I have unintentionally have in my possession a 4 year old mastiff cross, he came to me just before xmas due to a relationship breakup in the family. He had been in the same home since a puppy, but for a large part of it locked in a small room for a lot of the time, Despite this, although he was very much under weight, he has settled ok, he is totally house trained, not chewed anything up, super on his lead. good with other dogs and cats, and seems fine with my grandchildren even though always supervised. But he is obsessive with me, he follows me around like a lost sheep, if I am in the house on my own he is a super dog quiet and obedient. If anybody tries to come near me or show any affection towards me he puts himself between me and the other person, not exactly growling but giving warning to stay away, he also does this when my grandchildren try to sit by me. The minute the door goes he erupts into a frenzy of barking, he charges at people when they enter the room barking, he also does this when people get up to leave. He is so big now that he has got up to weight, I cannot hold him when he decides to charge. But last night he was lying in his bed and my husband went to put him out before bed, he wouldn't get up from his bed so hubby just took hold of his collar to pull him up and he went to bite him. I am really fond of this dog and thought that i was able to offer him a home he deserves, having given him a lot of understanding due to his past, to try and offer him a stable family home, but this behaviour is unsettling me and any advice would be appreciated.

You need professional help from a GOOD behaviourist that understands this breed.

The dog is showing the traits he should show - protecting his master - you (afterall, he is a guarding breed), but he is doing this in situations he shouldn't be.

I have my first Mastiff who will be 6 yrs soon, I've had him form a pup. I read up a lot about the breed and general dog behaviour before getting him but was still surprised at how different they are to other dogs, you really do need to be calm & confidant without being confrontational or bullying.
It's understandable that his behaviour will worry you, however, being worried will make this guarding behaviour worse, he will be highly tuned into how you feel and if he feels you are nervous he will act upon it, so you have a vicious circle.

Please get professional help A.S.A.P.

In the mean time keep him shut away from visitors - this is purely as a management strategy to a) avoid anybody getting hurt and b) to stop him getting the chance to practice the unwanted behaviour. You've said he's to strong for you to hold if he charges, so best to get advice in how properly deal with this form a good behaviourist.

I would keep him away from children FULL STOP until you have seen a GOOD behaviourist, the size & strength alone can cause injury to children just from the dog knocking them over, it's not worth the risk.

> he wouldn't get up from his bed so hubby just took hold of his collar to pull him up and he went to bite him

Do not let anybody pull his collar or even pull on his lead, these dogs do not take well to confrontation - your dog is seeing this as confrontation. This breed should have extensive socialisation and training when young, he obviously does not know how he should behave or what is/is not a threat, for him any person that he does not 100% trust, pulling on it's collar is asking for trouble. If the dog needs to be moved, LURE him with something he likes, eg. a dog treat, or go to the fridge, rustle around in there and call him out for a morsel of something tasty from the fridge (ham, chicken, cheese, etc.).
I would also have this dog muzzled when out of the house for public safety.

> But he is obsessive with me, he follows me around like a lost sheep,

He obviously has a lot of Mastiff traits, this is Mastiff behaviour. I've just gone out into my garden for a ciggy - my dog followed me out, sat & waited for me, now he's followed me back in and is laying at my feet while I type (in in the kitchen). I'll be going back out into the garden soon to clean the rabbits out, he'll come out with me, sit  down and keep an eye on me.

I'll say it again, you need GOOD, professional advice. This dog is not just showing behaviour problems, he is showing breed traits that are problematic, somebody that knows what they are doing needs to asses him - is he like this due to lack of training/socialisation? - is he like this because he is insecure? is he like this because you are not sure how to handle him so he's taking charge?, is he like this due to breeding (what breed is the 'cross' in his parentage)? Somebody who knows what they are doing needs to get to the bottom of this and advise accordingly. There is possibly an awfull lot of work to be done with him.
Socialisation & training should be extensive when young AND on-going, if this dog has not had that, you may need to make a decision based on the safety of people and have him put to sleep.

Any help you get for him needs to be calm, KIND, consistent methods that avoid harsh treatment, punishments, confrontation and bulling. No Cesar Milan style 'rehabilitation', no 'leash jerks' or shouting. Anybody not wanting to take a kind, reward-based approach with him are money-grabbing charlatans.

Thanks for the comments i appreciate the input. I probably painted a worse picture of him, but that does not detract from the issues that are there. When people arrive he runs at the door franticly barking and continues to bark until they come in and sit down, once seated, he lies downs and goes back to sleep. Out on his lead he is a gentlemen, we go to populated places he walks by my side, passes other dogs and people and i have encouraged people to stop and pay attention to him. he stands and let strangers stroke him and is ok with other dogs. if i let him off the lead he walks by my side or just potters off around me but comes straight back if i call him. The main issues I think are in the house. I have had boxers all my life so am not a new dog owner, and so have used some of the tactics you suggested with regards to looking for alternative methods to gain the same result, such as using toys or biscuits etc to get him off his bed or to get him to go somewhere he refuses to go. these always work, i use the same methods with some of my horses. My sister was a mastiff owner having lost her old boy recently so I have made myself aware of some of the traits, I suppose the problem with this one is that I have no idea of the other side of parentage, and have only a slight clue to the sort of life he has led previously, and I dont think it was a pleasant existence. I have made enquiries with the local vets for some reputable dog behaviourist and hopefully they will get back to me soon. I want to give this chap a good life, I dont doubt he loves me, just too much. I love the fact that if I am baking, he lies at my feet, if I go to the loo he waits outside, he knows he is not allowed in my bedroom, and even with the bedroom door open he will just sit at the top of the stairs and not venture in. He has so many good points, I just hope that we can overcome these issues safely.

I endorse everything that ML has written.

If you are looking for a behaviourist try the UKRCB or APBC. These are both organisations that are recognised and governed by the APDT (Animal Training and Behaviour council) which is the nearest thing we have to an industry regulator. Members of either organisation must have both academic qualifications as well as extensive hands on experience, members are also assessed before achieving accreditation.