We have had Stella since March when she was 8 weeks old. She always did some biting and broke skin but attributed it to sharp baby teeth. Now it seems she is very aggressive when she jumps up on me scratches me and yes, the skin does get broken. most of this has been on my arms. I cross them so she cannot get to them and I yell OW. Not sure if she is scratch ing more than biting to draw blood, but there is definitely a lot of teeth showing. Seems to happen more when we are outside and she is very excited. Cannot walk towards house as she goes for my ankles and pants when she is like this. Usually this occurs around 5 to 6 in the evening but yesterday when I let her out and after awhile I went to go find her and she came running towards me and jumped up towards my face grabbed at my bicep on my arm. I started screaming. This was in the morning. When she is in her "cujo" mood she does not listen. Saying "no" does not seem to make her more aggressive but she certainly does not stop what she is doing.