Mastiffs are extremely stubborn and independent. They can feel your frustration and if you start raising your voice, they shut down on you and stop listening.
When training and walking, take a few deep breaths. With shoulders back, walk with confidence and train with confidence.
They listen more to a confident person who is stern but calm. Teach him what you want him to do.
Yes! 100 % ^^^ I couldn't agree more.
Hiring a trainer, preferably one who is familiar in dealing with large, powerful, stubborn breeds, (and aggressive dogs, as in my case also) IMO is essential if you are not experienced yourself. I am very happy with the money I've spent on Luther's training (he's a Cane Corso, unaltered, 17 months old), and I've spend a good amount, and he's still in training... it's a life process. This is a serious working dog with tremendous strength. Very few people really have the knowledge, facilities, or skills necessary to manage these breeds.
However, his forum is truly AMAZING, many people on here are VERY serious about their mastiffs and have the knowledge and experience to help you out with anything and everything. Reading through all the threads has helped me out a lot, and I've gotten very helpful advice on dealing specifically with my own CC; there is such a wealth of information here.
Thanks to
musicdeb, and her vast and valuable knowledge, you already have gotten some good advice, hopefully some Dogo owners will come on shortly and offer up more of their expertise.
Please keep in mind that adopted/rescued dog will usually have "issues" and will require a ton of work to get him rehabilitated, this takes having great patience and time. This is what I am dealing with, with my CC. Every day I learn more about him, and about new things that need to be worked though... I'll admit, for me it's a steep learning curve.
In the beginning he was reactive to EVERYTHING, people, dogs, cars, noises - but I worked with him, got him a serious reputable pro trainer familiar with working breeds (one who takes on hard cases, aggressive dogs, bully breeds, etc.), started socializing him (since he was never properly socialized), got him out walking (he was never walked) twice a day on structured 2 mile walks, desensitizing him, counter conditioning, set boundaries, countless repetitions in everyday training, absolute consistency, staying calm patient and understanding, and pretty much keeping an eye on him 24/7. Dealing with him IS a challenge, but after almost 3 months of this nonstop training he is progressing nicely as I am working on "rehabilitating" him.
I do not have kids, and do not plan on having any, so honestly I can not give you any advice on how to specifically deal with him and children, since I never had to work through it. All I can say is that these are incredibly powerful guardian dogs with specific needs, they are willful, obstinate, and will challenge you (sadly many people don't realize this, and that is why in a lot of cases they end up in shelters or PTS). They need continuous training and supervision especially when they are unstable.
In Luthers' case, he IS a dog that requires a ton of patience and training because of his "issues", otherwise he can become a liability with a potential to do a lot more damage then your average pet dog. He is very wary of all new people, so I try to stay a good distance away from them on our daily walks, usually 10 feet is a good comfortable distance for him. And I always keep him on a leash, (although he is now off-leash trained and always comes when I call him and listens incredibly well), I just don't trust other people and their possible reactions to him, nor do I trust him... I simply do not know him well enough. In group class he wears a muzzle, since he hates when the trainer gets into his personal space, or anyone else for that matter, (except for me, he seems to trust me) so we're working on that one also. But for the most part as long as everyone stays away from him, and doesn't get too close he remains stable and shows no aggression.
To get him use to wearing a muzzle I did the whole treat through the muzzle thing, and having him wear it for short periods of time around the house, and sometimes on our walks. Also to the vet, and if we're going somewhere where there is going to be lots of strangers. He certainly does not wear it all the time, and never longer then an hour at a time, but it is for just in case.
When introducing him to new people, i.e., friends, family, etc., we always do the "no touch, no talk, no eye contact" initially. We don't force him to interact with people unless he wants to, and it's always under my close supervision.
IMO your Dogo's issues are workable, but as already mentioned it will take serious daily work, patience, time (maybe even up to a year+), and management. All that I've mentioned is not meant for you to question your decision in rescuing your pup, but just to illustrate what it's been like for me dealing with a similar type of dog. I guess this is me just being very cautious as an owner of a very powerful guardian breed. I am sure you understand.
One of the first things that I've learned about these breeds was that they are amazing, intelligent, loyal guardian dogs, HOWEVER they are not for everyone. Knowing what I know now, I totally agree. I still have a lot of work to do with Luther, but I'm very pleased with the progress he's made. Like I've already said, he's definitely a challenge, and a work in progress; but aren't we all? At the end of the day, I feel all that hard work is totally worth it.
Welcome, best wishes, and good luck!