Yes, it is very accurate. Most people prefer to wait to have a dog neutered until he is between 18-24 months old. They really need to have the hormones to help them mature physically. A lot of vets recommend neutering around 6 months of age, but that is only because they don't want to risk the dog accidentally impregnating a bitch in heat. When you neuter at a younger age, the dog will usually end up not filling out as much as he would if he wasn't neutered until at least 18 months. Intact dogs usually develop a much broader, blockier head, fuller chest, etc. I firmly believe in waiting until at least 18 months to neuter so that they have plenty of time to mature. The growth plates close around 18 months of age.
