Hi,
Sounds typical of a field dog - labs, retrievers, springer spaniels and so on. No animal welfare charity, and very few vets, approve of these collars.
One problem is that the 'charge' is variable, and there may be a temptation for the user to keep increasing the level of shock to an unacceptable level.
I suggest that you ask for a referral to a canine behaviourist such as Dr Roger Mugford(If you live in the UK). There is also a list of behaviourists elsewhere on the Vetclick site under 'referrals'.