Yesterday one of my chickens left a large bloody splash on the ramp. I assumed it to be intestinal shedding.. Today we discovered a liquidy runny green and white poop with blood in it. There's no nasal or eye discharge and everything else looks normal externally. They get DE mixed with their feed, but last time I gave them any was a little over a week ago. I picked up some durvet sulfadimethoxine thinking to treat for coccidia, but my chickens have been on my dirt since Nov 2009 and the inflicted chicken is somewhere between 2 and half to 3yrs old and package says do not give to chickens over 16wks of age. Last chickens introduced to flock were back in April. Any suggestions or what I need to do?