Dog biting his side and getting a bald patch?

We have has our dog for about 5 weeks now and his previous owner showed me his side where his fur was a bit thin, she said he bites himself there when he is nervous.
She got him from the RSPCA and although I do feel he trusts us, I think there is always something there and he does still seem to be nervous in certain ways.
It there anyway I can stop him doing this? I have never actually caught him doing it, it could be at night I suppose but sometimes he has a really obvious bald patch, he is a Dobermann so his fur is obviously very short and smooth so I think that makes it more noticable.
I'm just worried that it may get sore there if he carries on when there is less fur to chew.

Hi there.

If you have never seen him doing it, he must either do it when he is alone (possibly a type of seperation anxiety?) or it isn't due to him biting it.

Is he left alone very much? Is he by himself over night and does he seem to settle well?

What food do you feed him and how are his poos? The reason I ask is that my nervous rescue bitch is allergic to some foods. One food I changed her on to had a marked effect - she started pulling out all her chest hair and it went very, very thin. But she was doing this quite constantly - it was obvious.

Perhaps a change in diet and supplements to improve skin/coat condition might help?

It would also be worth having him checked over by the vet - there are various conditions that can cause bald patches.

Whilst you are at the vets, get him/her to check your dogs anal glands as they tended to nibble their flanks when the glands are blocked.

Its an easy if unpleasant job to unblock them,

Thalice's Mum

Thanks for your replies.
He is left alone for a few hours 4 days a week and he's alone overnight and seems to settle fine.
I am considering changing his diet anyway as his skin seems dry so hopefully if this is something to do with it, that may help.
I think I'll get the vet to check him over anyway just to be sure, I didn't really think about allergies or anal glands or anything.
Thanks very much for these suggestions, it sounds like it may turn out to something different than I had thought.
Thanks again!