The Spay/Neuter Conundrum (Long version)
Nowadays, traditional spaying and neutering of your dog, also known as altering, is not necessarily the absolute thing to do. Deciding on whether or not to alter and, if so, when, can make a difference in their long-term health. There are options to choose from while still remaining socially responsible by reducing pet over-population! And, just to be semantically correct, both sexes get “neutered” or altered, but the females are “spayed”, which means ovary removal, and the males are “castrated” which means testicle removal. There is so much information on the pros and cons of altering your dog that I simply cannot do it complete justice in this short article. If you simply google the search terms “pros and cons of early spay and neuter”, you’ll find plenty of reading.
Here in North America, a typical “spay” procedure that most of us owning dogs and cats are familiar with consists of a general anesthetic followed by surgical removal of the ovaries and the bulk of the uterus, if not all of it. This leads to a female that no longer cycles, cannot get pregnant, has minimal risk of mammary cancer if done prior to the 3rd or 4th heat cycle, and obviously no longer can get ovarian or uterine cancers.
The traditional approach to castration has been to remove the testes in the males which aids in preventing, without guarantee, potential behavior problems and also prevents certain medical issues related to testosterone in males. As an aside, prostate cancer appears to be more common in the castrated dogs.
As far as ideal age of altering pets, most veterinarians remain on the page that pets should be spayed or castrated prior to going through their puberty and most often will suggest the procedure at or before 6 months of age. Humane societies and SPCA’s are now having puppies and kittens altered prior to being adopted into their new homes, meaning they are often “under the knife” at 8-9 weeks old! There are pros and cons with “fixed” so young, but I will touch on that further on in this article.
It would appear that a one-size-fits-all cookie cutter approach no longer seems to be the best choice for our dogs. For some, yes; for others, decidedly not. What is not well known or well disseminated (yet) is the research done in the last few years analyzing medical records of dogs demonstrating that traditional altering is not always the best approach for every breed.
For what it’s worth, as a holistic veterinarian my recommendations can be summarized as follows and I must emphasize that there is no one magic age if you plan to do this surgery: I most often suggest 7-7.5 months for toy breeds for various reasons, but at times I have recommended allowing them to go through puberty; for medium breeds, I suggest allowing them to go through puberty; and, lastly, I highly recommend waiting until after 14 months minimum for large and 18 months for giant breeds to allow them to reach their genetically pre-determined height. Large and giant breeds that are altered prior to gaining their correct height frequently grow past this height and end up with rather straight hind legs rather than legs with healthy strong angles that judges look for in the show ring. Why does this matter?? Straight legs are weaker and may predispose them to tearing their knee ligament (ACL) which has unfortunately become a very common problem, more common in the dogs altered prior to puberty and prior to growth plate closure. There is also correlation between hip dysplasia and early neutering in dogs.
Here’s where the spay/castrate advice takes a real paradigm shift! When it comes to certain breeds, I suggest leaving them “intact” with their gonads still there. This is called Ovary-Sparing Spay in females and involves removal of the uterus in its entirety at any age and involves a vasectomy in the males at any age if breeding is not wanted. These procedures still allow you to be a “responsible” pet owner by not contributing to the pet over-population, but the evidence is there that you may be helping them out medically for the long haul. Let’s take a closer look at this option further down.
What are the options for the boys?? Well, if you have a very well-behaved male dog that falls into the at-risk breeds, then you can have a vasectomy performed. This will prevent the male from impregnating females should he so happen to go a-wandering without your knowledge! Never a good idea either way. Apparently, studies have shown that the castrated males are the ones with the higher risk of prostate cancer, which flies in the face of what we might think. Not castrating increases the risk of testicular cancer (quite rare), prostate enlargement or infection, and perianal issues like lumps and hernias.
Among the researchers to examine the medical effects of neutering on dogs is Dr. David J. Waters, a comparative oncologist at the Purdue University College of Veterinary Medicine, director of the Center for Exceptional Longevity Studies at the Gerald P. Murphy Cancer Foundation in Indiana and leader of a nationwide research study on aging and healthy longevity in pet dogs.
In a 2009 study, Waters and colleagues studied the impact of sex and sterilization on longevity of Rottweilers. They found that intact female Rottweilers were more likely to achieve “exceptional longevity” than their male counterparts — just as women have a greater chance of living to age 100 than men. But Rottweilers whose ovaries were removed before age 4 lost that female survival advantage. Though the biological mechanism remains unknown, this study indicated a significant relationship between retaining ovaries and longer life spans. This study found an approximately 4-fold increase in the risk of bone cancer in the spayed dogs as one example, which is a problem that seems to be on the rise in our large breed dogs, unfortunately. Many parameters were analyzed and many chronic degenerative medical conditions, including various cancers, were more prevalent in the altered population of Rottweilers.
The second study, that analyzed the medical records of 759 golden retrievers seen at the UC Davis Veterinary Medical Teaching Hospital during a 10-year period, was conducted by a team at the University of California, Davis, and found a greater occurrence of hip dysplasia, cranial cruciate ligament tears and two types of cancer in sterilized golden retrievers compared with their intact counterparts. The research found the health risks generally were greater for dogs that were younger than 1 year when sterilized.
Together, these studies make a compelling case for dog owners to reconsider a complete altering surgery on their dog if they fall into certain breed groups. The breeds that seem to be at high risk include Golden Retrievers, Rottweilers, Bernese Mountain Dogs, German Shepherds, Boxers and others, mostly in the large and giant breed groups.
More and more veterinarians are beginning to take this fairly new research into account in making neuter recommendations for larger breeds. I for one feel that, for certain breeds, the risk of ovarian cancer and mammary tumours in unspayed females or the risk of testicular tumours in intact males are outweighed by the increased risk of so many other cancers and serious medical conditions that exist when you remove the source of sex hormones.
For those inclined to do their own research, in addition to the links above, I offer this link to a paper entitled “Determining the Optimal Age of Gonadectomy of Dogs and Cats” and this link to an article and video describing the partial spay procedure. Here is a link to a review paper that looked at 180 different studies on the effects of neutering and compiled the stats.
As Dr. Karen Becker, a veterinarian writing for www.mercola.com, states: “Your dog should be old enough to be a balanced individual both physically and mentally. This balance isn’t achieved until a dog has reached at least one year of age. Although some breeds reach maturity faster than others, many giant breed dogs are still developing at two years of age.” I concur.
Get some input from reputable breeders and other experienced dog owners, and don’t forget to consult a holistic vet to better understand what steps you can take to ensure the overall health and longevity of your pet.
Dr. Moira Drosdovech
Disclaimer: The opinions in this article are those of the author and it is always prudent to get the advice of your veterinary professional before making any decisions about the health of your pets. Contact us to learn more about our Kelowna veterinarian clinic holistic practices.