They will still be as protective of their territory as they were before surgey. Neutering makes pets fat. Neutering does not make your pet fat or lazy. Too much food and not enough exercise is the main cause of obesity. Neutering will hurt him.
Neutering is a safe and relatively painless operation done by a licensed veterinarian.
Your pet will appreciate the freedom from sexual frustration. Spaying will make my pet fat. Spaying your pet will not make her fat and lazy. Too much food and not enough exercise is the main cause of obesity. She should have one litter first.