Article © 2002 Darlene Arden. First published in DOG world, March 2002.

Early Spay / Neuter
How young is too young?

Jack's vet refused to neuter him before he was six months old, despite his having been ready at three months. Jack no longer goes to that vet. Photo by Rebecca Brynteson Conner.

Just about every breeder has sold a puppy on a spay/neuter contract, only to find out later that the contract hasn't been honored. Meanwhile, although animal shelters across America extract promises from puppy and kitten adopters that they will bring the pet back to be neutered, in some states fewer than half of those promises are ever kept. What can be done? Increasingly, the answer is early spay/neuter. The technique has been around for a couple of decades, and recent research has shown it to be a really good choice.

Referred to as pediatric, juvenile or prepubertal neutering (to avoid the implication that "early" means it is being done too soon), the procedure is performed on animals as young as six to eight weeks old, and up to six months. (Many veterinarians use two pounds as the lower limit, rather than any specific age.)

Generally, five to six months has been the conventional age for neutering, but it was arrived at using purely anecdotal information. "A search of the veterinary literature failed to turn up any studies or research to determine the best age to neuter dogs and cats," says Lila Miller, DVM, the ASPCA's senior director of animal sciences and veterinary advisor. "In addition, although many veterinarians express reluctance to perform pediatric neutering because of the lack of formal studies about the long-term effects, no studies have been performed to determine the long-term safety of performing the surgery at six to seven months of age, either.

Aztec the Occicat photo Shara Rendell-Smock

"What is not commonly known is that in the 1900s it was recommended to neuter animals before puberty, and in some cases, soon after weaning," Miller continues. "Texts from the 1950s also recommended doing it at five months of age or before puberty, using Nembutal or ether anesthesia. Pediatric neutering is not a new concept!"

Making Sure It's Done
Veterinarians have been performing pediatric spay/neuters for animal shelters since the 1980s. The practice can help reduce the number of unwanted animals who are euthanized every year. Also, the shelter doesn't have to attempt to track down every adopter to ensure compliance with spay/neuter agreements, and the owner saves a trip to the veterinarian to have the procedure done.

The Homeless Pet Placement League in Houston, Texas, began doing pediatric spay/neuter in the fall of 1991. An innovative policy at the time, the shelter is satisfied with the results, "We're not seeing any long-term problems that we know of," says Debby Ryan, member of the Board of Directors and past president. "My organization has a contract with the low-cost clinic in town, SNAP [Spay/Neuter Assistance Program]." SNAP also takes a huge trailer, outfitted as a mobile surgery clinic, into low-income neighborhoods four days a week to for free spay/neuter operations. The clinic's minimum is three months old or three pounds.

Breeders are experiencing similar compliance problems with spay/neuter agreements--and, increasingly, are turning to the same solution. Responsible breeders don't want dogs bred if they have hereditary conformational defects and genetic medical conditions, and pediatric spay/neuter can guarantee that.

Betty Jane Reece-Weaver of Mountain Home, Idaho, breeds German Shorthaired Pointers. Her serious involvement with dogs began in her native Canada. She decided to try early spay/neuter after an unfortunate experience. "Even though I tried really hard to place the pups from the first litter in great homes, sadly, a couple of puppies ended up with people who had sat in my kitchen and lied to me," Reece-Weaver recalls. "One was to have been shown and then perhaps bred if all clearances were obtained. The owners never showed the dog--heck, they never even kept its vaccinations up to date--and then contacted me to lift the Non-Breeding Agreement [the Canadian Kennel Club's equivalent of a Limited Registration, except you can enter shows under such an agreement]. This dog was likely bred, although I never lifted the agreement.

"Another was a Group First winner and was co-owned with someone in another breed," Reece-Weaver continues. "She came back for boarding in hideous condition, and they didn't seem to care. She's now fat and happy, living the life of leisure on a farm with a wonderful, loving family. Luckily, I moved and found a vet who also bred dogs and was doing the early neutering. After much thought I decided I would rather have any pup bred safe from any 'accidents,' if it was going to be a champion only. And I am much more difficult to get a dog from, intact or otherwise."

Ethel, a shelter rescue, is the proud owner of Robin and Steve Dale.

Papillon breeder and AKC judge Arlene Czech has been spaying and neutering her pet-quality puppies for several years. "After the Papillon won Westminster [in 1999], we breeders were deluged with requests for 'breeding' stock," says Czech. "There was no concern on their part about the quality of the dog. I even had requests for a breeding pair!" Some breeders will hold back papers until there is a note from the veterinarian stating that the puppy has been spayed or neutered, but sometimes puppy buyers care more about breeding the dog than they do about having official AKC registration papers.

"This isn't for everyone, and even I am still researching the effects of it, but if you have spent any time walking through the local shelter or reading the classified ads, you have to realize that something needs to be done to stop irresponsible breeding," says Reece-Weaver. "People will buy a dog and a bitch, then start having litter after litter, placing them with no screening of the buyers other than whether the check will clear. Some just don't know about health testing, screening buyers, taking pups back if they can't be kept any longer by their families--sadly, some just see the dollar signs."

Zak takes a moment to pause.
Photo by Stuart Band

Czech also had no problems spaying her pups at five months of age. "My vet will do it if the puppy is in good health," she says. Reece-Weaver started out with a veterinarian who would spay/neuter pups at eight weeks of age, but her current vet likes to wait just a few weeks more. "The ones I've had done have been around 10 to 12 weeks, and I like that age," says Reece-Weaver.

"Strangely, more people are concerned about having to wait to get the pup than about the alteration," she continues. "Many have heard the pup must go to his new home no later than eight weeks or he won't bond with them. This is simply not true, and research is showing that another couple of weeks is beneficial to the pup's development. The simple fact is, I don't rush my pups out the door--yes, it's more work for me, but I get a chance to start them on training (crating, obedience, housebreaking, walking on a leash, and bird work). I also get a better feel for the temperament and can better fit the individual into their new family's lifestyle."

"I am strongly in favor of breeders who want to walk the talk," says veterinarian Toodie Connor, a noted Tibetan Terrier breeder and owner of Animal Care Center just outside of Seattle, Washington. Connor believes early spay/neuter is the only way to ensure dogs won't be bred; papers, such as contracts or Limited Registration forms, simply aren't enough. "I believe that responsible breeders keep their puppies until they are twelve weeks old, and they can be spayed or neutered at that age," says Connor.

As a veterinarian, Connor has spayed hamsters, so she has no qualms about spaying or neutering young puppies, "They heal faster; they act as if they've never had anything done to them."

Seals of Approval
Pediatric spay/neuter has been endorsed by the American Veterinarian Medical Association, the American Animal Hospital Association, the American Kennel Club, the Cat Fanciers' Association, many state veterinary medical associations, and a host of other associations. The Association of Veterinarians for Animal Rights and the University of California at Davis School of Veterinary Medicine have co-produced a video, Early-Age Spay/Neuter, A Practical Guide for Veterinarians, demonstrating the procedure on both kittens and puppies, and reassuring veterinarians of its safety.

Red and Blue, photo Julie Clint

"In our third-year surgery lectures, I discuss the advantages and safety of early spay/neuter," says Clare R. Gregory, DVM, DACVS, a professor in the Department of Surgical and Radiological Sciences at UC-Davis. "In our experience at UC-Davis, the procedure is as safe as the procedures in older animals."

"Pediatric spay/neuter is safe and is less stressful on the patient than waiting until the animal is older, [when he or she also] loses the benefits of avoiding accidental pregnancy or mammary gland cancer, pyometras, false pregnancies, prostate disease and behavioral problems," says Miller.

What About the Risks?
"The major concern is the perioperative management of the pups and kittens," says Gregory. "Body temperatures and blood glucose levels have to be kept at adequate levels. Logistically, the young animals require more attention in the hospital than older animals. Overall, however, we have found that these procedures can be performed safely and successfully."

If Connor has any reservations at all about the procedure, it's the use of anesthesia in these youngsters. "Because they're so small, you don't have any margin for error," she explains.

"Leading anesthesiologists and veterinarians familiar with the procedures have advocated using whatever anesthetic protocols practitioners are familiar with and simply reducing the dosage for the weight of the patient," says Miller. "No special drugs or protocols must be used. Careful attention to dosing and monitoring is the key to safe anesthesia, as in any other surgical procedure. Younger patients recover from the anesthesia much faster than older animals. Pediatric patients will be up and eating within 20 minutes after the completion of surgery, as opposed to several hours for conventional age patients. They also recover from the surgery and resume normal activities much faster."

"The main risks are from hypothermia and hypoglycemia. These risks are easily minimized, Miller continues. "Patients should be fed a small meal in the morning before surgery and fasted only a couple of hours to prevent hypoglycemia. Minimal shaving of hair, avoiding the use of alcohol during surgery prep, using heating pads during surgery and providing warmth during recovery eliminates the risk of hypothermia."

"Studies have been conducted and published that indicate the procedure is safe, and there is no increase in complications short-term from the actual anesthesia or surgery," says Miller. In the long term, there is, so far, no evidence of any adverse physical side effects associated with pediatric surgery. "The growth plates close later, resulting in bones that are a little longer, rather than stunted growth--which is the common misconception," says Miller. "There is no known significance to this increase in bone length. Other concerns about obesity, perivulvular dermatitis and urinary incontinence have been found to be groundless. They may be found in animals regardless of the age at neutering or their sexual status," she adds.

Lewis, the Shih Tzu, is appropriately attired for
a Winter walk.  Photo by Ronni Warren Ashcroft. 

"Most veterinarians who perform pediatric neutering admit that they prefer it to conventional age neutering, once they become comfortable performing it," Miller continues. "It is not microsurgery, and requires no special skills or equipment beyond good surgical technique and anesthesia. The patients are handled more easily, bleeding and fat are minimal, and the patients can go home the same day. It merely requires an open mind and a willingness to change and try something new. Many veterinarians say they do not perform the procedures because it is not necessary, or their clients are not asking for it, but that denies the responsibility of the veterinarian to participate in solving the pet overpopulation problem. It is a social problem, not a shelter one."

"I would tell people that if their private veterinarian is not willing to do it, they need to find someone else who is," says Ryan. Most shelters and humane organizations can help you find a local veterinarian who performs pediatric spays and neuters. Your local humane society is the first place to call.

Terzo Celebrates Valentine's Day.
Photo: Bobbi Florio Graham

Are There Behavior Problems?
There have been some interesting theories put forth about behavioral consequences of pediatric spay/neuter. One is that females who were in utero between two males have more testosterone at birth and are more likely to become aggressive toward their owners after pediatric spaying. But according to Karen Overall, VMD, DACVB, who is head of the Behavior Clinic at the University of Pennsylvania School of Veterinary Medicine, there's really no support for that hypothesis. While there is some evidence that it's true for rats, the theory just doesn't hold up when applied to dogs.


There has also been some concern that there were early signs of aggression in female dogs who were already overly assertive before they were spayed. In a study done in 1990 at the Veterinary College of Edinburgh University, researchers Valery O'Farrell and Erica Peachey hypothesized that pediatric spaying would increase the likelihood of expressing undesirable androgynous traits, since removing the ovaries would leave comparatively more testosterone in the body--thus creating conditions the opposite of those that arise when males are neutered. They compared the behavior of 150 spayed females with a control group (matched by breed and age) of 150 unspayed females. In their study, spayed females showed a significant increase in dominance-related aggression following surgery, especially if they were under one year of age and had exhibited aggressive behavior prior to spaying.

However, other studies have found no difference in behavior between groups of spayed and unspayed females. Anecdotally, breeders who use the procedure are finding no problems. Reece-Weaver, for example, has had no aggression problems with bitches who were spayed early. "I've not heard of any problems that were being associated with the early alteration or any concerns with temperament at all," she says.

John Wright, PhD, a certified applied animal behaviorist and psychology professor at Mercer University in Macon, Georgia, believes there is "a lack of well-controlled, clear research addressing the greater pieces of the puzzle." Wright is in the third and final year of a three-year study funded by The Pet Care Trust and Mercer University to look at how puppies behave in the first three years following adoption and to try to discover whether pediatric neutering (six to 13 weeks) has a different outcome in terms of behavior and health, compared to traditional age (six months) neutering.

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Together with co-investigators from the MSPCA (Massachusetts Society for the Prevention of Cruelty to Animals), Wright is looking at differences in elimination, feeding, separation-related behaviors, veterinary medical issues and aggression. The study uses a split-litter design: Half the puppies from each litter studied were spayed or neutered early, before placement, and half were neutered at the traditional time. The adopters agreed to participate in a study about what puppies do in their first few years of life, but were unaware of the pediatric neutering aspect of the study.

The adopters were interviewed one month after adoption, and again six months after adoption. After the second interview, the adopters with puppies who hadn't yet been neutered were called and a free spay/neuter was scheduled. There was another assessment one year after adoption, then again at two years and at three years. Wright and his colleagues are now putting together the sdata and studying it.

So far they have found that behavior problems can come up at different times and in different frequencies, but overall, there were fewer behavior problems in both groups than had been expected. "Conventional wisdom" holds that up to 33 percent of shelter-adopted puppies are going to have behavior problems, but the statistics simply haven't borne that out. In the first month following adoption, behavior problems (mostly involving biting and elimination) have shown up, but many were specific to puppyhood and were resolved by the time the puppy was six months of age. And what about the pediatric spay/neuter group? "The insult of the surgery seemed to be influencing behaviors in only a few cases," says Wright.

He is quick to point out that these are preliminary results in his own study, and that he and his colleagues continue to study the research findings. However, the preliminary news is good. In fact, all things considered, the good news about pediatric spay/neuter is that it's all good news.

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