I agree with Lil. Get on your knees where you last saw the deer. The sign is there you just have to look harder and smarter. Crawl in the direction the deer went and see what it sees. Check all trails you come across from your knees in both directions. Look for upturned dirt and leaves, broken branches pointing in the direction of travel, anything that could direct you till you can find better sign of the hit. Its first moves will most likely be right through bushes and undergrowth and you need to stick your head in those too. Lots of times you can almost invision the route these things will take when your at their level. KEEP LOOKING