despite being very well socialised, exercised etc our jack russell has always been very protective and not social (read attack 1st make friends later ) towards other dogs or people.
She is walked regularly ( on lead and with a muzzle on), is not left on her own for long periods etc etc
She has always been very cuddly with my children and never aggressive to them , but unfortunately has now bitten and gone for some people who have come into our house regularly.
Not something I want to continue obviously.. any suggestions? Would a dog behaviour expert assist?