for horses affected www.OCDPELLETS.com with OCD problems.

866-392-2363 Gregory Beroza, D.V.M., is founder of the Long Island Equine Medical Center in Huntington Doc’sTM Station, New York. He is a practicing veteri- narian of 31 years with board certification in Products, Inc. AAEP Booth #8107 both surgery and in practice. He is founder of Dr. Douglas R. Beebe EquiScan Nuclear Diagnostic Imaging and he Located in Lexington, KY publishes regularly under HorseDoc, “Talking Horses,” at www.horsedoc.com.

32 THOROUGHBRED TIMES October 22, 2011