alarm bells for me

quote.... is their any way i can make him viscous at all ...... you really do not want that!!thats not a guard dog its a dangerous dog!!!

sent away for training... ... takes time and effort to have a bond with your dog,that involves training....and is more likely to want to naturally protect you for it.

an 18month dog of this breed is still a BABY..and could also be in another 'fear stage'

too much pressure on him to 'perform' , and in a way i dont think you could handle if he even did!!

all young dobes ive met take time to mature and some can be a bit 'scitty' until they do.

please try and think of another alarm system...preferably not a living one.

Its my understanding that a protection dog will only be 'vicious' on command

My boy will bark and be rowdy at the gate which is sufficient for passing strangers and when he is with me he is confident i can deal with most situations so hes generally a nice guy.

If he is not happy in a situation he will freeze and look up under his eyebrows and show a lot of white, his face will tighten and if he is not swiftly removed from the situation he will lunge

Only on 2 occasions has he been openly defensive from a distance. Once when a local chap who is slightly less able mentally and physically appeared round the corner of a buildling whilst we were sat relaxing outside the village shop. He was some 50yards away but T stood up grew about 2 feet and had full hackles and gave a very menancing growl. The second occasion was when a rather large (friendly) chap appeared round a corner with his wife and again same thing proper menancing growl and hackles and he was ready to launch. I would love to know what goes through his mind sometimes, as he has never been beaten or had anyone be mean to him (over my dead still twitching body!) so it could be that its just one of those things that only a Dobe mind knows. Spike may only be being 'tough' in the car and when you are around as he has you as back up

Did he have exposure to black africans in his formative months?

If it were me i would:

1st - Go back to that dog school and interrogate them as to how/if they involved Black africans in any part of his training (i realise this sounds politically incorrect in this country but not the case in SA)

2nd - Enlist the help of your gardeners to try and teach him that black africans are not to be feared

Good training means a dog will only react on command. I honestly think that he has been beaten/treated roughly

it would be interesting to see how he behaved around his 'trainer' at braveheart

We do not train our dogs here in the UK to attack/threaten people of different ethnic origins as is done in SA by some people.

Here it is not legal to have a guard dog that does not have a handler in attendance.

You do not know what was done to your dog when you sent the dog away for training-something NOT to be recommended especially for dogs wanted to perform"protection"work

As others have written-a good electronic alarm security system would be better for you than putting a dog you have not personally trained for protection work between you & any unwanted intruders.

A Dobermann will generally naturally protect his own enviroment to be honest and only reacting on command isn't much use if the owner isn't there to give the command and the OP says she's out at work. Dobermanns tend to think for themselves and act in the absence of instructions. They are a naturally wary confident breed. Mine would only react if they thought there was something to react to, other than that they would be very watchful and on their toes.
He doesn't sound at all confident to me tbh he sounds fearful, why does he become very aggressive in the car and house when someone approaches? There is a huge difference between barking to give warning and alert the owner and being very aggressive. Maybe it's not being explained very well but he sounds stressed and scared to me. I think he'd be better off in the house rather than out in the garden with the gardeners and you not knowing what's going on while you're not there.

i think we have to respect that the OP comes from a tottaly different culture to us, and to be honest did nto see anywhere in her post that she had had him trained to attack Black people.

She said he was afraid of black people.