Four choices you make for your dog – Choice number two: To neuter or not to neuter?

There are four decisions no dog owner can avoid. You will be making these lifestyle choices for your dog regardless of whether you spend time researching the available information to ensure they are well-considered and informed decisions or whether they are simply choices of omission – we are certainly all prone to taking the easy road of doing things the way we always have.

A few months ago, I wrote about the comprehensive changes in our approach to vaccinating dogs that have led to a situation where routine vaccines will in most cases now be for puppies only as the adult ‘boosters’ of the past are replaced with titre tests.

Today, I want to touch upon another area where changes are currently sweeping across the veterinary community, namely the issue of neutering.

Cultural differences play a big role when new dog owners decide whether to have their dog neutered or to leave him or her intact. In some parts of the world, neutering of healthy dogs is considered unethical. In Norway routine neutering is downright illegal meaning that around 99% of all dogs in Norway are left intact. At the same time, there are parts of the world where neutering has historically been strongly encouraged and perhaps even regarded as a prerequisite for responsible dog ownership.

Until five years ago many vets certainly considered routine neutering as being in the general interest of the dog. The most serious side effect was believed to be the risk of urinary incontinence (‘spay incontinence’) in bitches. Then, in 2013, a bombshell was dropped in the form of a major study from the UC Davis school of veterinary medicine. The study revealed what no one had previously suspected, that neutered dogs of both sexes have a much greater risk of developing joint disease as well as several different types of cancer compared to intact dogs. In the frenzy of studies that have followed, increased risks of allergies, autoimmune disorders and thyroid disease have been added to the list of side effects and though research is ongoing, it is certainly safe to say that this startling new evidence should make anyone think twice before neutering.

For now, here’s what we know:

Male dogs:

Castration

Health benefits and risks

Health benefits of castration

• A castrated dog will have a reduced risk of benign prostate hyperplasia in old age and, of course, no risk of testicular cancer. There are, however, no overriding health-based arguments for routine castration.

Health ill effects of castration

• Increased risk of joint disease (cruciate ligament disease, hip dysplasia and elbow dysplasia)
• Increased risk of several types of cancer (lymphoma, hemangiosarcoma, osteosarcoma, mast cell tumours)
• increased risk of a range of immune-mediated diseases, such as allergies and auto-immune disease

Female dogs:

Bitch spay

Health benefits and risks

Health benefits of spaying

• No risk of pyometra (womb infections)
• Reduced risk of mammary tumours (breast cancer)

Health ill effects of spaying

• Risk of urinary incontinence and increased risk of cystitis
• Increased risk of joint disease (cruciate ligament disease, hip dysplasia and elbow dysplasia)
• Increased risk of several types of cancer (lymphoma, hemangiosarcoma, osteosarcoma, mast cell tumours)
• Increased risk of a range of immune-mediated diseases, such as allergies and auto-immune disease

Please note that the above information relates to routine neutering of healthy dogs only. If your dog has an illness (such as testicular cancer or a womb infection) this may tip the scale in favour of neutering. In the case of healthy dogs, however, it is now clear that neutering will have an overall detrimental effect on the health of male dogs. It also looks like bitches are healthier when left intact, though this requires the carers to look out for signs of mammary tumours and pyometra.

Research is very much ongoing. One aspect, for instance, that it turns out we don’t understand as well as we thought we did prior to 2013 is the relevance of the age of neutering. Whatever new evidence surfaces in the future, there can be no doubt that the way we look out for our dogs is changing fast.