There are several factors that should make a trainer more
cautious when working with a dog: low sociability, bite history, medical problems, maternal instinct, injuries, barrier frustration, sexually
mature and finally, the topic of this post - sexually intact males. All of these justify more caution. I am always a bit
more careful when working with intact males (higher drive means harder biting). But I still enjoy working with them
hands-on.
Some trainers are wary of working with intact males and will quote a study from a few years ago that showed that intact male dogs between eighteen months and two years of age have a
greater incidence of aggression than females or neutered males. But it's not proven science that this is due to testosterone. It is just as likely that it's due to socioeconomic factors. Dogs who arrive at animal shelters intact are mostly from lower income communities. People who cannot afford to provide medical care certainly cannot afford professional training, and some even encourage aggressive behavior in their dogs in a misplaced effort at "protection training."
In my almost 30 years of dog training experience, I've been bitten more often by neutered dogs than by intact dogs. I know trainers from military and police backgrounds who worked exclusively with intact males and have never been bitten.
Neutered male dogs
have 3 times the risk of hypothyroidism - and there are more dogs who bite due to
hypothyroidism than any other medical factor.
Testosterone doesn’t make a dog vicious, it merely adds
drive. All police patrol dogs and military dogs are intact – and attacks on their
handlers are virtually unheard of.
A landmark scientific study found that only a small percentage of dogs realize a change in
aggressive behavior after being neutered:
Neilson, Eckstein, and Hart,(1997) found that [only] 25%
of adult dogs that were aggressive toward humans or other dogs in the household
can be expected to have a 50 to 90% level of improvement after gonadectomy. A 50 - 90% level of improvement can likewise
be observed in [ONLY] 10 to 15% of dogs that
are aggressive toward unfamiliar people or human territorial intruders after
gonadectomy.
No trainer should get a false sense of security because a
dog is neutered. And no trainer should ever recommend neutering as a solution
to aggression. (Of course, neutered males
who have not yet fought are less likely to fight if they are neutered as a
preventative measure.)
There is universal agreement among breeders of large breed dogs that, for a number of developmental reasons, it is inadvisable to neuter too young, and there are well known health risks involved with spaying and neutering dogs.
Regarding females and any connection between spaying and
aggression, Lindsay’s Encyclopedia of Dog Behavior and Training (Volume 2, p. 187) includes a study
which supports the assertion that incidents of aggression are higher in
spayed females than in non-spayed females.
My main point is this: No trainer should be "more relaxed" just because a dog
is neutered.
