behaviour

Question
We have a beautiful German Sheperd-hound mix. She weighs in at 105lbs. She is very loveable and friendly towards people only after she sees we have accepted them. She is very protective of us, so much so I cannot open the front door to any stranger, I have to go through the garage. She is 3 yrs. old and has recently started growling not only at strangers but at us when she doesn't get her way. I know she would never bite us and we do not submit to her growling, rather we stand up to it and try to change her mind. Is this normal behaviour? Is it something we need to worry about? It's like she just realized she can growl and is using it to try to intimidate to get her way. Also at 105lbs she is on the heavy side, We've tried different foods, but the diet foods leave her starving and heading for the trash or the counters for bread, she loves bread. She is a gluten. Could you suggest and good brand of food that will help her to both feel satisfied and help to lose weight.
Thank you.  

Answer
Hi Diana,  First off, what do you do when she growls at you.  Also, have you had her thyroid checked or had her checked for diabetes?  A  lot of GSD's have thyroid problems and hounds & GSD's are prone to diabetes which both could explain the weight problem and the starving thing.  I would get a blood workup done at your vet and also let me know what you are doing about the aggression so I can give you some advice on what to do about it.

Dawn