
Hi there adrienne,
The first thing to do is...calm down, he's a dog :-D :-D.....No, seriously, he is 9 months old and of course he is getting frisky with the laaydies - I would have serious reservations if he
wasn't ;-)
I doubt that he will turn into a 'sex pest' when he is matured but only time will tell. They are like people, some like the opposite sex more than others, only
you will be able to decide that as and when he reaches maturity. Great that you are taking him to obedience classes as he will experience a wide variety of breeds and sex's. Be aware that in the near future he may test your patience 'off lead'- his nose will lead him ;-) So have a 'long line' in stock for these occasions and be prepared to have to 're-educate him in this department. Being a dog, the chances are that he will chase a bitch in heat - and long before he matures - i.e.
NOW Re castration - it is
no guarantee. This may help alongside a training regime but certainly IME won't alter the overall character of the dog.
Your Vet is to be applauded in saying that he won't castrate before 12 months - a lot of Vets want puppy owners to have them done as early as 6 months or before. I personally, owning a large breed, would not consider getting mine done before 2 years. The general rule is the larger the breed the later you have them done because of physical/mental natural maturity.
In my own case I have an entire 6 yr old male who has done the 'Kevin stage' and a 3yr old female who was spayed at 2rys 8 months purely because she was suffering from 'hormone rage' - that and the mammary cancer threat along with deciding that we weren't going to breed from her made our minds up. Our male lived throughout 2 of her seasons but when younger could have quite easily been labelled as a 'sex pest'. Make no mistake - our Male still, when out, sniffs a fertile/or not.. female, behaves like a delinquent, but it is controllable through training/keeping his small mind busy and well......bribery :-D :-D
HTH