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 pyometra (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 bitch 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 bitch, she's not mature physically and emotionally. Testosterone and estrogen 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 developing 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 develop benign prostatic hypertrophy. But neutered dogs would have a higher  risk of developing 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).

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).

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 bitch", 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;

There is considerable evidence supported by veterinary journal articles and references that draw attention to spay induced incontinence. Also of interest is the standby replacement that was marketed to control this: DES and Penylpropanolamine are no longer on the market, or may not be soon.

Here is some info along with some numbers, quotes and references and some on early altering
 http://www.danesonline.com/earlyspayneuter.htm
 http://www.vet4petz.com/articles/urinary_incontinence.htm
 http://www.research-projects.unizh.ch/vet/unit50100/area110/p2730.htm
 http://www.petloverspublications.com/oc/EarlySpayNeuter.htm
 http://www.petorphans.com/earlyneut/earlyneut.html
 http://www.warrickhumane.com/juvenile.html

 And here are some more articles and some fact sheets about early spay  and neuter:
 http://infoweb.magi.com/~cfhs/fact.htm
 http://www.rallyobedience.com/early.htm
 http://www.cvm.uiuc.edu/ceps/ivb/spay-neu.htm
 http://hometown.aol.co.uk/puddle321/solvingIncontinenceinapetdog.html
 

 "So our vet said he wanted to try her on a drug called Propaline.  This drug is used primarily for bitches who become incontinent after
 spaying."

 http://www.inkabijou.co.uk/incontinence.htm
Jjuhen incontinence results from loss of urethral sphincter tone, the disorder is known as sphincter incompetence. The causes of sphincter incompetence are unclear. The disorder can occur in male and female dogs of any age or breed. The most striking feature of urethral sphincter incompetence, however, is that the overwhelming majority of cases are spayed bitches.

 http://www.pets4life.com/art8.html
Some breeds, such as Dobermans, commonly suffer from what has been termed "spay incontinence," which begins sometime after the spay surgery.  There is no "usual" time period between the surgery and the onset of incontinence symptoms. Neither does there seem to be any link between the age of the dog when spayed, and the onset of symptoms
 

ttp://www.herbal-treatments.com.au/newsletter_18052002_treating_canine_inco
The most common cause of structural incontinence, which develops in a bitch which had not previously had problems. is spay incontinence. This can develop from few months to years after spaying. Otherwise for both sexes, it would be structural changes resulting from a history of severe urinary tract infections.
 
 
 
 

 Last Modified: December, 2002
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