ENOSTOSIS-LIKE LESIONS IN THE LONG BONES OF 10 HORSES - SCINTIGRAPHICAND RADIOGRAPHIC FEATURES

Ten horses admitted for lameness evaluation including bone scintigraph y had enostosis-like lesions, described scintigraphically as focal or multifocal areas of intense increased radioisotope uptake within the m edullary cavity of one or more long bones, and radiographically as one or multiple round to irregularly shaped radiopacities within the medu llary cavity, often in close proximity to the nutrient foramen, There were 6 Thoroughbreds, one male, one female and 4 geldings, 3 Standardb reds, all geldings and one Appaloosa gelding; age 3-10 years, Enostosi s-like lesions were seen in the tibia (5 horses), radius (3 horses), h umerus (one horse) and third metatarsal bone (MT-m) (4 horses), The nu mber of affected bones in each horse was 1-3, Of 16 affected limbs, th ere were 9 hindlimbs and 7 forelimbs, Enostosis-like lesions were cons idered a possible cause of lameness in 5 horses, but were considered i ncidental findings in the other horses, Lesions thought to cause lamen ess were seen in the tibia (2 horses), MT-III (one horse) and in the r adius (4 horses), Lameness resolved after horses were rested (2-6 mont hs) and given nonsteroidal anti-inflammatory drugs (4 horses), Follow- up scintigraphic examination in 3 horses (2, 6 and 9 months later, res pectively) revealed normal radioisotope uptake in the affected areas.