The Nevada Department of Agriculture is urging extreme caution after two separate collisions on Highway 50 near Dayton in early Thursday morning. One motorist suffered minor injuries when a horse came through the windshield and was killed on impact. The other collision was a hit-and-run, and the horse was euthanized due to severe injuries. NDA has been working with the Department of Transportation over the past year on installing fencing and cattle guards on this stretch of Highway 50 between Carson City and Silver Springs.