The traditional age for neutering a puppy is from 6 to 9 months old. However, a puppy as young as 8 weeks can be neutered if there are no other health problems.
Although it is best to have dogs neutered when they are puppies, they can also be neutered as adults. However, this leads to a slightly increased risk of post-operative complications in overweight older dogs.
Neutering a male dog leads to a decreased risk of conditions such as testicular cancer and prostate problems, as well as a diminished tendency for aggressive behavior, territorial marking and social problems with other dogs.