Aggressive

Question
Hi I have a 3 year old female Australian shepherd and she's been passed down 2 time. We are the 3rd one she was guit for a while then opened up. She is pretty agressive towards others that come over and the grandchildern She will lunge at them but not bit yet.
Some people she's got to know she some what ok.
Any ideas

Answer
If the dog is lunging then she should be contained away from the grandchildren. Do not risk a bite.  Aggression cases should not be diagnosed or treated over the Internet, so I would recommend a couple of things.  First, have your veterinarian do a complete thyroid panel on the dog to see if she is hypothyroid - that can cause or escalate aggressive behavior.  The test is about $100 but the medication, if she needs it, is fairly inexpensive.  Secondly, hire a clicker trainer or behaviorist to work with her to lessen her fear of strangers.  Sadly, this is one of the more difficult problems to reverse, so most trainers are still going to tell you to manage her by keeping her crated when you have company, or by training her to wear a soft muzzle such as the Baskerville.  You can find a trainer through one of these sites: Pet Professional Guild, Academy for Dog Trainers, Karen Pryor Academy, Peaceable Paws.