Why do we spay female dogs and neuter male dogs? Spay/neuter helps produce healthy and good-tempered purebred dogs. Spay/neuter allows a breeder to remove dogs from breeding who should not be bred because some of their puppies and the people who lived with those puppies would suffer. Spay/neuter puts a stop to passing on undesirable genetic traits, while allowing the pup or dog being "culled" from the breeding program to go on and have a great life.

Another significant reason is that spay/neutered dogs do not produce puppies who join the population of unwanted dogs. Spay/neuter is part of the solution to having to put massive numbers of dogs to sleep because there are not enough homes for all of them.

But what's in it for us? What's in it for the dog who is spay/neutered instead of being left intact? What's in it for the family who will live with that dog? After all, you could conceivably keep your intact dog from breeding-though you might be surprised at the difficulty that involves!

But let's say you could do that and didn't mind the inconvenience. Leaving breeding ability aside, why ELSE would you want your dog spay/neutered? Lots of really good reasons exist for doing this. Too often, people stop at the overpopulation reason and never get to the "good stuff" that will matter much more to the average dog and family. Let's talk about the good stuff.

Males

A male dog who remains intact experiences a huge increase in testosterone in adolescence. At several months of age, the male's testosterone level can be several times that of an adult male! This gives a real jump start to hormone-related behaviors, including urine marking in your house, aggression toward other male dogs, territorial aggression, and escape-oriented behavior in order to roam.

Some male dogs, especially tiny terriers and hounds, may be impossible to housetrain if you wait too long to neuter them. With all dogs, be guided by your veterinarian's opinion as to the best time for spay/neuter. Six months to one year of age is usually about the right time.

For best behavioral results, it's best not to wait past a year of age to neuter males. Once a hormone-triggered behavior has continued long enough, you can be dealing with a firmly entrenched habit that will not fade even after neutering. Frequently, neutering helps with behavior problems, even if done much later, so don't give up on it just because you've missed the optimum time.

Intact male dogs tend to have more difficulty concentrating on tasks and to show erratic behavior in the vicinity of a female dog in heat. Intact males may not be able to eat or sleep when a female dog in heat is in the same house! Jumping fences to go after a female down the street is common, even in dogs who have never roamed before.

Your 1-year-old or 2-year-old intact male dog may be acting like a neutered male in terms of being easy to live with, but chances are that if you leave even an easy-going fellow intact to the age of 3 years, you'll see undesirable behaviors. The age of 3 is prime time for an intact male dog to be involved with a terrible tragedy, such as those dogs who have killed children. Obviously, not all intact male dogs are aggressive child-killers. But the risk is increased, and parents need to know this, as does everyone who has a large-breed male dog. If you don't have an important reason for breeding the dog, and the right facilities to keep the dog from harming anyone, why live with this increased risk?

If you want to take your dog out and about, whether for family outings, runs at the dog park, or pursuit of dog sports such as agility, the dog will function better if neutered. Dogs are much more the victims of their own instincts than humans, less able to override impulses.

What is Sex for Dogs?

When dogs mate, they usually tie. This means they are "stuck together" due to the structures of their reproductive organs. The tie tends to last around a half hour. Dogs do sometimes mate without a tie, so the lack of one doesn't mean the encounter can't result in pregnancy. Behaviorally, though, this is quite a different sexual experience than that of humans.

Female dogs invite breeding only when they are in heat/estrus, which comes approximately twice a year. That interval can vary by breed and by individual dog. Dogs often have "silent heats," which can go undetected by their human families and result in the dog not being carefully confined during estrus and therefore winding up with an accidental pregnancy. Female dogs are often forcibly mated. This is surely not natural sexuality.

Looking to the wolf pack, not all members mate. The social structure of the pack and the environmental conditions at the time exert control over which pack members will mate on any given cycle in order to avoid overpopulation and starvation. Usually there will be one litter. If times are bad, there may be no pups at all.

The phenomenon of false pregnancy that is very common in female dogs may be to provide extra parenting for the pack's pups. Female dogs who live together tend to cycle together, putting the non-impregnated females in false pregnancy at the same time the pregnant one has pups in need of nurturing.

Estrus in the wolf pack comes about once a year, but humans have selectively bred dogs to be more productive and thus more profitable to breed. The result is that breeding is not "natural" for dogs. Dogs who are spay/neutered can actually have more active social lives with other dogs than those who are intact. Intact dogs experience stresses that spay/neutered dogs are spared.

People get confused about dogs' sexual attitudes toward humans. For example, a woman having her menstrual period is at the lowest estrogen level of her cycle. Conversely, a female dog in heat is loaded with estrogen. So the scent of a menstruating woman would not be sexually stimulating to a male dog or antagonizing to a female dog. If a dog seems to behave differently when a woman is having her period, it would be for other reasons.

It is wise to give your puppy opportunities to play with a puppy or gentle dog of the opposite sex from time to time when young. Though this play is seldom specifically sexual, it seems to help dogs develop sexual orientation toward other dogs, rather than toward humans, pillows, etc.

Females

Female dogs, like males, have an increased risk of aggression if left intact. Estrus can cause moodiness, and hormone changes in pregnancy can make some females downright aggressive. Her attitude can change overnight. If your dog is going to have contact with children, that's another reason to seriously consider spay/neuter.

With estrus, intact female dogs may show erratic behavior, signs of pain that may be similar to cramping in humans, and a greatly increased propensity to get out of the house or fenced yard. Some dogs stay clean, while others may leave stains around the house. You won't be able to leave her outdoors unsupervised for even a second because the scent of her urine (she will urinate quite frequently) attracts male from a mile or so away.

When a female dog is in heat, both she and the intact males in her vicinity will show changes of behavior, and many of the spay/neutered dogs in the vicinity will, too. It is not fun managing a female dog in estrous.

Many people spay their female dogs after one cycle, because it's so much more difficult than they expected it to be. Many more spay their females after one litter because it's not only more work and more heartbreak than they expected, but it's also much more expensive. Spaying the dog prior to ever getting pregnant can spare both her health and her temperament from sometimes dramatic deterioration. Also, dogs can die attempting to give birth.

Two or more female dogs in the same home will in many cases not be able to get along, especially if one or more of them are intact. Like aggression problems with male dogs, if you wait until the fighting has already begun, fighting may have become a habit that will not be changed with the relief of the hormone pressures when you spay.

Female dogs will sometimes fight each other to the death. That would not be necessary in the wild, where one of them could be driven away to form a new pack. In our homes, it's up to us to manage the dogs so that two incompatible animals are not forced to live together. Spaying dogs before they are fully mature increases the chance of them living together in peace.

Family vs. Career

An intact dog tends to expend a lot of attention and energy in the direction of reproduction. A spay/neutered dog retains the full character of its male or female identity, but has more attention and energy to devote to other things.

What things might a dog do instead of focusing on reproduction? Guide dogs are spay/neutered to help them focus on life aiding blind people. Other assistance dogs to people with disabilities are commonly spay/neutered, too, in part because it helps the dogs focus on work. Certain pups are set aside for breeding future guide dogs when they come from bloodlines of dogs who are serving well in the work and show themselves to be good prospects as they mature.

Since dogs produce litters rather than the single babies and occasional twins born to human, it's not necessary for a huge percentage of dogs to reproduce. Plenty of future dogs can come from the carefully selected dogs who live with people with time and talent to devote to responsible breeding. This is a high calling, and we're all indebted to those people who do it well. They are vital to the future of dogs. If this is what you want to do, find an expert breeder to mentor you, so that you'll be producing from the best of dogs.

Most dogs have careers as companions to humans. Through this labor of love, they enrich and even extend our lives. Spay/neuter makes it easier for us to responsibly care for dogs, and increases the enjoyable activities we and our dogs can do together.

So now you know the behavioral benefits of spay/neuter. When there is no good reason to keep a particular dog intact for breeding, spay/neuter is a great way for you and your dog to live happily ever after.