The three round dark spots on this horse's hindquarters, one behind the flank and two near the gaskin, appear to be Bend-Or spots. (click image to enlarge)
Bend-Or spots (or Ben d'Or, Smuts, or Grease Spots) are a type of spotted marking found on horses. They are fairly rare and range in color from slightly darker than the horse's coat to an almost-black shade. These random spots are most commonly seen on palominos, chestnuts, and darker horses, and may not appear until the horse is several years old. It is still unknown what causes these markings, as they do not appear to be related to other spotting patterns. However, they are often correlated with horses showing sooty traits. More may appear as the horse ages.
Unrelated patterns may be confused with Bend-Or spots. Some roan horses have patches of darker hairs called "corn marks" or "corn spots." While these resemble Bend-Or spots, they are linked to solid-colored hair growing in over minor cuts or scratches to the skin, and thus the underlying genetic cause appears to be unrelated. Another pattern seen primarily in some gray horses is dappling, the presence of darker hairs in round shapes against a lighter hair coat. However, dapples are an intermediate stage of the graying process, and will only last a few years.