Help! Giant breed aggressive dog on dog & 'Aplha' issues

[i'mstomped!]

Hi there

I own a whopping 11.5 stone male harlequin great dane x mastiff whom i rescued at 8 months old. At the time, the ever-so-skinny sorry state that came to greet me was very timid and totally untrained and had no manners and due to feeling sorry for him, I brought him home. I immediately castrated him and began socialising him to gain the social skills he greatly lacked. Things were going ok until he suffered an attack when he and another dog were off the lead. i believe this was the turning point and as my dog grew...and grew... and grew (he now stands at 5'6 on his hind legs) his stature and dominence altered, both towards other dogs and myself and my husband (less so). I now feel out of control as he is heavier than me and has immense strength to pull, even with a halter. He cannot walk without a muzzle and frankly is just not very pleasant to be around. I really need some info as to how i should behave when he shows dominence when out walking and when avoidance isn't an option..its almost impossible not to meet other dogs and as each day goes by he worsens. Any info greatly appreciated x

[MaxHollyNoah]

Hi there.
I didn't know the unit of "stone" so I Googled it and got surprised! It is like 14 pounds! That means your dog is over 150 pounds!

To be honest with you, I would recommend you seek a help from a professional trainer/behaviorist, just because of the size of your dog and the breed. I think Mastiff is pretty protective thus not very friendly to strangers, therefore, you might want to avoid any potential injuries.

One of my dogs got aggressive from an incident. He got lunged and barked at by a pitbull a few months after we adopted him and it was clearly a turning point for him. We have been working on the problem since then and things got much much better, I would say 80% corrected. However, it took us more than half a year, with trainings and socializing with other dogs once a week at doggie day care. You said your dog is so strong and he pulls so much, I don't know if you can keep up with him while you try to control him. Basic obedience training is absolutely necessary so you might want to start train him sit, down and stay every day for half an hour to see how he does...

I am sorry I can not come up with a better solution. Maybe someone will be able to help you.