Spaying and neutering is a normal process that is performed on pets every year. It is incredibly common for dogs to be fixed by 6 months of age in the US, but in certain countries (such as Germany and Scandinavia) it is considered mutilation and prohibited by law. When I picked up Duke from the animal shelter he was already neutered at 2 months. To me this was normal. When we got our second puppy, we neutered him at around 6 months old. I never stopped to wonder why we fix our dogs at such a young age, until I got my third dog. Recently I had a conversation with a vet at a local pet store about spaying and neutering. I mentioned that I knew many people who were encouraged by their vets to fix their animals as soon as possible, and he said that was because vets wanted to decrease the overpopulation of animals. He told me that early spay and neuter was not necessarily healthier or better for animals; health risks are not necessarily decreased when dogs are fixed early. We as pet owners are encouraged to spay our pets as soon as possible so they don’t contribute to overpopulation, however, we often don’t stop to think about the risks involved.
Dr. Mike Petty says that early spay and neuter has been common practice since he became a veterinarian around 40 years ago. He was told that this would lower mammary tumors by 90%. After Dr. Petty became certified in canine rehabilitation he realized early spay and neuter affects growth plates, leading to orthopedic issues, cancer, and even behavioral issues. A study done on German Shepherds at the UC Davis Vet School found that dogs fixed before they were a year old “triple[d] the risk of one or more joint disorders” and “simply delaying the spay/neuter until the dog is a year old can markedly reduce the chance of a joint disorder.” Although this study was done specifically on German Shepherds, other studies have implicated adverse health issues due to early spay/neuter in other breeds as well.
Behavioral problems were noted as well in dogs that were fixed earlier on, versus unfixed. A study done on German Shepherd bitches around 5-10 months found that the bitches that were spayed were more reactive, (lunging at other dogs, showing overexcitement, dominance, and at times, aggression) versus the ones that were intact. Although this study was specifically done on German Shepherds, it notes that reactivity may be increased in “bitches of any breed generally” and states that a “range of behavioral changes may occur post-ovariohysterectomy.”
The overpopulation of dogs in the United States is a real issue, however, as responsible pet owners it is up to us to keep our dogs under control and do not contribute to overpopulation. If you adopt your dog from the shelter, and you do not want to do a traditional spay or neuter you can opt for a hysterectomy or a vasectomy. This way the dog becomes sterile, but they still produce sex hormones. If you feel that it is the right choice to fix your dog, please make sure to do it after they are fully grown (this will range, especially if you own a large breed dog). Sex hormones play an important part in growth and dogs, like people, need these hormones at such a vital growth stage. Puberty plays an important role in bone growth, so if you fix your dog, I would highly encourage discussing this with your vet, doing more research, and waiting until your dog is full grown (or after 1 heat cycle for a female).