Great Dane behavioural problem

Question
Hi Ken, My wife and son (15 years old) have an 8 month old fawn Male Dane. In general he is a terrific dog, fully house trained, occasionally gets on the sofa, etc. He has been through a 6-week puppy training course. He is very well cared for and already much loved.

The problem: occasionally very aggressive. He will growl fiercely and bear his teeth if you approach when he has a bone, he will growl nastily at random times for no apparent reason. I would describe him as a nervous dog, however he is also extremely affectionate at other times. He is playful and we play tug of war without any aggression and after a while he's happy and returns to his bed. I would be very interested if you have an opinion.

Thanks, Dave Cleaver West Sussex

Answer
1.  Stop giving him bones, they are unnecessary and will wear his teeth down.

2.  Stop playing tug-of-war, it encourages him to protect his belongings when he should have been trained to give up whatever he has when he is told.

3.  Take him to training classes where they will teach you to train him properly.

4.  Treat him like a dog and not a toy to be played with or a child to be given in to.  Dogs should be trained to do as they are told when they are told.  A 150 lb dog must be kept in his place or he willdominate you, probably end up biting someone and having to be destroyed.

Ken