Canine Neuter FAQ Coulter Animal Hospital in Amarillo, TX

There are several health benefits to neutering. One of the most critical concerns is the prostate gland, which under the influence of testosterone, will gradually enlarge over the course of the dog’s life. In age, it is likely to become uncomfortable, possibly being large enough to interfere with defecation. Under the influence of testosterone, the prostate is also predisposed to infection, which is almost impossible to clear up without neutering. Neutering causes the prostate to shrink into insignificance, thus preventing both prostatitides and the uncomfortable benign hyperplasia (enlargement) that occurs with aging. It is often erroneously held that neutering prevents prostate cancer, but this is not true.

Other health benefits of neutering include preventing certain types of hernias and tumors of the testicles and anus. Excessive preputial discharge is also reduced by neutering.

The only behavior changes that are observed after neutering relates to behaviors influenced by male hormones. Playfulness, friendliness, and socialization with humans are not changed. The behaviors that change are far less desirable. The interest in roaming is eliminated in 90% of neutered dogs. Aggressive behavior against other male dogs is eliminated in 60% of neutered dogs. Urine marking is eliminated in 50% of neutered male dogs. Inappropriate mounting is eliminated in 70% of neutered dogs.

An incision is made, generally just forward from the scrotum. The testicles are removed through this incision. The stalks are tied off and cut. Castration is achieved. If the testicles are not removed, the desirable benefits listed above cannot be realized. The skin incision may or may not have stitches.

The scrotum is often swollen in the first few days after surgery, leading some people to wonder if the procedure was performed. If the dog is immature at the time of neutering, the empty scrotum will flatten out as he grows. If he is mature at the time of neutering, the empty scrotum will remain a flap of skin. Sometimes the incision is mildly bruised. Most male dogs are eager to play by the day after surgery, but to keep the incision intact, it is best to restrict the dog from boisterous activity.

Neutering can be performed at any age over age 8 weeks, provided both testicles have descended. Dogs neutered before puberty (generally age 6 months) tend to grow a bit bigger than dogs neutered after puberty (testosterone is involved in causing bones to stop growing, so without testosterone, the bones stop growing later). The same behavior and prostate health benefits can be realized no matter the dog’s age. (In other words, a dog does not become “too old” to obtain the same health and behavioral benefits of neutering.)

The traditional age for neutering is around 6 months of age, and many veterinarians still recommend neutering at this age.

Activity level and appetite do not change with neutering. A male dog should not gain weight or become less interested in activity post-neuter.

His interest will be reduced, but if he is around a female dog in heat, he will become aroused by her. Mounting behavior often has roots in the expression of dominance and may be expressed by a neutered male in various circumstances that are not motivated by sexuality.

Undescended testicles have an increased tendency to grow tumors. They may also twist on their stalks and cause life-threatening inflammation. For these reasons, neutering is recommended for dogs with undescended testicles. This procedure is more complicated than a routine neuter; the missing testicle can be under the skin along the path it should have descended to the scrotum or inside the abdomen. Some exploration may be needed to find it. Thus, there is often an incision for each testicle. The retained testicle is sterile and underdeveloped. If there is one descended testicle, it will be fertile, but since retaining a testicle is a hereditary trait, it is essential that the male dog not be bred before he is neutered.

In some areas, neutering may be required as municipalities attempt to prevent pet overpopulation. Check with your local city or county officials.