Advice is to have a sharp pair of scissors always available for these kinds of incidents. Similar happened with Snowie (as a puppy) and a pug....
Have you considered taking him with you on the school run? Lovely opportunity for socialization - kids of all sizes, screaming kids, cars, general...
Before deciding about the farm, how is the other lab treated there? What training methods do they use? I would hate to be in your situation,...
