A response to my readers about Dog Parks
by Prescott Breeden

Aggression towards intact Dogs at the Dog Park

I would like to take a moment to respond to some of my readers that have brought an important point to my attention.  In the article titled “Dog parks, friend or foe?” I made the statement, that there should be no intact dogs at the dog park and that “an intact dog is the indicator of an irresponsible or poorly educated owner, and either way they are a major red flag at the dog park”.  One counter argument came from a canine professional that said many of her clients with intact males have “the most solid temperaments I have seen: in and outside the dog park”.  And they are correct, while intact dogs litter the dog bite statistics, they can have just as wonderful temperaments as fixed dogs can and this should not be forgotten.

However, dogs that have been spayed or neutered quite often show aggressive or defensive behavior around intact dogs (primarily male intact dogs).  This comes down in part to a difference in smell (pheromone release) but primarily body language.  Dr. Jim Ha, a Certified Applied Animal Behaviorist and professor at the University of Washington, comments:

“Dogs that are intact tend to have a different body language.  They tend to throw a lot of stricter or stronger social status cues, dominance and subordinate cues, and a lot of times these are not seen, learned or used effectively in dogs that are fixed, so there tends to be a real miscommunication.”

This is wonderfully reflected in a statement that another reader submitted defending their intact dog at the dog park.  “I used to bring my then intact 3 year old male GSD [German Shepherd Dog] to the dog park and other neutered males had an issue with him. My boy is docile and not a fighter”.  What is subtle to some of us, and invisible to most, is that these small differences in body language can lead to some very unhappy campers at the dog park and while an intact dog may not be the dog displaying aggression, his hormones are the cause of it.

To bring back my original point I mentioned in the first article, we cannot forget that they do in fact also litter the bite statistics.  Studies have shown that there is a direct association between testosterone and aggression.(1)  That being said, it is still only one of a number of factors involved in aggression and prior experience and environmental stimuli are other important factors that must be considered.(1)   “Hormones themselves do not directly cause behaviors, but induce chemical changes in certain neurons, affecting the likelihood of certain behavioural outcomes as a result of modulation of particular neural pathway”. (1) This is why you cannot view a case study of a single dog.  When you begin to analyze the data of a few hundred dogs, you start to see that an animal with higher levels of testosterone is the “pocket ace” in a poker game that could change the entire hand.

Further more, the off-leash dog park is not a single’s club, and intact dogs increase chances of unwanted litters.  Assuming that an owner will not bring their intact female to a dog park is naïve.  All unplanned litters of puppies either prevent dogs being adopted from shelters and/or end up in shelters themselves.  This is an unacceptable risk that is causing a constant strain on our shelter system that results in the euthanasia of countless wonderful dogs.

Dr. Ha says frankly, and I am in complete agreement, that “An off-leash dog park that allows any un-fixed dogs is unfathomable.”

For all of these reasons, it is imperative to understand that it is irresponsible to bring an intact dog to an off-leash dog park.  If you have done this in the past, I am not shaking my finger at you or chastising you; I only wish to educate.



1) Simpson, K., 2001, The Role of Testosterone in Aggression, MJM 6: 32-40