At what age is it best to neuter a male dog?

A male dog’s reproductive organs generally mature around 6 months of age, so the owner can schedule neutering at 6 to 8 months, ideally before the first heat. Neutering has many benefits: it greatly lowers reproductive disease incidence and can extend lifespan.

But neutered dogs easily gain weight, so the owner should adjust the diet promptly; if fed the same as before, the dog is very likely to become overweight.