Hi I have a 12 month old lab and last night in training school, he did something he has never ever done before, he growled at another dog and whilst doing a dumbell retrieve caught the scent of a bitch on the floor and his lips quivered and he was slobbering!  My little boy is growing up!  Will he grow out of this behaviour?  I don't want to castrate if poss because I might put him out to stud.  I was so proud in a weird kind of way because my little clumsy yellow puppy has grown into a big handsome dog!

Anyone?

It might be that hes mautring to the stage where he's noticing other bitches, she could be near her season. if thats the case then your little boy will be most intrested. as for the growling its quite normal for them to do this but it should not be rewarded as it could turn nasty but mostly very annoying for you. One way is to tell him off as hes doing it and praise him for ignoring all the other dogs. he will learn in time that he gets a treat/praise from you if he ignores the dogs and a telling off if he doesn't. Sometimes i pin mine to the floor if he wont stop going for another dog - he doesnt like it so stops and then i let him get up when hes calm. But with it being the first time it should be easy to stop him if you nip it in the bud early.