While male dogs who are neutered do experience an increase in aggressive behaviors right after the procedure, neutering can make them much less aggressive over time. In fact, neutering has bee proven to create a much happier and calmer male dog over time.
Most controlled scientific studies on this question (and there have been many!) show that whether a dog is spayed or neutered has no impact at all on the likelihood that they will be aggressive in any given circumstance.
The safest and most effective way to treat an aggression problem is to implement behavior modification under the guidance of a qualified professional. Modifying a dog's behavior involves rewarding her for good behavior—so you'll likely be more successful if your dog enjoys praise, treats and toys.
While castration does not calm dogs down, it can reduce testosterone-driven actions such as mounting behaviour. It may increase a dog's focus or concentration.
In the end, your dog will still be the same dog that you love, even after it has been neutered. Your dog's personality and energy level are determined by its environment and genetic makeup, not its reproductive hormones. Most often the only changes that you recognize in your pet will be a decrease in negative habits.
The suggested guideline for males is neutering beyond 6 months of age. Given the increased cancer risk for females spayed at a year of age, the suggested guideline is delaying spaying until beyond 2 years of age.
It is widely – and falsely – believed that neutering “calms a dog down”. However, an adult or adolescent dog's basic temperament is relatively independent of testosterone, and neutering won't make any significant changes to his intelligence or personality.
It reduces inter-male aggression but has little effect if the aggression is fear based. If your dog is aggressive in any manner, neutering it is always a good idea. Even if it doesn't help with the aggression, at least he will not pass his or her aggressive genes to any pups he or she may produce.
Benefits of Neutering (males):
Less desire to roam, therefore less likely to be injured in fights or auto accidents. Risk of testicular cancer is eliminated, and decreases incidence of prostate disease. Reduces number of unwanted cats/kittens/dogs/puppies. Decreases aggressive behavior, including dog bites.
Behavioural problems in most cases are reduced or have even disappeared after neutering (male dogs 74%, female dogs 59%). At best, hypersexuality and connected problems are changed as expected. 49 of 80 aggressive male dogs and 25 of 47 female dogs are more gentle after neutering.
Aggression in dogs can be due to guarding territory, resources, or a family member; fear; frustration; prey drive; or pain. In all of these situations, a dog may be pushed too far and can transition quickly from reactive, fearful, or guarding behaviors to being aggressive.
Dog aggression can be related to fear, prey drive, socialization issues, and guarding territory, among other things. Most aggressive behavior in dogs stems from fear and anxiety, rather than the desire to hurt others. A certified animal behaviorist can help you safely deal with your dog's aggressive behavior.
Myth 1: neutering makes dogs calmer
In most cases these dogs are receiving insufficient mental stimulation and/or physical exercise for their age and breed and neutering will not alter this.
According to several studies, the main behaviors that are affected consistently in male dogs following neutering (I guess I am being politically correct now) include: decreased sexual behavior (primarily, mounting behavior), urine marking (depositing urine on objects), and roaming.
Most dogs recover relatively quickly from neutering. A little wooziness is not unusual; post-anesthesia anxiety and fussiness is normal. Young dogs may want to return to play as soon as the same day. However, dogs should be kept calm for 10 to 14 days after surgery, or however long your veterinarian recommends.
Neutering your male dog or cat prevents testicular tumors and may prevent prostate problems. Neutering also decreases the possibility of perianal tumors and hernias, which are commonly observed in older, unaltered dogs.
Behavioral Effects: Desexed males show reduced libido, roaming, conspecific mounting, and urinary marking frequency, as well as reduced male dog-directed aggression in a majority of males desexed for behavioral reasons. There is a detrimental effect on the risk and progression of age-related cognitive dysfunction.
While male dogs who are neutered do experience an increase in aggressive behaviors right after the procedure, neutering can make them much less aggressive over time. In fact, neutering has bee proven to create a much happier and calmer male dog over time.
How old should I desex my male dog? Similarly to female dogs, we recommend that male dogs who will have an adult body weight of up to 20kg be desexed at 6 months old, but that larger breeds are left a little later.
Is it Too Late? The recommended time to spay or neuter a dog is six to nine months. But if your dog is healthy, there is no specific age limit to having the procedure done.
Small dogs do not have as many orthopedic issues, therefore it is fine to neuter them on the younger side at 6-12 months of age. For large dogs that are very prone to orthopedic injury/diseases we now recommend waiting to neuter until 9-18 months of age.
They see another animal or human approaching as a threat. When dogs feel threatened, they either “flight, freeze or fight”. In this case, the “fight” triggers the lunge. These dogs are generally unhappy, and they displace this through aggression or reactive behavior.