I agree with Lisa! Make sure to socialize her with all types of people AND animals. I really think my Sandy wasn't socialized and now she is aggressive towards other dogs. I think it all stems from not knowing how to act around them. She doesn't realize "butt sniffing" is the dog equivalent of "hi, how are you?" Instead she puts her butt down, growls and nips! We have two cats at home and she is totally fine with them!
Carrie