Missing Edith

Poor Edith the chicken was killed tonight. We came home this evening and the chickens were out (we still aren't sure how the gate got unlocked.... Eli??). Our brown chicken, Edith was laying under the hen house and she was suffering from being mauled. Josh took care of her and then Isaac helped him bury her near our woods. We are 99.9% sure it was Sampson because he had ahold of Georgie (our black chicken) the other night and hurt her pretty bad. If anyone has any suggestions on keeping dogs from killing chickens let me know. Of course we aren't going to get rid of Sampson; but I don't want our other two chickens killed either.