Castrated dog

Have you ever heard that castrated dogs gain more weight, they become lazier and less aggressive? This blog post will talk about castrated dogs and how castration surgery affects their lives, we will also talk about the benefits and what care to take with castrated dogs.

Castrated dog

Castrated dogs no longer reproduce due to surgery that removes the testes in male dogs and the uterus and ovary in female dogs. With the removal of the gonads, these animals begin to produce less sex hormones, which can interfere with the animal’s behavior.

The reduction of testosterone after dog castration makes it calmer, reduces the chances of fights over territory disputes, in addition to reducing the animal’s libido, reducing some reproductive behaviors.

In female dogs, the absence of sex hormones causes them to reduce energy, can increase food consumption and in some studies it is shown that the absence of the hormone progesterone favored the aggressiveness of bitches with other animals, with strangers and even with some tutors.

But what are the great benefits of having a neutered dog?

The great benefits of having a neutered dog are:

  • No heat problems;
  • Minimizes chances of developing some tumors;
  • Reduces the chances of diseases in the genital tract in dogs;
  • Helps in population control;
  • It can help with some behavioral deviations.

Heat problems  

Female dogs in heat can release a bloody secretion, which can make the tutor’s house or apartment very dirty. During estrus, female dogs can also become more active and even try to run away to breed.  

Castrated female dogs, on the other hand, do not go into heat anymore, thus reducing the house dirt with bloody secretions. In addition to reducing the chances of runaways and unwanted compilations.

Tumors 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, a consultation with a veterinarian for spaying is indicated.

In males, castration can prevent the benign prostatic enlargement that affects elderly male dogs. Care must be taken because recent studies show that neutering can bring some harm to dogs. Therefore, castration must be a joint decision between tutors and veterinarians.

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.

In males, testicular diseases such as orchitis, testicular torsion and tumors are no longer a problem since the testicles were removed from the dogs, thus preventing the occurrence of these diseases. 

It is important to remember that cryptorchid dogs have a high chance of developing a tumor in the ectopic testicle, so neutering dogs with this disease is always indicated.

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 offspring 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.

For tutor dogs, it is recommended to consult the veterinarian to assess the need for castration. If it is an animal that runs away a lot, it would be interesting to keep it castrated, avoiding problems with unwanted reproduction.

On the other hand, Molento and colleagues in 2007, show in their research that castration alone is not enough to help with population control. To be a real solution to the uncontrolled dog population problem, a mass castration must be associated with the education of the population for responsible dog care.

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.

Without sex hormones, dogs reduce libido, thus reducing unwanted sexual behaviors, such as mounting behavior on visitors, other dogs and even objects. Territory demarcation also tends to reduce after castration.

Aggression tends to decrease in male dogs, but some female dogs may exhibit more aggressive behavior. However, it can be related to dogs that have already suffered some trauma, or to breeds that are naturally aggressive.

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.


Castrated dogs are dogs that may show a reduction in energy, resulting in decreased physical activity and play. Thus, these dogs may be more prone to obesity when not properly treated. Neutered dogs can reduce the chances of having tumors related to sex hormones in addition to not having some reproductive tract diseases anymore. Finally, having a neutered dog can help reduce the number of abandoned dogs and help control the dog population.

Frequently Asked Questions (FAQs): Castrated dog

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.

How does the castration procedure work?

The castration of the male is called orchiectomy and the removal of the testicles of the animal is done. In this way, there is a suppression of sperm production and the production of hormones such as testosterone.

In females, the surgery is called ovariohysterectomy, where the ovary and uterus are removed. In this way, the suppression of the production of sex hormones such as estrogen and progesterone occur.

Neutered 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.


de la Riva, G. T., Hart, B. L., Farver, T. B., Oberbauer, A.

M., Messam, L. L. M., Willits, N., & Hart, L. A. (2013). Neutering dogs:

effects on joint disorders and cancers in golden retrievers. PloS one, 8(2), e55937.

Hart, B. L., Hart, L. A., Thigpen, A. P., & Willits, N. H. (2016). Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence. Veterinary Medicine and Science, 2(3), 191-19.

Maarschalkerweerd, R. J., Endenburg, N., Kirpensteijn, J., & Knol, B. W. (1997). Influence of orchiectomy on canine behaviour. Veterinary Record, 140(24), 617-619.

McGreevy, P. D., Wilson, B., Starling, M. J., & Serpell, J. A. (2018). Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of desexing. PLoS One, 13(5), e0196284.

McGuire, B. (2019). Effects of gonadectomy on scent-marking behavior of shelter dogs. Journal of Veterinary Behavior, 30, 16-24. 

Molento, C. F. M., Lago, E., & Bond, G. B. (2007). Controle populacional de cães e gatos em dez vilas rurais do Paraná: resultados em médio prazo. Archives of Veterinary Science, 12(3).

Reichler, I. M. (2009). Gonadectomy in cats and dogs: a review of risks and benefits. Reproduction in Domestic Animals, 44, 29-35.

Vanderstichel, R., Forzan, M. J., Perez, G. E., Serpell, J. A., & Garde, E. (2015). Changes in blood testosterone concentrations after surgical and chemical sterilization of male free-roaming dogs in southern Chile. Theriogenology, 83(6), 1021-1027.

Witsberger, T. H., Villamil, J. A., Schultz, L. G., Hahn, A. W., & Cook, J. L. (2008). Prevalence of and risk factors for hip dysplasia and cranial cruciate ligament deficiency in dogs. Journal of the American Veterinary Medical Association, 232(12), 1818-1824.

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