Difference between neutering and vasectomy is that in case of neutering you completely cut away male testicles and he doesnāt have anymore 80 percent of his testosterone. That means that typical male behaviour like marking, leg lifting, humping, aggressiveness etc usually stops at all or is significantly reduced. Ability to produce sperm is seized, so dog becomes sterile. As adrenal glands still produce a bit of testosterone (even in females), itās usually enough for normal life.
In case of vasectomy, only ducts which carry sperm outside are tied. That means, testicles are still there and they produce testosterone. It goes straight into blood, ducts are not involved, so vasectomy takes away only one ability - produce sperm and become a father. All the rest is intact.
So, with all respect to vasectomy, it absolutely cannot produce any effect upon behavioural issues like leg lifting or humping or marking. I think it has almost no significance besides from prevention unwanted puppies. So if you have female dogs or there can be a situation that he is unattended and possibly meet any dog ladies...then go for vasectomy.
Personally I left my male bulldog intact, because so far he didnāt have any behavioural issues. And he cannot be involved into any sexual activity and become a father because first of all he is never left unattended and second he is such a coward, smallest female doggie makes him hide under my skirt
Itās your decision of course, but first of all, ask yourself what you want to achieve with surgery? Does he hump, mark, excessively lifts leg? Is he aggressive?
There is no thing like a harmless surgery. And now there is a lot of data that early neutering is cause of health issues.
I come from Europe and there common rule is to leave male dogs intact, unless dog shows behavioural problems. Why to make an unnecessary expensive surgery ?