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Why is my dog aggressive after being spayed? (Or Neutered)

Why is my dog aggressive after being spayed? (Or Neutered)

So, your puppy is a few weeks old, and you’re starting to ponder the question of spaying or neutering. You don’t know much about the particulars of this procedure, like why people are so adamant about getting it done and what the side effects may be for your dog. You’ve always heard that it’s a good idea for all dogs unless you intend to breed them, but is it?

You know one very basic thing about why people spay or neuter their pets. The main reason people do it is to prevent unwanted puppies from being born when there are too many pets being euthanized already.

However, you have started hearing some pushback from some on social media saying negative things about spaying and neutering. What side effects can your dog have after being spayed or neutered? Let’s see.

Why is my dog aggressive after being spayed or neutered?

For years now, almost every veterinarian in the country has wholeheartedly recommended that everyone spay or neuter their dogs. They go on about the medical, psychological, and behavioral benefits, which included cancer and disease prevention, as well as reduced risk of infection, and earlier studies showed these important things to be true.

As a matter of fact, most dog lovers get their dogs spayed or neutered at the age of 6 to 9 months. A puppy can actually even be spayed or neutered as early as 8 weeks old. Eight weeks is often the age recommended by a professional for neutering a male dog.

However, more recent studies have shown physical and behavioral things happening in dogs that go against this way of thinking. Here are what some of these newer studies found.

Study #1

One study showed that despite conventional wisdom, spaying can be associated with worsened and not improved behavior. In this study, spayed females were found to be more aggressive toward people and more sensitive and fearful of being touched or handled.

Spayed females were found to steal and beg for food more often and be less energetic. They also showed more aggression toward other dogs, barked excessively, and ate and rolled in their own feces. 

Study #2

The common factor between most of the dogs in the second study was that the younger the dog was at the time of his (her) neutering (spaying), the worse the effect it had on his (her) behavior. In the study, it was found that spayed females were less responsive to cues and more anxious, fearful, aggressive, and difficult to train.

Study #3

Yet another study showed that the cognitive skills of a female dog were affected when her ovaries were removed. The speed of accuracy and learning was highest in females who were intact, and the success rate in memory and learning tasks was highest in females who were intact.

Is it common for a dog’s behavior to change after spaying or neutering?

A dog’s behavior can change after being spayed or neutered. They reach sexual maturity at the age of 6 to 12 months. Here are some changes you can look for in your female or male respectively.

Female Changes After Being Spayed

At the age of maturity, female dogs get a surge of estrogen just like humans do when they reach puberty. Their reproduction cycle begins, and thus comes the estrus cycle or “heat”. During heat, she is receptive to males and may breed with them. Dogs “go into” heat twice yearly.

She may stop trying to roam.

Female dogs who are in heat often go out in search of male dogs, so to keep them safe, female dogs who are not spayed should be confined to the inside of your home. If she is in your yard, you should see that she cannot get out, as she could get pregnant, or worse, lost, stolen, or hit by a car. After being spayed, she may stop trying to roam.

Her frequent urination and bloody discharge will end.

A female who is in heat will urinate frequently. This is because during heat her urine draws male dogs to her. She will urinate all over, even on your furniture and carpet. She may also have a bloody discharge during heat. You can eliminate your dog’s frequent urination and bloody discharge by spaying her.

There is much debate regarding whether spaying will help with or worsen her aggression.

Female dogs are sometimes just aggressive, and there are several types of aggression in females. Two major types are possessive or resource guarding and dominance guarding, which you can easily search on Google for more information for clarification on what they are. For years, we have been taught that spaying will help to lessen this aggression in our female dogs, but newer studies are showing us that this may not be the case.

More than one recent study, linked above, has shown that female dogs become more aggressive after being spayed – These dogs can be aggressive toward both people and other dogs. As a whole, these studies show that spaying causes female dogs to become anxious, fearful, less energetic, and difficult to train.

After spaying, they don’t want to be touched or handled, and their cognitive skills are affected. Dogs who were spayed and neutered at a younger age were more adversely affected by the procedure.

Male Changes After Being Spayed

Male dogs undergo changes, too, after neutering. Temporarily, the dog may become anxious, needy, or depressed.

He may become more, and then, less, aggressive over time.

You may also see your male dog become more aggressive immediately after neutering. This tends to subside after about three days, however. After that, some male dogs, over time, start to become less aggressive than they were, to begin with.

This depends on which breed a dog is oftentimes, though, because some dog breeds simply have a propensity toward aggression. Rottweilers are guard dogs, and sadly, American pit bull terriers have been bred to fight. These breeds and others can lean toward aggression naturally.

He may stop marking his territory around your home.

After neutering, your male dog’s habit of sporadically urinating around your home should slow down or come to an end.

He should stop wandering off.

Often, when male dogs wander off, it is because they are being drawn by a female dog in heat. Soon after a male dog is neutered, this should end.

He should stop trying to hump other dogs.

Once a male dog is neutered, he should lose his desire to hump other dogs because his sex drive should taper off.

How long after spaying does a dog behave differently?

After being spayed, dogs usually recover within around 3 days, but both females and males will retain some sexual hormones for as long as 3 weeks, so you will need to keep your dog confined for this period to keep them safe and prevent unwanted pregnancy. 

If your female dog is in her estrus cycle when she is spayed, she may still lure male dogs for this period. For male dogs, they are capable of making a female dog pregnant for up to 6 weeks after neutering. Again, keep your pet confined for these 3 weeks.

How to get my dog to be less aggressive after spaying?

Many, well, most, dogs become aggressive after being spayed or neutered. While many male dogs end up becoming more docile over time, many female dogs remain aggressive. This leaves owners baffled as to what to do to lessen their dog’s aggression. Here is some advice on curbing your dog’s aggression.

Spay your dog early.

Spaying dogs before they reach sexual maturity is one way to prevent aggression. This keeps dogs from experiencing the spikes in hormones at the levels they do when they are left intact. It is much easier to prevent aggressive behaviors than it is to curb them later on.

In older dogs, spaying them may not end aggressive behaviors altogether, but may lessen the number of episodes and possibly the severity.

Seek professional help.

If aggressive behavior persists after spaying, see a veterinary behaviorist or other pet behavioral professional for advice. It could be a matter of lack of training, or it could even be a medical issue.