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Why Neuter Your Dog?

Dr. Lila Miller, D.V.M., ASPCA

  • Male dogs and cats mark territory by spraying urine. This is especially true of cats, whose urine has a very strong odor. Neutering eliminates the odor and markedly reduces the incidence of urine spraying. It is most effective when performed before marking starts, but will often work even after the marking has become a habit.
Why Neuter Your Dog?



  • Neutering eliminates the occurrence of testicular cancer.
  • Neutering markedly reduces the incidence of benign hyperplasia of the prostate gland, prostatitis and perineal hernias in dogs.
  • Male dogs display hormonally influenced aggression toward each other, as do male cats. Neutering eliminates much of this behavior without affecting a male dog’s protective instincts towards his house and family members.
  • Neutering will often decrease or eliminate other objectionable male dog behaviors, such as mounting furniture and family members.
  • Male dogs and cats will cease roaming to find a mate because the hormonal urge to do so has been removed.
  • Neutered animals are not sexually frustrated! Intact animals become sexually frustrated when responsible pet owners do not permit them to mate and satisfy those hormonally driven urges. Without testosterone, these urges are not present and the animals are more likely to focus their attention on their human family rather than on reproduction.

This procedure refers to the removal of the testicles in the male animal. It is a faster, simpler surgical procedure than ovariohysterectomy because the testicles are normally located outside the body in the scrotal sac. Entry into the abdominal cavity is unnecessary in the normal male animal, and the duration of anesthesia is very short. During the early developmental stages of life, the testicles are located in the abdomen. They descend through the inguinal canal into the scrotal sac shortly after birth. Castrations become complicated when the testicles are retained in the abdominal cavity or the inguinal canal, necessitating searching for them. These animals are referred to as cryptorchids or monorchids. Testicles that are not found in the scrotal sac usually do not produce viable sperm, rendering the animal sterile anyway, but they still produce testosterone, which results in objectionable behavior and strong cat urine odors. The retained testicles may also become cancerous later in life, so they should be located and removed whenever possible.

Cat castrations are not performed following the strict sterile techniques of other abdominal surgeries. General anesthesia or heavy sedation is used. The typical cat castration is performed by placing the animal on his back or side, shaving or plucking the hair from the scrotum, wiping the area with a surgical scrub or alcohol, making an incision in the underside or end of each scrotal sac, pulling the testicle out and ligating or tying the spermatic cord and vessels. (The spermatic cord may be tied upon itself as an alternative to ligation.) The incision is usually left open to drain. It can be performed in one to two minutes.

Dog castrations are performed under strict sterile technique and general anesthesia. The dog is placed on his back and a pre-scrotal incision (immediately in front of the scrotum) is most commonly made on the midline and each testicle is pushed forward and removed through that single incision. The spermatic cord containing blood vessels is ligated or tied upon itself. The subcutaneous layer is sutured and the skin incision is either sutured or glued. There are many variations on dog castrations, with some veterinarians performing the procedure the way it is done in cats, but under strict sterile technique. Regardless of the method or age of the patient, castrations in animals with both testicles in their normal position rarely take more than a few minutes.

The most common problems include bleeding, anesthesia-related problems, post-operative swelling of the scrotum (sometimes so severe it may appear that the testicles were not removed) or infection. These complications tend to be annoying but are much less serious than those encountered in spays.

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