Behavior/aggression

Question
Hello Kristen,
I'm Megan and i was hoping you could give me advice or a suggestion on what to do. We have recently bought a three year old spayed Rottwiler, her diet conatins Old royd dog food, Purina wet dog food, and an occasional dog biscut, She is mainly an inside dog. We have noticed that when we type on the computer, play with nikki (the dog's name),or pet her, she will sometimes leap growl and snap at one of us. For example, my seven year old sister gave the dog an rub on her head,as soon as she did so Nikki leaped up and snapped at her.Aonther example is, we had friends over last night and the parent of one was playing a game of fetch with Nikki when she became very aggresive and growled at her when she took the toy from the ground. Also she pushes my sister around the house and won't leave her be.
 Thanks for your time and hoping to hear from you soon,
            Megan and Nikki

Answer
Megan, I would highly recommend that you hire a professional trainer/behaviorist, who has experience dealing with aggression, ASAP. It appears that your dog sees herself as an alpha, and her behavior could soon become harmful to you, your family, and your friends. Open the phone book, and start calling trainers right now. Your dog needs some discipline, she needs to learn that humans are above her in rank, and that aggressive behavior is unacceptable and intolerable. She is a big dog that could easily cause serious injuries to an adult, not to mention your 7-year old sister.

Kristen

PS - I'd also recommend that you take a few minutes to read the information on the following web page, in regards to dog food. You might as well be feeding your dog cardboard that's been soaked in meat juices and chemicals, feeding Ol' Roy and Purina.

http://dogfoods.angelfire.com