Spaying or Neutering Your Pet

The following is an article by Jean Petersen from Canine Consultants. Jean goes into great depth comparing and contrasting the lifestyles of altered or unaltered pets. The article is long but good, take a look through it.

Should I Spay or Neuter My Dog?

By Jean D. Petersen, c1995

(This article may be reproduced by any dog-related organization, as long as the intent is education of the membership or the general public, the content is reproduced in its entirety, and proper credit is given. Any other use will be in violation of copyright.)

Special thanks to Frances O. Smith-Wilton, DVM, PhD, (board certified specialist in small animal reproduction) for reviewing this paper for technical accuracy and for sharing the most current information on the subject.

Why Should I Think About This?

Spaying and neutering (also called "altering") are surgical procedures with the primary purpose of preventing the individual dog from reproducing. We all hear continually about the millions of puppies and adult dogs which have to be euthanized because there just aren't enough homes for them all. Many of the dogs that do find homes have serious genetic physical and/or temperament problems because the owners of the parent dogs didn't realize that such things could be passed on or were unaware that their animal was a carrier of undesirable genetic traits.

There are some other good reasons for altering your family dog that I'd like to tell you about.

What Can I Expect From My Dog If It Is Not Altered?

The onset of puberty (beginning the process of sexual development) in the domestic dog is about 14 weeks of age (3 ½ months)! That's when they still look like sweet little puppies, but in reality they are becoming teenagers. The period of adolescence lasts until about age 1 year for small breeds (toys, such as chihuahuas, yorkies, etc.), about two years for medium-sized dogs (labs, guldens, German shepherds, etc.), and three years for giant breeds (newfoundlands, saint bernards, great danes, etc.) During the period of adolescence, dogs go through behavior changes caused by their increasing levels of the sex hormones. There are also physical consequences for the unaltered dog.

The Life Of The Unaltered (Intact) Male Dog

Once the male puppy has entered into puberty, his testosterone level increases to 2-3 times what it will be after he becomes physically mature. This high level of testosterone stimulates the physical development of his body's secondary sexual characteristics - - broader head, thicker neck, broader shoulders, heavier lip folds - - that make him look definitely masculine. It also stimulates more dominant or even aggressive behavior. He will start challenging the authority of the other members of the "pack" he lives with (your family), trying to improves his status in the pack hierarchy (order of authority). If he is strongly dominant genetically, this challenging process can results in serious aggressive behavior to your kids, their friends, and even the adults in your family or visiting your home.

The intact male also expresses more aggressive behavior to other dogs, particularly other males. If he is larger than the other male, the other might be seriously injured or killed. If he is smaller, HE might be the one to be injured or killed! Dogs have no sense of size - - they don't see the other dog as larger or smaller, just as another dog to be dominated or run out of their territory.

Another testosterone-mediated behavior is urine marking (often in the house), by which the dog puts his own scent on anything he considers his - - his yard, his path for dog walks, his house, sometimes even his own pack members! Even when this dog is good about not marking in his family's own house, he will not always carry that behavior into someone else's house, especially if another dog lives there. Marking behavior is different in his mind from eliminating because of the physical need to empty. Being housetrained, in his mind, means he doesn't eliminate in his pack's house. But marking is a different process all together.

And finally, there is his behavior whenever he can smell the scent of a female dog in "heat". This scent can be perceived over a large territory, as far as 3 or 4 miles, if the wind is right! Whenever the intact male is so stimulated, he loses interest in everything except getting to that female and breeding her. If prevented from getting to her, he will often go off his feed, howl or bark intensely, and possibly become destructive in his attempt to get out and find her. This behavior will last as long as he is being stimulated by her scent, which can go on for two to three weeks. If he does get out, he will most likely encounter other males similarly stimulated, and dogfights will inevitably ensue. Maybe your dog will win, and maybe he won't. In any case, he will probably be seriously injured. There's also the possibility of getting hit by a car on the way to the female's house.

Once a male dog has been successful at breeding a female, his testosterone-mediated behaviors often become more intense.

Physical Problems In The Intact Male Dog

Retained testicles - - A male dog is born with his testicles inside the abdominal cavity. They normally descend into the scrotum any time between 5-8 weeks and 10-12 weeks of age. Sometimes one or both testicles do not descend, but remain in the abdominal cavity. A retained testicle cannot produce viable sperm, but it does continue to produce testosterone. Retained testicles are subject o a fairly high incidence of Sertoli cell tumors, with a lower incidence found in scrotal testicles. Sertoli cell tumors in on testicle often occur with atrophy in the other testicle, resulting in feminization due to imbalance of hormones.

Benign Prostatic Hyperplasia (BPH) - - the dog is, along with the human male, subject to this noncancerous enlargement of the prostate gland, which can results in severe interference of passing stool from the colon to the outside. The colon can become impacted and painful. If the passage of stool is completely cut off, the dog is severely at risk and requires emergency surgery. Castration is necessary to reverse the enlargement.

Other tumors of the testicles - - there are other types of tumors, both malignant and benign, that occur, especially in the older dog.

Life After Neutering

Neutering can be done at any point in the dog's life, but those surgeries performed on the older dog are often the response to a serious medical condition. In this situation, the surgery is often complicated by other health problems. A better results can be obtained by neutering when the animal is young and in good health. Usually, it is recommended to neuter a dog just before it starts exhibiting testosterone-mediated behaviors, at about 6 months of age. There is currently research going on regarding the very early neutering of puppies, before 7 or 8 weeks of age. Because the sex hormones are also involved in other developmental processes, researchers are following the dogs to see if there are any longer term effects as the dogs go through their complete life span.

If both testicles are descended, neutering is minor surgery, and the dog recuperates very quickly. If one or both are retained, then the surgery is comparable to the spay for the female. Recuperation is still quick. It will take a while for the level of testosterone in the blood to decrease, so those behaviors strongly motivated by testosterone won't show abrupt change. But within a few days to a few weeks, testosterone-mediated behaviors decline. Neutering does not change the dog's behavior or attitude toward people, except for lessening testosterone-mediated aggression. But it will definitely calm down the dog's behavior towards other dogs.

If the dog is neutered before acquiring the secondary sexual characteristics, he will not develop the full male physical changes, but will not look like a female! He will instead undergo a slower development, with somewhat diminished secondary sexual characteristics. He is neutered after reaching both sexual and physical maturity, his looks will not change.

The two great benefits of neutering to the dog are: 1) having the possibility removed of acquiring the tumors and other testosterone stimulated conditions such as BPH; and 2) not having to respond to the sexual stimulation of females in heat, a very stressful situation!

The Life Of The Unaltered (Intact) Female Dog (Bitch)

Once the female puppy has entered into puberty, her estrogen level rises and her body begins preparation for her first heat (estrus) cycle, which will come sometime between 6 and 12 months of age (occasionally later), and then every 4 to 9 months, with the average being every 6 months. At her first heat, she will still be actively growing, and although capable of becoming pregnant, a pregnancy would strongly compromise both her health and that of the pups. She also would not be sufficiently mature to have available the proper nurturing and care-taking behaviors. She should not be allowed to become pregnant until she has reached full physical maturity, at two to three years of age.

The first pregnancy, even for a mature bitch, can be very risky - - a maiden bitch has about a 50% chance of serious complications in delivering her first litter. Common complications are: insufficient level of hormones to stimulate delivery, a puppy that is too big and gets stuck, a dead puppy that won't move - - all these require emergency caesarian section delivery, which is also risky for the bitch. Later complications can include lack of sufficient hormones to expel all placental material or let down milk, calcium insufficiency to produce milk and take care of the mother's needs simultaneously (an emergency situation), uterine infection (which could necessitate an emergency spay), or mastitis, which would prevent the mother from nursing the newborn pups. That would mean you would have to feed the pups - - every 2 hours, day and night, and after each feeding stimulate them to eliminate and clean them up afterward.

If she doesn't become pregnant, the bitch goes through a pregnant hormone cycle anyways, causing a "false pregnancy", during which she can exhibit all the behavioral changes found with a true pregnancy. In some bitches, physical changes are also seen, such as mammary development and even lactation.

In the two or three weeks preceding a normal heat cycle, the bitch can become irritable with other dogs, especially other females (potential breeding competition). A normal heat lasts about three weeks, during which the bitch has a bloody discharge. As she approaches the fertile part of the cycle, usually about days 12 to 16, she exudes more pheromones, which are the chemicals that attract and stimulate breeding behavior in males. She will want to advertise her availability far and wide, and hence will urinate often, and sometimes in places she would normally avoid (such as the livingroom). She will be very distracted, interested only in breeding, and her aggressiveness to other bitches will escalate. After passing her fertile period, she will also be aggressive to males. Once her heat cycle has passed, her behavior will settle down to normal, unless she has difficulty during the false pregnancy period.

Bitches do not go through a "menopause" or cessation of estrus cycles. They will continue to go into estrus even as geriatric animals, although the timing may change. Litters produced by geriatric bitches show reduced litter size (fewer pups), increased pup mortality, and increased probability of needing a caesarian delivery.

Physical Problems In The Intact Bitch

Cystic ovaries - - Intact bitches occasionally develop cysts on the ovaries which produced excess amounts of estrogen, which lead to excessive symptoms of false pregnancy, incl8uding aggression towards any "threat" to her "puppies". This condition can cause a discharge which is attractive to the male, even though the bitch has no associated desire for sexual behavior. She is likely to become aggressive to any male attempting to breed her. The usual treatment for this condition is spaying.

Pyometra (uterine infection) - - Uterine infections in intact bitches are fairly common, especially following birth of a litter, or after being in heat. Whenever the cervix is open, as it must be for delivery of pups and for discharge of estrus secretions and to allow sperm access to ova in the uterine horns, the bitch is at risk for infectious agents to move into the uterus. The uterine lining is an excellent medium for the growth of pathogenic bacteria, and any such bacteria that gain entrance into the uterus can cause serious problems. If the cervix is still open when the infection takes hold, a smelly discharge is produced, and it is fairly obvious that she has an infection. However, if the cervix closes (its normal condition during periods of anestrus. - between heat cycles) after the pathogen has entered the uterus but before the discharge is produced, the bitch will have a "closed cervix pyometra", the discharge will be contained in the uterus, producing swelling of the abdomen, and the toxins given off by the bacteria will be absorbed into the bloodstream, producing a systemic infection. By the time his condition gives external symptoms, it is often life-threatening, and an emergency spay is necessary.

Mastitis (breast infection) - - Mammary glands often become infected as a consequence of uterine infection, or because of lesions caused by nursing pups after their "milk" teeth begin to erupt (these teeth are very sharp!). Common infectious agents are streptococcus and staphylococcus bacteria. Abscesses are often present in the mammary gland tissue. Pups who nurse on an infected breast can become infected as well. Treatment but lancing the abscesses, antibiotics will usually heal the mastitis. In severe or chronic cases, spaying is necessary. If the infected breast becomes gangrenous, pups who are still nursing will have to be taken off the bitch and hand fed.

Mammary cancer - - As with human females, mammary cancer in the bitch is sensitive to the amount of estrogen exposure. Research in dogs has produced the following statistics: the bitch who remains intact for her entire life has a 50% probability of developing mammary cancer; the bitch spayed before her first estrus cycle has about a 5% probability. A bitch spayed later in her life has a probability between 5% and 50% with the probability increasing with every subsequent estrus cycle.

Life After Spaying

Its very easy to tell what a bitch's temperament will be like after she is spayed - - it will be just the same as it is when she is in between estrus cycles, but without the complicating issues of behavior specific to false pregnancies. The spayed bitch tends to be less aggressive to other dogs of both sexes. The female physical characteristics (more feminine head, less neck and should development) are not dependant on estrogen level and will be the same in the bitch spayed young as in the intact bitch.There is one minor problem that the spayed bitch may have - - due to the lack of cyclical estrogen an occasional bitch will have a problem with dribbling of urine, cause by loss of muscle tone in the bladder wall and the urinary sphincter. This usually shows up in the older animals, but rarely it can manifest in a younger one. The solution is usually simple - - small doses of synthetic estrogen over a period of time will reverse the problem. If sphincter inadequacy is still present, another medication, phenylpropanolamine, will often restore sphincter tone sufficiently to stop dribbling.

The great benefits to the bitch of being spayed are: not having to go through emotional and physical stress of being in heat 2 or 3 times a year; nearly removing the risk of mammary cancer; removing the risk of uterine infections; and, for the dog with a job (hunting, service, obedience showing, search and rescue, police, herding, etc.) being able to perform the job year-ro8und, not just the few weeks when in between heat cycles.

One Last Word

Removing the stress of breeding behavior and the results does not take away from your dog's enjoyment of life. Sexual behavior in dogs is entirely chemically motivated. If the chemical stimulation is not there, the desire is not there. The dogs don't miss it! {Dogs don't have sexual hang-ups - - only people do.} Think about how you will respond if your intact male gets out, and comes back home with his ear ripped off and his throat torn open. Remember the risk to your bitch's life whenever you think she "ought to have a chance to experience motherhood." Remember who will have to feed and clean those puppies if she can't. Think about how much money, time, and effort you will spend raising those pups properly, and then not finding really good homes for them. Or finding out the pups have genetic problems and you can't place them at all. If you think your children need to see "the miracle of life" by watching the pups be born, think of how they will feel if the mother dog dies in the process, or if the pups are born dead. Maybe a good video tape would be a better educations experience for your kids.

Be a responsible dog owner - - be good to your best friends - - alter your pet!

If you have further questions about5 this, please fee free to consult with your vet, your obedience instructor, or call me, Jean Petersen, at (651) 452-4209.