Blood in droppings can be a symptom of coccidiosis. You can get Corid from the feed store, and add 1 1/2 tsp of the powder or 2 tsp of the liquid Corid per gallon of water as their only source, for 7 days. Do you have other chickens? So someone just left 2 pullets in a carrier on the side of the road? If you have other chickens or poultry, it would be helpful to quarantine them for at least 30 days in case of an illness, which sometimes are contagious and make them carriers.