What is the name of the spay/neuter study?

Question

My vet and the people at the local pound are always saying that there are severall health benifits of spaying/neutering according to "studies" and yet whenever i ask where i can find a copy of this study they all can't tell me.

i had looked on the net off and on for the last couple years and there was a couple sites that said that there was also negative side effects as well but once again no specific studies.

please no spca crusaders posting their "facts" i would actually like to see this study itself if it actually truly does exist.

Answer 1

http://www.mmilani.com/commentary-200511.html

http://www.mmilani.com/commentary-200509.html

http://www.littleriverlabs.com/neuter.htm

http://www.showdogsupersite.com/kenlclub/breedvet/castrationindogs.html


Good for you for thinking for yourself instead of blindly following the brainwashed masses!


The OFA has done a study on effects of young S/N on a dogs structure. You may find the article on their website.

This is not to say there are not benefits to S/N, but you have to weigh the positive against the negative.

Answer 2

WHAT YOU SHOULD KNOW ABOUT SEXUAL HORMONES PHYSIOLOGICAL ROLES

Precision: in the following text, sterilisation in female refers to ovariectomy (ovaries ablation), and sterilisation in males refers to castration (testicules ablation).

SEXUAL HORMONES PHYSIOLOGICAL ROLES IN MAMMALS

Sexual hormones are anabolic steroids. They play a role in the growth of many organs. They enhance the synthesis of proteins in muscles. They play an important role in the growth of long bones (legs...), and later, they inhibit further linear growth of the bones (1). That means that depending on the age at which the dog is sterilized, he will be either shorter or bigger (which doesn't mean that there will necessarily be a big difference).

Red blood cells in mature mammals dont have a nucleus. Therefore, they cannot divide. Furthermore, having a limited lifespan, they have to be constantly nenewed (2). Sexual hormones play a role in that renewal, by acting directly on the stem cells, and by stimulating erythropoietin production (which also stimulates the stem cells) (1,3).







CONSEQUENCES OF STERILIZATION

Sterilization eliminates some kind of health problems related with the reproductory system. In males, it eliminates the risks of testicular cancer. In females, it eliminates the risks of pyomtra (a condition of hormonal imbalance that causes an infection of the uterus that needs to be treated extremely rapidly), and reduces the risks of mammary cancer if the ***** is sterilized before her first heat (the ovariectomy done before the first heat reduces the risk of mammary cancer to 0.5% of the risk in intact bitches, and the ovariectomy done after one heat period reduces the risk to 8% of that in intact bitches. The bitches sterilized after they have reached maturity have the same risk as intact bitches (3)). But in the case of an immature *****, she's not mature physically and emotionally.

Puppies go trough different stages while they mature, and that's because of hormonal changes. Many dog psychologists think that a dog who is deprived from his sexual hormones before he/she reaches maturity is more inclined to get behavioral problems. We think that he/she will need more stability and will need to know exactly where he/she stands in his human family. Owners who chose sterilization should know about that in order to prevent problems to happen.

Testosterone and oestrogen deficiencies can induce urinary incontinence (3,4,5,14,15). It occurs in 20% of spayed dogs (6) . This effect is not well understood but sexual hormones probably have effects on the urethral sphincter (14,15). And this problem is more frequent on females then males (3). But it can happen in males also (7). It appears that larger breeds are at greater risk (5,7). Some breeds are known to have a predisposition to urinary incontinence related to spaying: 65% of Boxers are affected, and Dobermans and Giant Schnauzers have a more then average disposition to this condition (5,6).

A study showed that spayed bitches have a higher risk of developping urinary tract infections, the sexual hormone deprivation having an effect on the bladder defense system (13).

A study shows that over 80% of intact dogs over 5 years old developp benign prostatic hypertrophy. But neutered dogs would have a higher risk of developping prostatic cancer (adenocarcinoma) (16). Another study shows that castrated dogs have an increased prevalence of pulmonary metastasis then intact dogs (17).

Another study showed that the more frequent canine prostatic diseases are: bacterial prostatitis, prostatic cyst, prostatic adenocarcinoma and benign hyperplasia (18). This study also showed that the more frequent prostatic disease in castrated dogs is the prostatic adenocarcinome (cancer) (18). In that study, the most common breed with prostatic diseases was the Doberman Pinscher (18).

It seems that there are more spayed bitches than intact ones that are affected by hypothyroidism (3). A study demonstrated that sterilized dogs (males and females) have a higher risk of developing hypothyroidism than intact females (8).

Neutering can cause dermatosis including mild alopecia in dogs an cats, but this condition is not common (3). It can also cause feline endocrine alopecia, mainly in neutered male cats (3).

One of the potential negative effects of sterilization of bitches is that dominant bitches might become more dominant and develop aggressivity (9).

It's also interesting to know that sterilization lowers the metabolism. This is the reason why sterilized animals have a tendancy to obesity (3).

The hypothetical cause of the hyperadrenocorticism in ferrets, health problem that occurs in a very high percentage of ferrets, mostly females (75% of the affected ferrets), is their sterilization at a too young age. For more informations, Go back to homepage
go to the ferret page.







MYTHS AND PARTIAL INFORMATIONS ABOUT STERILIZATION

It is said that an intact dog who won't be allowed to mate will be frustrated : A dog who is not sterilized won't necessarily be frustrated if he doesn't mate. In a dog pack, adolescents dont have the right to mate, and the domination of the leaders have the effect of diminishing sexual desires. It is called, adolescents "marginalization" (10,11).

Some people have their dog sterilized to correct an aggressive behavior : It's helpful in some cases, but dogs who already developped aggressivity won't necessarily be "cured" by sterilization. Usualy vets recommand a chemical castration, which is temporary, in order to see the effects of an eventual sterilization.

Some people believe that it's impossible for an intact dog to be well behaved : Unneutered male dogs who are socialized and trained young won't show any problems. And the fact that owners do obedience training in the house enhances his leadership, and the male dog will respect it and will not mark inside the house (12).







SURGICAL ALTERNATIVES TECHNIQUES

Two surgical techniques are interesting to consider if you wan't to prevent unwanted litters, and prevent unnecessary suffering, without altering the hormonal physiology are vasectomy and tubal liguature. But note that those two techniques won't modify an animal sexual behavior.







REFERENCES:

(1) Hadley, M. E., Endocrinology, 1988, Second Edition, Prentice Hall Englewood, 549 pages

(2) Alberts, B., D. Bray, J. Lewis, M. Raff, K. Roberts and J. D. Watson, Molecular Biology of the Cell, 1983, Garland Publishing, Inc., New York, 1148 pages

(3)The Merck Veterinary Manual, 1991, Seventh edition, Merck and Co., Inc, Rahway, 1832 pages

(4) Gregory S.P., "Developments in the understanding of the pathophysiology of urethral sphincter mechanism in competence in the *****", Br. Vet. J., 1994 Mar;150(2):135-150

(5) Holt P. E. and M. V. Thrusfield, "Association in bitches between breed, size, neutering and docking, and acquired urinary incontinence due to incompetence of the urethral sphincter mechanism", Vet. Rec., 1993 Aug 21;133(8):177-180)

(6) Arnold S., "Urinary incontinence in castrated bitches. Part 1: Significance, clinical aspects and etiopathogenesis", Schweiz Arch Tierheilkd, 1997;139(6):271-276)

(7) Aaron, A., K. Eggleton, C. Power, P. E. Holt, "Urethral sphincter mechanism incompetence in male dogs: a retrospective analysis of 54 cases", Vet. Rec. 1996 Nov 30;139(22):542-546)

(8) Panciera DL., "Hypothyroidism in dogs: 66 cases (1987-1992)", J. Am. Vet. Med. Assoc., 1994, Mar 1;204(5):761-767)

(9) Fogle, B., The Dog's Mind, 1992, Howell Book House, New York, 201 pages and Tucker, M., Solving your dog Problems, 1988, Howell Book House Inc., New York, 146 pages)

(10) Dehasse, J., Le Caniche, 1995, Le Jour Editeur, Montréal, 160 pages

(11) Dehasse, J., Le Doberman, 1995, Le Jour Editeur, Montréal, 156 pages)

(12) Carlson, J. and R. Green, Good Dogs, Bad Habits, 1995, Firside Books, Toronto, 252 pages)

(13) Mulholland SG, SM. Qureshi, RW. Fritz, H. Silverman, Effect of hormonal deprivation on the bladder defense mechanism, J Urol 1982 May;127(5):1010-3

(14) Augsburger, H. R., Cruz-Orive, L. M., "Influence of ovariectomy on the canine striated external urethral sphincter (M. urethralis): a stereological analysis of slow and fast twitch fibres", Urol. Res., 1998, 26(6):417-22

(15) Augsburger, H. R., Cruz-Orive, L. M., "Stereological analysis of the urethra in sexually intact and spayed female dogs", Acta. Anat. (Basel), 1995, 154(2):135-42

(16) Johnston S.D., Kamolpatana K., Root-Kustritz MV., Johnston G. R., "Prostatic disorders in the dog", Anim. Reprod. Sci., 2000, Jul., 2; 60-61: 450-15.

(17) Bell F.W., Klauser J.S., Hayden D.W., Feeney D.A., Johnston S.D., "Clinical and pathologic features of prostatic adenocarcinoma in sexually intact and castrated dogs: 31 cases (1970-1987)

(18) Krawiec D.R., Heflin D., "Study of prostatic disease in dogs: 177 cases (1981-1986)", J. Am. Vet. Med. Assoc., 1992, Apr. 15; 200(8): 1119-22