Castration of dogs and cats: benefits and considerations

The decision to castrate a dog or cat is one of the most significant that a tutor can make, directly impacting the health, behavior and quality of life of the animal for many years. It is a choice that, although routine in veterinary medicine, still generates many doubts, myths and fears. This article, prepared by an experienced specialist, aims to be a definitive guide, offering concrete and evidence-based information to help the Brazilian reader to make the best decision for his companion.

It is not just about avoiding unwanted litters, but an investment in longevity and well-being. Understanding the benefits and considerations involved is crucial for responsible guardianship.

Why Castrate? Undisputed Benefits for Health and Well-Being

Castration, whether ovariohysterectomy (removal of ovaries and uterus) in females or orchiectomy (removal of testicles) in males, is a procedure that goes far beyond population control.

For Females (Cads and Cats)

• Prevention of Serious Reproductive Diseases: Castration completely eliminates the risk of pyometra (severe and potentially fatal uterine infection affecting unneutered females, especially after 5 years of age). It also prevents uterine and ovarian tumors, which are aggressive and difficult to treat.
• Significant Reduction of Breast Tumors: Castration before first heat reduces the risk of developing breast tumors in bitches and cats by up to 99%. With each subsequent heat, the risk increases. Breast tumors in animals are often malignant and require complex surgeries and often chemotherapy.
• Elimination of Oestrus and Its Inconvenients: Unneutered females enter heat periodically (two to three times a year in bitches, and every 21 days in cats if they do not mate). This period is stressful for the animal and the guardian, with bleeding, excessive vocalizations, behavioral changes and the attraction of unwanted males.
• Prevention of Pseudocyesis (Psychological Pregnancy): Some unneutered females may experience pregnancy symptoms (breast enlargement, milk production, nest building) without being pregnant, which causes discomfort and can lead to breast problems.

For Males (Dogs and Cats)

• Prevention of Testicular Tumors: Removing the testicles eliminates the risk of testicular cancer. This benefit is particularly important for animals with undescended testicles (cryptorchidism), which have a significantly higher risk of developing tumors.
• Reduction of Prostatic Diseases: Castration dramatically reduces the incidence of benign prostatic hyperplasia (enlargement of the prostate gland, common in unneutered elderly dogs, causing difficulties in urinating and defecating) and perianal adenoma.It also decreases the risk of prostatitis (inflammation of the prostate).
• Behavioral Improvement: Castration can mitigate unwanted hormone-related behaviors such as territorial urine marking (especially in cats), inter-male aggression, escapes to seek females in heat and excessive vocalizations.This contributes to a more harmonious coexistence and reduces the risk of traffic accidents or fights.

Additional Benefit: Population Control and Social Welfare

Castration is the most effective tool to combat the overpopulation of street animals. Millions of dogs and cats are abandoned annually in Brazil, and the vast majority of litters are born from homeless animals or from guardians who cannot find responsible homes for all puppies.By spaying your pet, you directly contribute to reducing animal suffering and pressure on shelters and NGOs.

Beyond Health: Behavioral Impacts and the Weight Question

While health benefits are paramount, castration can also influence your pet's behavior and metabolism.It is critical to understand these changes to manage expectations and adapt care.

Behavioral Change: What to Expect

Importantly, castration is not a magical”“ cure for all behavioral problems.It primarily acts on behaviors that have a strong hormonal basis.

• Reduction of Escape Behaviors: Unneutered males have a very strong instinct to seek females in heat, which leads them to flee and expose themselves to dangers such as roadkill or fights.
• Decreased Territorial Marking: In dogs and especially in male cats, castration significantly reduces or eliminates the habit of urinating to mark territory.
• Less Hormone-Directed Aggression: In males, castration can reduce aggression with other males, especially if performed early.However, aggressions that stem from fear, inappropriate socialization or training problems will not be resolved only with castration.
• Calmest and Focused Pet: Neutered animals tend to be less anxious and more focused on their families as they are not constantly under the reproductive impulse.

Important Consideration: A playful animal will remain playful, and a shy animal will remain more reserved. Castration modulates instincts, not essence. Behavior problems that persist after castration should be evaluated by a behaviorist veterinarian or qualified trainer.

Post-Castration Weight Management

A common concern is weight gain after castration.It is true that neutered animals tend to have a slower metabolism and a lower caloric need. This is because the body no longer needs to expend energy for reproductive processes and hormone production.

However, castration itself does not fatten the animal. Weight gain is the result of a simple equation: caloric intake > caloric expenditureif the diet and activity level are not adjusted, the neutered animal will gain weight.

Strategies to Avoid Weight Gain:

• Adapt the Diet: Opt for specific diets for castrated animals, which are formulated with fewer calories and more fiber to promote satiety. If it is not possible, reduce the amount of the usual feed.
• Strict Portion Control: Weigh the feed according to the manufacturer's recommendations and the activity level of your pet. Avoid leaving food at ease.
• Stimulation to Physical Activity: Keep a regular exercise routine.Walking, play and environmental enrichment are key to maintaining the ideal weight and mental health of your pet.
• Avoid Excessive Snacks: Snacks are high in calories. Use them sparingly and prefer healthy options.

The Right Time: Age and Other Important Considerations

Choosing the optimal age for castration is a decision that should be made in conjunction with your veterinarian, as there are nuances depending on the species, breed and size of the animal.

Dogs

• Small and Medium Breeds: Generally, castration is recommended between 5 and 6 months of age, before or shortly after the first heat for females. For males, before developing territorial marking behaviors or sexual aggressiveness.
• Large and Giant Breeds: Some studies suggest that postponing castration in males and females of large/giant breeds (to 12-18 months or until the end of growth) may be associated with a lower risk of certain orthopedic diseases (such as hip and elbow dysplasia) and some cancers (such as osteosarcoma), due to the role of sex hormones in bone development.However, postponing castration increases the risks of pyometra and mammary tumors in females, and testicular tumors/prostatic diseases in males.

C decision criterion: For large breeds, the guardian should talk openly with the veterinarian, weighing the risks and benefits for their specific animal, considering their lifestyle, temperament and racial predisposition to certain diseases. The risk of pyometra in non-castrated females is real and serious. The risk of a testicular tumor in a cryptorchid is high and unquestionable. The orthopedic risks and some cancers in large breeds castrated early are percentage low compared to the general population and often outweighed by the reproductive and behavioral benefits.

Cats

• Recommended Age: For cats, castration is usually recommended between 4 and 6 months of age, before sexual maturity.Cats can enter heat from 4 months, and males begin to mark territory and flee early.
• Early Castration (Early-age Neutering): In some population control programs or shelters, castration can be performed on puppies from 8 weeks of age, provided they reach a minimum weight and are healthy. Studies show that it is a safe procedure with rapid recovery, without long-term adverse effects when performed by experienced professionals.

Essential Pre-Surgical Checklist

Regardless of age, some steps are non-negotiable before surgery:

• Detailed Veterinary Consultation: The veterinarian will evaluate the animal's health history, perform a complete physical examination, and discuss the surgical and anesthetic plan.
• Pre-Anesthetic Exams: Blood tests (hemogram, kidney and liver function) are crucial to assess the overall health of the animal and identify any anesthetic risks.In older animals or those with a medical history, additional tests such as ultrasound or electrocardiogram may be needed.
• Vaccination and Deworming on Day: The animal should be in good health for the procedure.
• Fasting: Clear instructions on fasting water and food will be provided by the veterinarian. Failure to comply can lead to serious complications during anesthesia.

The Surgical Process and Recovery: What to Look At

Castration surgery is a relatively quick and safe procedure, but postoperative recovery requires attention and care to ensure the welfare of the animal.

The Surgery

The animal will be sedated, intubated and kept under inhalation anesthesia, which is safer and allows precise control.Heart, respiratory and blood pressure monitors are used.The procedure is performed with strict sterile techniques.

• Females (Ovariohysterectomy): An abdominal incision is made to remove ovaries and uterus.
• Males (Orchiectomy): The incision is smaller, usually in the prescrotal region, to remove the testicles.In cases of cryptorchidism, the incision may be abdominal.

At the end, the incision is sutured, and the animal is given pain medication and anti-inflammatory drugs.

Postoperative Recovery: What to Expect and How to Care

The first 7 to 14 days are crucial for recovery.

• Medication: Strictly follow the schedule of pain medication and anti-inflammatory prescribed by the veterinarian.The post-surgical pain is real and needs to be controlled for the comfort of the pet.
• Incision Protection: The use of Elizabethan collar (cone) or surgical clothing is COMPULSORYanimals tend to lick, bite, or scratch the incision, which can lead to stitches, infection, or wound opening (dehiscence). Do not remove the protection, even for feeding, unless instructed by the veterinarian.
• Physical Activity Restriction: The animal should remain at rest. Avoid jumps, runs, sudden games and stairs. Walks should be short and with a leash, just for physiological needs. The ideal is to keep the pet in a calm and supervised environment.
• Incision Observation:
  • Normal: Small redness around the spots, mild swelling in the first few days. A small clear discharge may be normal.
  • Warning Signs (Contact Veterinarian Immediately): Active bleeding, yellowish or greenish discharge (pus), excessive or progressive swelling, strong odor, opening of stitches or incision.
• Appetite and Elimination: It is normal for the appetite to decrease slightly in the first 24 hours.Make sure that the animal is eating and drinking water normally and that it is urinating and defecating.
• Veterinary Review: Schedule a return with the veterinarian for the removal of stitches (if they are not absorbable) and a general evaluation of healing.

Common Errors in Recovery

• Remove Elizabethan collar/surgical clothing: Believe me, your pet does not like the cone, but it is your best protection. Remove ahead of time is the most frequent and dangerous mistake.
• Allow excessive activities: An animal that looks “normal” does not mean it is completely healed internally. Overdoing it in play can cause internal bleeding or dehiscence.
• Do not administer pain medication: Pain is not “frescura” Animals feel pain and medication is essential for a calm and stress-free recovery.
• Not observing the incision: Monitoring healing daily is crucial to identifying problems early.

Caring for the Castrated Animal: Adaptations on a Day-to-Day basis

After surgical recovery, the life of your neutered pet continues with some minor adaptations that will ensure its long-term health.

• Adjusted Nutrition: As mentioned, the metabolism of the castrated animal is slower. The transition to a “light” or specific feed for castrated animals is fundamental. These feeds are formulated with lower caloric density and higher fiber content to promote satiety. Follow the guidelines of the veterinarian or the feed manufacturer for the daily amount, adjusting according to the activity and weight of your pet.
• Regular and Adequate Exercise: The importance of physical activity increases after castration to maintain healthy weight and stimulate mental well-being. Dogs need daily walks and interactive play. Cats benefit from toys that stimulate hunting, scratching and play sessions with the tutor.
• Periodic Veterinary Check-ups: Even neutered dogs and cats need regular visits to the vet for annual check-ups, vaccination, deworming and routine check-ups.This allows for early detection of any health problems that may arise.
• Continuous Observation: Keep an eye out for any changes in behavior, appetite or weight. Deep knowledge of your pet is the best tool to identify that something is not right.

Frequently Asked Questions

We compile the most common doubts of tutors about castration:

Will my pet become sad or depressed after castrating?

No. Animals do not have the same concept of sexuality or having puppies as humans. Castration does not cause sadness or depression. On the contrary, many animals become calmer, less anxious and more focused on interacting with the family, as they are no longer under the stress of reproductive and hormonal impulses. Any significant mood change should be evaluated by a veterinarian.

Will my pet's personality change completely?He will lose the “essence”?

The fundamental personality of your animal (if it is extroverted, shy, playful) will not change. What castration can change are behaviors that are strongly influenced by sex hormones, such as the instinct to escape in males, territorial marking or inter-male aggressiveness.

Is surgery dangerous?

Like any surgical procedure involving anesthesia, castration has risks, but they are generally very low in modern veterinary medicine.With proper preanesthetic examinations, safe anesthetic protocols, constant monitoring during surgery, and an experienced surgeon, complications are rare.The health and behavioral benefits of castration often far outweigh the small surgical risks, especially when compared to the risks of diseases such as pyometra or breast tumors.

Is castrating too expensive?

The cost of castration can vary considerably depending on the veterinary clinic, the region, the weight of the animal, the pre-anesthetic examinations included and the type of anesthesia. It is an investment, but it should be seen as a preventive expense. Compare this cost with the treatment of a pyometra (complex and expensive emergency surgery), the treatment of a breast cancer, or the costs associated with unwanted litters (feeding, vaccination, deworming of puppies). In addition, many municipalities in Brazil and NGOs offer social castration programs with subsidized or free costs, making access more democratic.

Castration is undoubtedly one of the greatest acts of love and responsibility you can offer your dog or cat. By making this informed decision and together with your trusted veterinarian, you not only contribute to the health and well-being of your own animal, but also to public health and control of the population of street animals.