Female dog aggression after spaying

Can a castrated dog be less aggressive? Does this also work for female dogs? Recently, some studies have shown that castration often does not bring the results expected by many tutors. In this blog post we will talk about the dogs aggressive behavior and if this type of behavior can be reduced after spaying female dogs.

Female dog aggression after spaying

Castration in male dogs is usually done to reduce the dog’s aggression. In females, on the other hand, it can happen that some animals become more aggressive, with strangers, other animals or even with their tutors.

Some female dogs may become more aggressive after spaying. The reason for this increase in aggregation is not yet very well defined. But dogs that already have a predisposition to be aggressive, can worsen the aggression after spaying.

Some studies show that the castration of a female dog after heat, or in the period called diestrus, leads female dogs to be more aggressive. It is believed that castration in diestrus causes a sudden hormonal variation that can lead to aggressiveness.

What is canine aggression?

Aggression in dogs is characterized by the act of barking, blushing or even biting other people or dogs. It can happen for a variety of reasons such as

  • Breed genetics;
  • Tutor training;
  • Trauma;
  • Human stimulation.

Breed genetics

Some breeds are more predisposed to be aggressive. They were even selected to be hunters or even fight dogs. Breeds such as American Bulldog, Rottweiler, German Shepherd dog, and others, can be very aggressive towards strangers and even other animals.

Tutor training

Dogs wrongly trained by tutors can lead to dog aggression. Negative stimuli generate fear, anxiety and trauma in dogs can make them react negatively, thus encouraging them to be more aggressive.

When a female dog is already aggressive before neutering, she is predisposed to become more aggressive after the surgical procedure. The dog can be aggressive with tutors, strangers and even other animals.


Traumas are disturbances that can be physical or psychological that are marked in the dog’s life. Trauma is common in abandoned dogs, or domesticated dogs that are mistreated by their tutors.

Some actions and sounds made by humans can stimulate trauma in dogs, and in response the dogs become more aggressive as a form of defense for the animal itself.

Human stimulation

Some breeds are selected for guarding and protecting homes, so it is ideal that these animals be more aggressive. For these tutors more aggressive dogs with strangers are ideal. So, these dogs are trained to react aggressively to certain situations.

These dogs play a very important role in public defense, as they can be used as work dogs for police and firefighters, helping not only in human protection but with their sense of detecting drugs at airports or locating victims in some accidents.

Why is castration indicated to female dogs?

For some animals, spaying can help reduce dogs aggression, but in addition, to the female dog castration can have other great benefits such as:

  • Population control;
  • Prevention of breast tumor cases;
  • Prevention of genital tract diseases;
  • Behavioral changes.

Population control

Castrated dogs do not reproduce, thus helping with population control. Abandoned dogs can benefit more from this practice, while tutor dogs will never reproduce even if they are not castrated, requiring an evaluation with the veterinarian to make the best decision for the animal’s health.

Population control is very necessary due to the large number of abandoned dogs. Abandoned dogs without castration can generate many puppies and thus only exacerbating the problem by increasing the population of abandoned dogs. That’s why it’s important to perform castration, especially in abandoned dogs.

Tumor prevention

In female dogs, spaying can reduce the chances of breast tumors. Some breeds, especially small breeds, are more predisposed to develop breast tumors. For these breeds, consultation with a veterinarian for sparing is indicated.

Prevention of genital tract diseases

In female dogs, diseases such as pyometra, endometritis, uterine tumors, ovarian cysts and others are no longer a concern. In the surgery, the uterus and ovaries are removed, so the animal will not have any of these diseases.

 Behavioral changes

Behavioral changes

Castrated dogs tend to be less energetic so they reduce physical activity and play. But not all dogs are like that, some continue to show active behavior.

Therefore, after castration, the use of food for neutered dogs is indicated, thus avoiding the animal’s weight gain associated with the reduction of physical activities.

Dog behavior can be learned at the puppy stage and even at puberty. These learned behaviors can remain even after castration. Castration can reduce some behaviors in some dogs and even solve unwanted problems, but castration is not a sure solution to dogs behavior problems.


With this article we were able to understand that neutered female dogs can become more aggressive. The causes are still not very well defined, but several causes such as genetics, trauma and tutor training can influence the aggressive behavior of female dogs. Finally, we discussed a little about the benefits of castration.

Frequently Asked Questions (FAQs): Female dog aggression after spaying

Spayed female dog comes into heat?

No, this is because castration removes the internal reproductive organs responsible for inducing heat. In this way, it is not possible for a castrated female dog to show heat. If the female dog is in heat a possible disease called remnant ovarian syndrome should be investigated.

Can a neutered dog still be attracted to an unneutered dog?

Yes, dogs can be attracted by the pheromones exhaled by unneutered dogs. But this does not indicate that there may be copulation between them.

What are the benefits of spaying a female dog?

The benefits of spaying a female dog are:

  • Population control;
  • Prevention of breast tumor cases;
  • Prevention of reproductive system pathologies such as pyometra, endometritis, among others;
  • Behavior change.


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