I have a female english bulldog puppy who is 2 months and 3 weeks old. Her name is Nelly and I have a problem with starting a leash for her. Whenever I tried to take her on a leash, she just lays down there and sometimes she pull back and won't move even a step. I've started from a week ago and whenever I tried to walk with her with a leash, she will get angry and start crying . I also have a male bulldog who is 6 months old named Piggy, I taught him with a leash before when he was 4 months old and it was really easy....so I'm not sure if the problem comes from her behavior or her age? Please help