We neuter dogs by surgically removing their testicles. By removing the source of hormones, it has several benefits but also some risks (just like everything in life).
WHAT ARE THE BENEFITS? 1. Population control: I know we all LOVE puppies but there are so many amazing rescue puppies that need their fur-ever families Saving Grace Animal Society and Old MacDonald Kennels & Animal Services 2. Prevent reproduction: we also need to consider the transfer of sexually transmitted diseases that can be difficult to treat. Luckily, in Canada, we see a low prevalence of these diseases. 3. Cancer: testicles are the 2nd most common place for cancer in intact male dogs. Testicles that do not drop into the scrotum (cryptorchid) are at an even higher risk of cancer. 4. Prostate disease: the incidence of prostate disease increases with age in intact male dogs. In dogs over 7 years old, prostate disease is noted in >60% of intact males. Prostate disease is very rare in neutered dogs and is effectively prevented and treated with neutering. 5. Behavioural benefits: aggression, inappropriate elimination (feces, urine), roaming behaviour, and/or fearful behaviours. These male behavioural traits can be started because of hormonal influence but can eventually become learnt behaviours if left intact long enough. This means, that even with neutering, it may be more difficult to get rid of these undesirable behaviours.
WHAT ARE THE RISKS? 1. Surgical risks: like any surgery, there are always risks with anesthesia. Risks decrease when we know more about what is going on inside your pet. This is why many clinics will offer pre-anesthetic bloodwork prior to neutering. 2. Cranial cruciate ligament (or ACL) tear: it has been shown to be more common in dogs neutered before 6 months of age because the angle of their bones in their ‘knee’ (stifle) are different than those neutered later. 3. Obesity: once neutered, pets need less calories per day and if fed the same or free fed they may become obese. Obesity will predispose your pet to many diseases.
WHAT ARE THE UNKNOWNS? 1. Risk of prostate cancer: some studies have showed an increased risk with neutering while some have shown decreased. We need more research in this area before we can come to a conclusion. 2. Risk of bone cancer (osteosarcoma): one study reported that neutering before sexual maturity may increase the rate of bone cancer. But, the neutered animals in the study lived longer than the intact animals which may have contributed to the increased incidence.
WHAT AGE SHOULD I NEUTER MY DOG? There is no clear scientific basis for picking a perfect age, so we need to weigh the pros and cons to try to figure out the ideal time to neuter your pet. For small to medium size dogs, I typically recommend around 6-8 months of age. This is because pets are close to done growing (so proper bone growth), are better equipped to handle anesthesia, and are usually have not learnt negative behaviour traits. Giant breed dogs have other factors we need to consider as well. Once I do more research and get my facts organized, Ill write a post on giant breed dogs and why it is recommended to wait a little bit longer.
The world of veterinary medicine is constantly changing as we gain new information about the benefits and risks of neutering dogs. Some of the studies in which these conclusions have been drawn have limitations because often we are unable to do large scale, controlled, blinded studies on pets. Instead, many of the studies on the effects of neutering dogs look back on a pets life (retrospective observational) rather than controlling for all variables (food, environment, obesity, etc.) throughout pets life. So, we have to recognize that other factors could be contributing or causing the increased or decreased likelihood of certain diseases.
Talk to your vet about more information about neutering your dog.