Ok so I have a 1.5 year old female bullmastiff. Raised around chickens. She was fine the first year and now she is a savage!!!! She killed 2 chickens this past week (they are young pullets)....I think she caught them and just crushed them and then we found them burried in the yard. Now this morning we found another one eviserated!!!! She is in a fenced in yard and the pullets I think keep getting in through the picket fence. I am going to chicken wire the bottom of the picket fence today. We tried to use the training collar (electric) on the dog the other day, but I guess she knows nothing happens when we are not there because she got the chicken last night or this morning...... My older hens know not to go in the yard....they have a whole acre to roam where the dog can't go.....I just don't know why the pullets aren't putting two and two together!!!! They have gotten chased before Is there anything I can do, besides getting rid of dog/chickens, the chickens hate being "cooped" up all day!