Clearly today’s topic is sensitive and it will ruffle some feathers… but please hold the hate mail.

It never ceases to amaze me the number of cats and dogs who end up on my surgery table because they were not neutered. Many end up hit by a car. Many end up with a specific type of hernia (more below).

Then there are all the non-surgical reasons, starting with behavior problems.

Are you wondering whether you should neuter your cat or your dog? Here is a non-exhaustive list of 10 reasons to do it.

1. Unwanted pregnancies

Ah… Love at first sight… It’s really difficult for an intact male to resist a female in heat! An intact male classically runs away and can follow the smell of a pretty female in heat located miles away. And keep in mind that one single incident can lead to 4, 8 or 10 puppies or kittens!

Incidentally, you may be liable if your male procreates with somebody’s prized female. Suddenly, the miracle of life has a bittersweet taste, doesn’t it?

2. Pet overpopulation

Meanwhile, 3 to 4 million of unwanted pets are euthanized each year. What a tragedy… This is called “pet overpopulation”.

Many of these deaths could have been avoided by neutering males (and spaying females).

So sterilizing your pet ultimately makes the world a better place.

3. Behavior

Unneutered pets have all kinds of behavioral problems. In male dogs, the most common behavior is an aggressive temper. Of course, there are many intact pets who are perfectly sweet. Neutering, when done early in life, can reduce aggressiveness and improve behavior overall. For example, it decreases the always-awkward “mounting” behavior in dogs.

4. Marking

Few things smell worse than intact male cat urine. Some people make their indoor cat an outdoor cat when they can’t tolerate the smell anymore. This increases the risk of being hit by a car or getting into a fight. Neutering, when done early enough in life, virtually eliminates the odor of male cat urine and should prevent marking in male dogs.

5. Roaming and getting in trouble

Pets are rarely taught how to cross the street safely. So when they roam, searching for trouble or looking for a partner, they might get hit by a car.

In fact, many pets I treat for a fracture are intact. Neutering reduces the urge to roam or run away from home.

In addition, neutering decreases the risk of getting into a fight, especially in tom cats. They commonly get nasty abscesses from these fights.

Family and emergency vets regularly see wounds from dog bites, and I assure you that it’s rarely pretty. I’ve seen many dogs die after getting attacked by another dog.

6. Roaming and getting lost

Every year, millions of pets get lost. Some are returned to their owner. Most are not. To decrease the risk of such a tragedy happening in your family, neuter your pet, pet-proof the fence in your backyard and always keep your pet on a leash during walks.

In addition, talk to your vet about the benefits of tattoos and microchips.

7. Prostate disease

Intact male dogs can have a number of diseases of the prostate including cysts, abscesses and enlargement. The latter is called “benign prostatic hyperplasia,” just as in older men. Neutering (of dogs!) prevents these problems.

8. Perineal hernia

A perineal hernia is a fixable but annoying problem mostly seen in intact male dogs. Organs from the belly can slip or herniate through weakened muscles in the pelvis. The consequence is a bulge on one or both sides of the anus. The hernia can contain fat, fluid or even the bladder. These hernias frequently cause constipation.

This condition is believed to be due to testosterone (from the testicles). Neutering dramatically reduces the risk of these hernias.

9. Testicular tumors

Neutering eliminates the risk of testicular cancer. This condition, mostly seen in intact male dogs, is believed to be due to testosterone (from the testicles). It’s simple, really: no testicles, no testicular cancer.

One more reason to neuter is when a male is cryptorchid, i.e. when a testicle does not come down and remains in the belly. The testicle left in the belly has a much higher risk of becoming cancerous. So this may require 2 surgeries: 1 to remove the “outside” testicle, and 1 in the belly to find and remove the other one. Occasionally, both testicles are in the abdomen.

10. Genetics

Yet another reason to neuter is to prevent spreading bad genes. Pets with hip dysplasia, eye diseases, heart conditions and many other genetic conditions should not be allowed to breed.

It seems, however, that neutering does not decrease, and in fact may increase, the risk of prostate cancer. Luckily, this is a very rare tumor. Therefore, the combined benefits of neutering vastly outweigh the risk of prostate cancer as you can see from this top 10 list.

The next controversy is when to neuter your pet. Again, hold the hate mail: most reasonable vets recommend neutering at 6 months of age.

Phil Zeltzman, DVM, DACVS, CVJ, Fear Free Certified