Figure 1.

Comparison of normal and DSLD-affected tendons. A. Only thin septa (*) separate bundles of collagen and elastic fibers in a normal tendon. Hematoxylin & eosin, magnification × 200. B. A section of DSLD-affected tendon reveals PG deposits (*) between collagen fibers and in septa. Hematoxylin & eosin, magnification × 200. C. A section of tendon from a horse without DSLD shows the presence of fibrosis or scar tissue (*) between collagen fibers and in septa. Hematoxylin & eosin, magnification × 200. D. A proliferative lesion found in one DSLD case consists of swirls of active fibroblasts in young, well vascularized tissue. Hematoxylin & eosin, magnification × 200.