Thanks people for your replies. My Toby is a Heinz 57 breed, he actually looks like a collie, but with a fatter nose and he is orange, beautiful, really.
About letting children near him to pet him whilst he is on the lead, will they be safe as he has nipped my nephew. Not to draw blood but just as a warning I think, not to come too near.
Thanks for the very sensible advice, though and I will put it into practice