Hi, I had my male Bulldozer neutered at 7 months old, I've read it's recommended between 6 and 7 months of age. I also have his sister, they are litter mates, so I had to fix both of them before Blossom went into her 1st heat, as they are in the same house, and I would have had to separate them from each other. It's more important to have a female spayed at an early age, if you are not going to breed her, as the chances of cancer is higher for every heat they go into, especially breast cancer. I fixed her first, and then neutered Dozer a week later. I think it's okay to wait longer for a male, but again if you are not going to use him for Stud, then fixing him is better for his health. Neutering a male lessens the chance of cancers, can calm down the dog, and lessens the dangers of your male running off and getting lost or hit by a car due to chasing female dogs in heat. Some people like to wait until their male is closer to a year old, because they beleive the dogs' head and body will grow bigger before neutering. I don't know if this true or not, or if its just a myth, but maybe someone else on here can give you more I formation on this. I found Dozer changed for the better after he was neutered, he calmed down a lot, wasnt as hyper, he didn't hump us anymore, or his sister, and he became a lot easier to train, as he was more focused, and he also became this snuggley bear.