I would have him neutered no later than six months. I have operated a non profit Jack Russell Terrier rescue for a little over five years and have seen the over population of America's pets first hand. Not only will you be helping to cut down on the over population problem but your dog's health will benefit from neutering. Also you cut down on the possibility that he will begin to "mark" his territory inside your home. Neutering will cut down his natural instinct to roam looking for any females he may smell that are in season. Neutering will reduce the intensity of any aggressive behaviors he may have. In the future if you have any questions about living with, training, or activities to try with your new Jack Russell, please feel free to contact us again and check out the helpful links on this website.
