Spay and Neuter FAQ's - By Jan Morgan
My vet tells me that neutering my male dog will keep him from getting cancer.
Is that true?
While it has been shown in some studies that neutering male dogs eliminates:
~ the small risk (probably <1%) of dying from testicular cancer
~ reduces the risk of non-cancerous prostate disorders
~ reduces the risk of perianal fistulas
~ may possibly reduce the risk of diabetes (data inconclusive)
Studies have also shown that neutering male dogs:
~ particularly if done before maturity, increases the risk of
osteosarcoma (bone cancer) by a factor of 3.8; this is a
common cancer in medium/large and larger breeds with
a poor prognosis.
~ increases the risk of cardiac hemangiosarcoma by a factor
of 1.6; this is a common cancer and major cause of death in
some breeds.
~ triples the risk of hypothyroidism
~ increases the risk of geriatric cognitive impairment
~ triples the risk of obesity, a common health problem in dogs
with it the many associated health problems associated with
obesity.
~ quadruples the otherwise small risk (<0.6%) of prostate cancer
~ doubles the otherwise small risk (<1%) of urinary tract cancers
~ increases the risk of orthopedic disorders
~ increases the risk of adverse reactions to vaccinations
My vet tells me that if I spay my female dog, I will reduce the risk of mammary tumors and pyometra. Is that true?
In order to answer this question, one must first understand a little about canine physiology. Pyometra is an infection that occurs in the uterus. The vet is right if you remove the uterus, which is the accepted method of spay, then it stands to reason your dog will never get pyometra. Additionally, if you remove the cervix and ovaries then there will be no hormone producing enzymes to begin the cycle of mammary tumors.
Keep in mind that pyometra kills about 1% of intact female dogs, and that number decreases by a minimum of one half in Naturally Reared (NR) dogs (probably more). If you are committed to NR, then you have already reduced the already low chance of your dog (male or female) from getting and succumbing to cancer of any kind.
Spaying female dogs:
~ if done before 2.5 years of age, reduces the risk of mammary
tumors.
~ nearly eliminates the risk of pyometra, which otherwise would
affect about 23% of intact female dogs; pyometra only kills
about 1% of intact female dogs.
~ reduces the risk of perianal fistulas
~ removes the very small risk (0.5%) from uterine, cervical, and
ovarian tumors
However, spaying female dogs:
~ if done before maturity, increases the risk of osteosarcoma by
a factor of 3.1; this is a common cancer in larger breeds with a
poor prognosis.
~ increases the risk of splenic hemangiosarcoma by a factor of
2.2 and cardiac hemangiosarcoma by a factor of >5; this is a
common cancer and major cause of death in some breeds.
~ triples the risk of hypothyroidism
~ increases the risk of obesity by a factor of 1.6-2, a common
health problem in dogs with many associated health problems
~ causes urinary "spay incontinence" in 4-20% of female dogs
~ increases the risk of persistent or recurring urinary tract
infections by a factor of 3-4
~ increases the risk of recessed vulva, vaginal dermatitis, and
vaginitis, especially for female dogs spayed before puberty
~ doubles the small risk (<1%) of urinary tract tumors
~ increases the risk of orthopedic disorders
~ increases the risk of adverse reactions to vaccinations
My vet tells me that neutering my male dog will keep him from marking. Is that true?
Most people who own dogs will tell you that neutered and intact dogs both mark. They are dogs, and dogs like many mammals mark their territories. It is a natural, normal part of the species. Studies have show that males neutered before the age of 6 months mark continually throughout their lives.
Most vets will tell you that early neutering and spaying is perfectly
safe and a good thing. When pressed they will tell you that this
practice "can" or "may" result in obesity, urinary incontinence,
stunted growth, behavioral abnormalities and other such problems.
However, they will be quick to point out that there is little evidence
to support the increased risk. This is simply not true. Recent studies
support the fact that early S/N is detrimental (see excerpt from
AVMA study below).
What about population Control? I’m not going to breed,
shouldn’t I spay or neuter my pet?
Americans are essentially lazy (present company excluded) and want the easy way out with animals, all the while touting pet population control. Most never take into consideration what they are doing to their animals. Estrogens and Testosterone are known to play a role in every aspect of growth, development AND adult maintenance. Ask any woman going through menopause, just how important the presence of "naturally" produced estrogen is! We must not delude ourselves into thinking it is any different in other animals? It cannot be - it is nature. Responsible pet ownership includes keeping tabs on your intact dogs. Many people keep intact animals and never have a problem. Locked gates, separation of males and females during estrus (twice a year) and a bit of patience is all that is needed to successfully keep your animal healthy and whole.
My vet tells me that spaying and neutering is safe and will not harm my dog. Is the procedure safe and are there any long term side effects?
As an osteologist and an animal lover, I have seen the effects of
early S/N on animals - dogs in particular, and many of the problems
we see in our dogs can be directly related to early sterilization,
particularly issues directly related to bone and joint development.
Pre-pubertal sterilization significantly delays epiphyseal (growth
plate) closure, due to lack of gonadal steroids. The numbers speak for themselves. In a study done by Salmeri KR, Bloomberg MS, Scrugs SL, Shille VS: Gonadectomy in immature dogs: effects on skeletal, physical, and behavioral development. J Am Vet Med Assoc 198:1193, 1991, it was shown that epiphyseal closure occurred at 60 weeks of age in puppies spayed/neutered at 7 weeks, 55 weeks of age in puppies spayed/neutered at 7 months and 42 weeks in puppies not spayed/neutered at all. This is significant due to the fact that epiphyseal closure affects bone and joint growth and gait. In other words, we could avoid a lot of joint issues like hip displasia, luxating patellae and other abnormalities if we didn't rush out and spay young puppies. The age of closure is significantly different in all three groups! The result in unsprayed/unneutered dogs is a longer period of growth. What this boils down to is longer and stronger long bones which will support the increased size of dogs in adulthood; therefore, fewer joint and bone issues.
I have also seen the result of early spaying and neutering in the
teeth of these animals. Naturally reared, raw fed, unaltered dogs
have healthier teeth and jaws, fewer dental problems and denser,
more powerful teeth. I realize to you and I, as Natural Rearers,
this all makes perfect sense and is very logical. If hormones are
responsible for growth and development then it is obvious that the
longer an animal is allowed to grow and develop naturally, the
healthier that animal will be. But the medical world will argue to
the death, preserving their added income.
Note: 75% of a veterinary clinic’s income comes from Vaccinations,
Spay/Neuter, and the sale of so-called high quality and prescription
pet foods. So, it is in their best interests, financially, to push for early
spay and neuter.
There are many other negatives to early sterilization: sexual
infantilism, with poorly developed reproductive tracts, poor play
behavior and general activity levels. We all know that in the wild,
play behavior is necessary for position within the pack. Early
sterilization can circumvent this natural progression. Many of the
risks are associated with any early age surgery. Anesthetic problems occur because younger animals have greater oxygen consumption than adults and therefore there is a greater risk of hypothermia during aesthesia due to their small size. Intubation due to the smaller size and less rigid structure of the animal's tracheal cartilage is also a concern. And of course, the medication itself can be very dangerous to puppies and kittens, as well as adult animals. In Brachycephalic (snub-nosed) dogs the dangers of anesthetic increase 10 fold. Add to this the new “antibiotic whether they need it or not” mentality and you have a chemical overload in addition to major surgery.
I hate that there are not more studies being done on this topic, but we must remember that most studies done at medical facilities and universities in this country are funded by pharmaceutical, pet food and medical companies and are therefore, biased by default. However, a most telling study was recently done, which confirms what Natural Rearers have known all along. In a study appearing in the Journal of American Veterinary Medical Association, the long-term risks and benefits of early age gonadectomy in dogs was done to compare with traditional age gonadectomy. 1,842 dogs underwent gonadectomy and were adopted from an animal shelter before 1 year of age; follow-up was available for as long as 11 years after surgery. Adopters completed a questionnaire about their dogs' behavior and medical history. When possible, the dogs' veterinary records were reviewed. Associations between the occurrence of 56 medical and behavioral conditions and dogs' age at gonadectomy were evaluated.
The results among female dogs included increased rate of cystitis and decreasing age at gonadectomy was associated with increased rate of urinary incontinence. Among male and female dogs with early-age gonadectomy included hip dysplasia, noise phobias, and increased sexual behaviors(JAVMA, 2004, Vol. 224, No. 3*).
Natural rearing comes under fire every day,
because if it were to take off these industries would lose a lot of
profit, and that is ultimately what it is all about. British vets and
veterinarians in other country's vehemently oppose the "US stance" on early sterilization, and really don't put much stock in American
"studies" that show no adverse effects of early N/S. They know how
these studies are funded.
*Journal of the American Veterinary Medical Association
February 1, 2004, Vol. 224, No. 3, Pages 380-387
doi: 10.2460/javma.2004.224.380
Long-term risks and benefits of early-age gonadectomy in dogs
C. Victor Spain, DVM, PhDJanet M. Scarlett, DVM, PhDKatherine A. Houpt, VMD, PhD, DACVB
Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. (Spain, Scarlett); Present address: Philadelphia Department of Public Health, Division of Disease Control, 500 S Broad St, Philadelphia, PA 19146. (Spain); Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. (Houpt)
I have included the following article for additional information:
EARLY SPAYING AND NEUTERING, AND THE
DANGERS THAT CAN BE INVOLVED
(written by Pam Davol, a noted research scientist and a genetic expert)
Owners who are considering neutering need to take all factors into consideration, not simply the benefits of neutering when making a decision as to when to neuter.
If one looks close enough, one will find that neutering is one of those topics in veterinary medicine that is extremely biased: that is, most often one will find more emphasis placed on the pros of neutering with more often than not, very little or no discussion of the cons. Veterinarians, and responsible breeders as well, face a true dilemma when discussing neutering. The overpopulation crisis presents a very real concern with regard to the necessity of ownership responsibility. Prepubertal/early neutering or required neutering provides a means for vets/breeders to enforce owner responsibility by ensuring surgical sterilization of dogs not destined to be used in breeding programs. Again, this enforced neutering is typically presented along with a preamble of all the benefits that go along with neutering. However, I believe that breeders, if not veterinarians, need to begin questioning the ethics of this approach to prompt or require owners to neuter; especially in light of the facts that early neutering may not be as benign a process to the health of a dog as one would believe.
Yes, neutering prior to the beginning of estrus does reduce risk for mammary cancer in females, but it also significantly increases risk for urinary incontinence in bitches which predisposes these bitches to diethylstilbestrol (DES) dependency (Stocklin-Gautschi et al., J. Reprod. Fertile. Suppl. 57:233-6, 2001 and many other references)--in some instances, DES is not effective at controlling incontinence and will force some owners to elect euthanasia. Though with lesser risk compared to females, early neutering also increases risk of urethral sphincter incontinence in males (A. Aaron et al., Vet Rec. 139:542-6, 1996.)
With regard to cancer, spayed females have a 4 times greater risk for developing cardiac hemangiosarcomas (vascular tumors) compared to intact females (neutered males also show a significant increase in risk for these tumors compared to intact males) (Ware and Hysper, J. Vet. Intern. Med. 13:95-103, 1999.). Additionally, both neutered males and females have a 2-fold greater risk for developing bone tumors (osteosarcoma) compared to intact males and females (Ru et al., Vet J. 156:31-9, 1998.).
Some evidence suggests that early neutering may also predispose to endocrine disorders later in life (Panciera DL. J. Am. Vet. Med. Assoc., 204:761-7 1994.). Furthermore, there is also an indication that early neutering (because absence of sex hormones delays maturation of osteoclasts and thus results in delayed closing of the growth plates in the long-bones) may predispose to increased risk for various orthopedic disorders (such as cruciate ligament disease as I had mentioned in a previous post). Also, some evidence suggests that there is a correlation between increased time for growth plate closure and incidence of HD in Labs (Todhunter et al. J. Am. Vet Assoc., 1997).
If one conducted a research of the literature on the detrimental effects on physiological development associated with sex hormone deficiencies during adolescent development in any other species other than the dog and cat, one will find a wealth of literature stressing the importance of sex hormones for sound physiological, endocrine and metabolic development. Additionally, if one examines the scientific research that reports the benefits of early neutering in absence of any side-effects in dogs, one will discover that the methodology of these studies are designed in very specific ways to assure that outcome in neutering is presented in a favorable light (this does not mean that the data is biased, this simply means that the comparisons made do not provide for adequate interpretation of long-term effects of neutering).
In light of this, though it is understandable for vets/breeders to urge dog owners to neuter their pets early with regard to the greater good (i.e. reducing risk of accidental breeding), the physiological soundness of the individual dog should take precedence over any other issues. As such, it is my opinion, based upon the literature that I have reviewed that to reduce risks to physiological soundness, etc, that I am of the personal opinion that dogs should be a minimum of 1 year of age before neutering.
"And in Addition"
To Neuter or not to Neuter...
There are a number of studies that suggest that those of us with canine athletes should be carefully considering our current recommendations to spay or neuter all dogs at 6 months of age or earlier. A study by Salmeri et al in 1991 (Salmeri et al JAVMA 1991;198:1193-1203) found that bitches spayed at 7 weeks were significantly taller than those spayed at 7 months, and that those spayed at at 7 months had significantly delayed closure of the growth plates than those not spayed (or presumably spayed after the growth plates had closed). The sex hormones close the growth plates, so the bones of dogs or bitches neutered or spayed before puberty continue to grow. This growth frequently results in a dog that does not have the same body proportions as he/she was genetically meant to. For example, if the femur is normal length at 8 months when a dog gets spayed or neutered, but the tibia, which normally stops growing at 12 to 14 months of age continues to grow, then an abnormal angle may develop at the stifle. In addition, with the extra growth, the lower leg below the stifle becomes heavier (because it is longer), causing increased stresses on the cranial cruciate ligament. This is confirmed by a recent study showing that spayed and neutered dogs have a higher incidence of CCL rupture (Slauterbeck JR, Pankratz K, Xu KT, Bozeman SC, Hardy DM. Canine ovariohysterectomy and orchiectomy increases the prevalence of ACL injury. Clin Orthop Relat Res. 2004 Dec;(429):301-5).
In addition, a study in 2004 in JAVMA (Spain et al. JAVMA 2004;224:380-387) showed that dogs spayed or neutered before 5 1/2 months had a significantly higher incidence of hip dysplasia than dogs spayed or neutered after 5 1/2 months of age. If I were a breeder, I would be very concerned about this, because it would mean that I might be making incorrect breeding decisions if I were considering the hip status of pups I sold that were spayed or neutered early. Interestingly, this same author also identified an increased incidence of sexual behaviors in males and females that were neutered early.
A number of studies, including the one by Spain referenced above, have shown that there is an increase in the incidence of female urinary incontinence in dogs spayed early. This problem is an inconvenience, and not usually life-threatening, but nonetheless one that requires the dog to be medicated for life.
Yes, there is the concern that there is an increased risk of mammary cancer if a dog has a heat cycle. But it is my observation that fewer canine athletes develop mammary cancer as compared to the number that damage their cranial cruciate ligaments. In addition, only about 50 % of mammary cancers are malignant, and those that are malignant don't metastasize very often, particularly in these days when there is early identification and removal of lumps found on our dogs.
In addition, when considering cancer, there is another study of 3218 dogs that showed that dogs that were neutered before a year of age had a significantly increased chance of developing bone cancer (Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters D, Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1434-40), a cancer that is much more life-threatening than mammary cancer, and which affects both genders.
Finally, in another study, unneutered males were significantly less likely than neutered males to suffer cognitive impairment when they were older (Hart BL. J Am Vet Med Assoc. 2001 Jul 1;219(1):51-6). Females were not evaluated in that study.
For these reasons, I have significant concerns with spaying or neutering dogs before puberty, particularly for the canine athlete. And frankly, if something is more healthy for the canine athlete, would we not also want that for pet dogs as well? I think it is important, therefore, that we assess each situation individually. If a pet dog is going to live with an intelligent, well-informed family that understands the problem of pet overpopulation and can be trusted to keep their dogs under their control at all times and to not breed them, I do not recommend spaying or neutering.
Spay and Neuter Frequently
Asked Questions
