I have a 4 yr old Patterdale Terrier Cross dog.He wont let us out of the house and he also wont let visitors in. He hurls himself at the door when tradesmen call in fact anyone who visits. we have to take him out of the room as he goes for their legs.He trys at times to dominate the settee when we get up from our seat. When he is on walks he attacks other dogs if he thinks they are aggressive. should we seek outside help or get the info from books as the charges can be anything up to £200 with no garantees. help.   

A well qualified, experienced berhaviourist should be consulted.

What they will charge is small in comparision to the financial and emotional damages which you might be up for should your dog actually bite anyone.

Have to agree, to attempt to help without seeing the dog first hand could in this case be dangerous. Ask you vet for a referral, if you are insured it should cover the fees. If the vet cant help try looking here for advice

I also agree. Have you had your dog long? It would be interesting to know if he has done this since puppyhood, or if there are reasons that he behaves like it.(e.g. if he is a rescue who may have had bad experiences you dont know about )
A behaviourist will look at and analyse YOUR behaviour and handling of the situations, as well as your dog, which can't be done by reading a book.
I know it is expensive, but it would cost the same if he needed vet care for a physical condition, an operation maybe. Is he insured? Some insurance policies will cover this kind of thing if your vet recommends it.

Get professional help immediately from a registered pet behaviourist such as those that belong to the APBC; you will need referral from a vet before you will be seen; this is in order that medical conditions have been ruled out.

This sounds like a multiple resource guarder (house, settee, you) and therefore you need a structured programme to follow in order to desensitise and counter condition this behaviour.  You will need expert advice on this; it takes a long time and the degree of success you can expect strongly depends on how seriously and how consistently you treat the dog.  The behaviourist will not come in and "wave a magic wand" but work with you over a long period in order to helpy you help your dog become more socially acceptable.

Books are great for those who have a significant amount of experience but you sound as though you and your dog would benefit from a more 1:1 approach.

HTH and Good Luck

I agree you def. need professional help in this case. I feel too that any Patterdale is very much a working dog and he may well be making himself work as he sees it, because he has none to do. It may be that with help he can be turned around. Good luck :)

Lindsay