Spaying and Neutering: what you need to know before making the decision

Spaying and neutering your puppy is probably one of the most controversial topics in the dog world.  While there are many health benefits linked to surgically altering your pet (not to mention, completely wiping away the risk of unwanted puppies), there are also many health risks which are typically never addressed with pet owners beforehand.

When you remove a dog’s reproductive organs, you are also removing that dog’s growth hormones. These hormones are absolutely necessary for proper bone growth, muscle development, and maturity.  Spaying or neutering a dog before they have finished growing is called “pediatric sterilization,” and it’s something I highly advise against.
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Pediatric sterilization has been linked to the following issues:

• Affected dogs do not develop normal bone mass and density. This results in smaller bone size, as well as greater incidence of bone cancer, fracture, and hip dysplasia (Torres de la Riva, 2013)
• Increased incidence of reduced bladder control in both males and females resulting from reduced sex hormone levels (Stöcklin-Gautsch, 2007)
• Increased aggression, fearful behavior, and phobias (Farhoody & Zink, 2010)
• Increased risk of acute fatal pancreatitis, diabetes, and obesity (Zink, 2017)
• Increased incidence of infectious disease & autoimmune disorders (Sundburg, 2016)
• Increased risk of developing cancer of the heart and spleen (Torres de la Riva, 2013)
• Increased risk of urinary tract infections (McKenzie, 2010)
• Tripled risk of hypothyroidism (Panciera, 1994)
• Quadrupled risk of prostate cancer (Dressler)
• Decreased cognitive ability (Hart, 2001)

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Development
Since a picture is worth a thousand words, here is one of my favorite infographics. This is a young female Malinois. The photo on the left was taken at the start of her very first heat cycle. Notice how puppy-like she still looks with her narrow face, sunken chest, spindly legs, and “string bean” body type. The photo on the left was taken two days after her first heat cycle ended, and after she had all those growth hormones surging through her body. Notice she has a much broader head and jawline, a thicker neck, more filled out chest, sturdier build with better musculature, and stronger looking bone structure. This is a 23 day difference!

Spaying a dog prior to maturity is just like a child never going through puberty. It drastically affects how they look and develop as they grow. It is my recommendation to always allow a dog to go through at least 2 heat cycles before spaying. Doing so will greatly aid in healthy development.

Hip Dysplasia
This is a diagram which shows the growth of a dog’s hip joints from birth to one year.  This is exactly why dogs need their growth hormones until they are at least one year old.  Many people who do not want to deal with a dog’s heat cycles will opt to spay a dog around 6 months old (around 26 weeks).  Look at how much growing a dog has left to do between 6 months and a year! Notice how at 6 months the growth plate is not sealed yet, the femoral neck is very thin, and there’s still some subluxation of the hip joint. At a year, the growth plate should be sealed, the femoral neck is nice and strong, and the hip is a fully formed and articulating joint.

Here is also a graphic which labels all of a dog’s major growth plates and the time in which they tend to close. For the reasons outlined above, it is not recommended to spay or neuter a dog until all of their growth plates have sealed. While the dog will still GROW, they will not have the necessary hormones to fully DEVELOP. There is a difference.

Highlighted in pink is the first growth plate to seal. Highlighted in yellow is the last to seal (which notice this is a common area for dogs to experience arthritis later in life). ​Please wait until all growth plates have fully sealed before spaying or neutering.  Doing so can mean the difference between a healthy dog for years to come and a dog who experiences arthritis by age 5.
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Urinary Incontinence
While more common in females, urinary incontinence following sterilization affects both male and female dogs.  When a dog is spayed or neutered, it can weaken the bladder (urethral) sphincters, and if a dog is spayed or neutered young enough, it can actually cause developmental urinary tract abnormalities.   
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Aggression, Excitability, & Anxiety
There is a common myth that a spayed or neutered dog will be calmer, less aggressive, animals.  However, recent studies which map behavior traits using specific and easily distinguishable markers have shown the exact opposite.

C-BARQ results from over 10,800 dogs have shown intact dogs (both males and females) actually score LESS on the aggression tests than the dogs who are spayed and neutered.  Results also show that the longer one waits to spay or neuter, the less chance they will have of developing aggression-related behavior problems.
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This doesn’t just hold true with aggression. The same can be found when looking at fear and anxiety scores as well, along with excitability scores.

This study, along with many others, has led scientists to believe that not only does early sterilization affect dogs physically; it affects dogs MENTALLY as well.
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Cognitive Function
A study done by Menjamin L. Hart, DVM, PhD, DACVB analized the effect of gonadectomy on subsequent development of age-related cognitive impairment in dogs among a wide variety of breeds.  The study tracked 4 categories of impairments that senior dogs typically face: disorientation in the home or yard, changes in social interactions with human family members, loss of house training, and changes in the sleep-wake cycle.

It was found that intact dogs were significantly less likely than spayed/neutered dogs to progress from mild cognitive impairment to severe cognitive impairment as they aged from years 11 to 14.  These results suggest that the presence of testosterone and estrogen may in fact slow the progression of age-related behavioral changes linked to cognitive impairment.

The Takeaway
I am not here to tell you what you can and cannot do with your dog. I am not a vet and I am not his owner. However, I can say that based off of my years of researching both sides of the spay & neuter argument, my professional recommendation is to wait until your dog is at least two years old. This will allow for his bones to develop, his joints to seal, his brain to develop, and his body to function like a normal adult dog. This is my recommendation under one condition: BE A RESPONSIBLE PET OWNER.

Being a responsible pet owner means not allowing your unaltered male to roam the streets in search of females, and not allowing your intact female to have unsupervised play time in the backyard when she's in season. You can still prevent accidental litters with intact animals with proper care, training, and management. Let's start with that before we jump to ripping out your dog's organs.