Best Age to Neuter a Male Dog

The best age to neuter a male dog has changed over the years. We used to think 6 months of age was just right. Turns out this may not have been the best idea, especially for large breed dogs. Historically, 6 months seemed reasonable as pups are done with their puppy shots by then, and they are at a nice, manageable size for surgery. It all seemed to make sense, but now we know a lot more.

Most veterinarians now recommend waiting to neuter male dogs after they reach full skeletal maturity, especially large breed males. Allowing these dogs to grow under the influence of their sex hormones means they grow more naturally, resulting in healthier joint angles and structure. They also grow stronger and less injury-prone tendons and ligaments. We have scientific proof that neutering a dog too early potentially makes him more prone to orthopedic problems like hip dysplasia and torn cruciate ligaments in the knee.

Waiting for skeletal maturity sets up new age recommendations for neutering:

• Small breed dogs: after 12 months of age
• Medium to large breed dogs: after 18 months of age
• Giant breed dogs: after 24 months of age

Some veterinary specialists contend that we shouldn’t neuter male dogs at all. Those of us who still support neutering male dogs are quick to point out the benefits of neutering, including pet population control and the prevention of testicular cancer, prostatic disease, tumors growing on or around the anus (perianal adenomas), and perineal hernias (breakdown of tissue surrounding the rectum). All these diseases are preventable by neutering your dog before he reaches middle age. That said, aggressive, intact male dogs should always be neutered, as testosterone has been linked to aggression. Removing the source of testosterone helps manage this dangerous behavior issue.