I sell all my puppies on spay and neuter contracts. I don’t allow it t be done until 2 years old. I have not had a problem in the twenty years I have been breeding with anyone breaching my contract.Early neutering of large breed dogs can lead to growth issues. Male dogs of breeds prone to hip dysplasia and other joint problems are often neutered around 2 years old as they do indeed need certain sex hormones to properly fill out.