The bone growth plate closure will be delayed if this is done which will then result in taller or bigger dogs. (thebarkbuzz.com)
Sex hormones are what signal growth plates to close, so If your puppy was neutered before around 18 months old, he will have some delay in growth plate closure, and he will also have uneven growth in his bones resulting in joint angles that could be more liable to injury. (americanshihtzuclub.org)
These ages for growth plate closure are only generalities and will vary from puppy to puppy. (americanshihtzuclub.org)