You have not mentioned whether it's a male and female? If it's a male, spaying is optional. It depends what is the temperament of your pet. If he is very protective or becomes ferocious with other dogs, if he has behavioural problems like habit of biting and growling on family members, you should neuter your dog.
Usually, the dog is not born bad or is not born with bad habbits, it's the owner who makes the dog become bad. If you don't socialize your puppy from beginning, don't exercise them properly, don't train them, keep them confined, you are likely to have a bad dog, but if you exercise your dog very well, train them well from beginning, socialize them well, you are likely to have a dog that's very docile .
So if you have a dog kept among good owners, you have a problem-free dog and you don't really have to spay them. But you may still consider neutering your male, because, spayed dogs are less-vulnerable to prostate cancer and are likely to live more.
On the other hand, if you have a female dog and if you are not into breeding, you must spay her.