THE SECOND WIND GERMAN SHEPHERDS

Subtitle

Below are several very important articles on spaying and Neutering. Please read.

 

 

By Jennifer Viegas
 

Spaying is a procedure few of us question. This year alone, thousands of female dogs will undergo the hysterectomy operation, which removes the ovaries and uterus. Chances are your own pet has already undergone these removals.

A groundbreaking new study, however, may change the way we view this common surgery.

Longevity and Ovaries Linked

Women tend to live longer than men do, but did you know this life span edge holds true for female dogs too? "Like women, female dogs in our study had a distinct survival advantage over males," according to project leader Dr. David Waters, Ph.D., a veterinarian, director of the Gerald P. Murphy Cancer Foundation and associate director of Purdue University's Center on Aging and the Life Course.

Nevertheless, female dogs do not always reach the same age. That became obvious when Waters and his team studied information on the oldest living pet dogs in the United States. (Data on these canine seniors is tracked by the Center for Exceptional Longevity Studies.) Waters had a nagging suspicion: "We think that ovaries are part of a system that impacts longevity and perhaps the rate of aging."

To test out the theory, Waters, who is also a professor in the department of veterinary clinical sciences at Purdue, and his team analyzed 119 rottweiler "centenarians," which were elderly dogs that survived to 13 years. That's 30 percent longer than the life span of most breed members. "We found that female rottweilers that kept their ovaries for at least six years were four times more likely to reach exceptional longevity compared to females who had the shortest lifetime ovary exposure."

Yet another study, on more than 29,000 women, came to a similar conclusion. Dr. William Parker of the John Wayne Cancer Institute in Santa Monica, Calif., led that research. "For the last 35 years, most doctors have been routinely advising women undergoing hysterectomy to have their ovaries removed to prevent ovarian cancer," he said. "We believe that such an automatic recommendation is no longer warranted."

Important to Weigh the Pros and Cons

When it comes to longevity, Waters, Parker and their colleagues believe it's worth it for a female to keep her ovaries. Women who retain their ovaries for at least 50 years often live longer than women who don't, according to the new findings. For dogs, the comparable age for keeping the ovaries intact, at least for large breeds like rottweilers, is about 6 or 7 years.

Waters is quick to point out that all women and dog owners should weigh the pros and cons of keeping ovaries and should initiate an informed discussion on the upside and downside with their doctor and their pet's veterinarian.

The Benefits of Spaying

Linda Lasky, a registered veterinary technician at Montclair Veterinary Hospital in Oakland, Calif., said she is not aware of any veterinary hospital that performs a partial hysterectomy on dogs. Owners must therefore choose between three options:

  1. Do not have the dog spayed.
  2. Spay the dog after she is at least 6 years old.
  3. Spay the dog before she reaches puberty, which is the commonly accepted practice.

Lasky strongly recommends the third option, which she said helps prevent two potentially fatal health problems: mammary tumors and pyometra, a canine uterine infection. Spaying also prevents certain behavioral problems related to dogs going into heat. The most obvious benefit of spaying is that it curbs canine overpopulation.

Other Ways of Extending Your Dog's Life

Through his Gerontology Training Program for DVMs, Waters works with veterinarians to address the findings about ovaries and other longevity matters. He says participants in the program also "emerge as effective educators of pet owners on issues pertaining to lifestyle choices that promote healthy longevity."

Lasky agrees that lifestyle choices, such as what owners feed their dogs and how they care for them, can also make a huge difference in the quality and length of their pets' lives. Over the years, she's noticed that "companion animals are living longer and longer" due to improved medical help, quality nutrition, and love and care provided by owners. Therefore, while retention of ovaries remains a hotly debated issue, spayed dogs may still have a chance at earning a coveted spot in the oldest canines database at the Center for Exceptional Longevity Studies.

Copyright (c) 2010 Studio One Networks. All rights reserved.

Jennifer Viegas is the managing editor of The Dog Daily. She is a reporter for Discovery News, the news service for the

Early Spay -Neuter Considerations

Early Spay-Neuter Considerations for the Canine Athlete

One Veterinarian’s Opinion

© 2005 Chris Zink DVM, PhD, DACVP

www.caninesports. com

Those of us with responsibility for the health of canine athletes need to continually read and evaluate new

scientific studies to ensure that we are taking the most appropriate care of our performance dogs. This article

provides evidence through a number of recent studies to suggest that veterinarians and owners working with

canine athletes should revisit the standard protocol in which all dogs that are not intended for breeding are

spayed and neutered at or before 6 months of age.

Orthopedic Considerations

A study by Salmeri et al in 1991 found that bitches spayed at 7 weeks grew significantly taller than those spayed

at 7 months, who were taller than those not spayed (or presumably spayed after the growth plates had closed).(1)

A study of 1444 Golden Retrievers performed in 1998 and 1999 also found bitches and dogs spayed and

neutered at less than a year of age were significantly taller than those spayed or neutered at more than a year of

age.(2) The sex hormones, by communicating with a number of other growth-related hormones, promote the

closure of the growth plates at pubjerty (3), so the bones of dogs or bitches neutered or spayed before puberty

continue to grow. Dogs that have been spayed or neutered well before puberty can frequently be identified by

their longer limbs, lighter bone structure, narrow chests and narrow skulls. This abnormal growth frequently

results in significant alterations in body proportions and particularly the lengths (and therefore weights) of certain

bones relative to others. For example, if the femur has achieved its genetically determined 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 likely becomes heavier (because it is longer), and may cause increased stresses on the

cranial cruciate ligament. In addition, sex hormones are critical for achieving peak bone density.(4) These

structural and physiological alterations may be the reason why at least one recent study showed that spayed and

neutered dogs had a higher incidence of CCL rupture.(5) Another recent study showed that dogs spayed or

neutered before 5 1/2 months had a significantly higher incidence of hip dysplasia than those spayed or neutered

after 5 1/2 months of age, although it should be noted that in this study there were no standard criteria for the

diagnosis of hip dysplasia.(6) Nonetheless, breeders of purebred dogs should be cognizant of these studies and

should consider whether or not pups they bred were spayed or neutered when considering breeding decisions.

Cancer Considerations

A retrospective study of cardiac tumors in dogs showed that there was a 5 times greater risk of

hemangiosarcoma, one of the three most common cancers in dogs, in spayed bitches than intact bitches and a

2.4 times greater risk of hemangiosarcoma in neutered dogs as compared to intact males.(7) A study of 3218

dogs demonstrated that dogs that were neutered before a year of age had a significantly increased chance of

developing bone cancer.(8) A separate study showed that neutered dogs had a two-fold higher risk of developing

bone cancer.(9) Despite the common belief that neutering dogs helps prevent prostate cancer, at least one study

suggests that neutering provides no benefit.(10) There certainly is evidence of a slightly increased risk of

mammary cancer in female dogs after one heat cycle, and for increased risk with each subsequent heat. While

about 30 % of mammary cancers are malignant, as in humans, when caught and surgically removed early the

prognosis is very good.(12) Luckily, canine athletes are handled frequently and generally receive prompt

veterinary care.

Behavioral Considerations

The study that identified a higher incidence of cranial cruciate ligament rupture in spayed or neutered dogs also

identified an increased incidence of sexual behaviors in males and females that were neutered early.(5) Further,

the study that identified a higher incidence of hip dysplasia in dogs neutered or spayed before 5 1/2 months also

showed that early age gonadectomy was associated with an increased incidence of noise phobias and

undesirable sexual behaviors.(6) A recent report of the American Kennel Club Canine Health Foundation reported

significantly more behavioral problems in spayed and neutered bitches and dogs. The most commonly observed

behavioral problem in spayed females was fearful behavior and the most common problem in males was

aggression.(12)

Other Health Considerations

A number of studies have shown that there is an increase in the incidence of female urinary incontinence in dogs

spayed early (13), although this finding has not been universal. Certainly there is evidence that ovarian hormones

are critical for maintenance of genital tissue structure and contractility. (14, 15) Neutering also has been

associated with an increased likelihood of urethral sphincter incontinence in males.(16) This problem is an

inconvenience, and not usually life-threatening, but nonetheless one that requires the dog to be medicated for life.

A health survey of several thousand Golden Retrievers showed that spayed or neutered dogs were more likely to

develop hypothyroidism.(2) This study is consistent with the results of another study in which neutering and

spaying was determined to be the most significant gender-associated risk factor for development of

hypothyroidism. (17) Infectious diseases were more common in dogs that were spayed or neutered at 24 weeks or

less as opposed to those undergoing gonadectomy at more than 24 weeks.(18) Finally, the AKC-CHF report

demonstrated a higher incidence of adverse reactions to vaccines in neutered dogs as compared to intact.(12)

I have gathered these studies to show that our practice of routinely spaying or neutering every dog at or before

the age of 6 months is not a black-and-white issue. Clearly more studies need to be done to evaluate the effects

of prepubertal spaying and neutering, particularly in canine athletes.

Currently, I have significant concerns with spaying or neutering canine athletes before puberty. But of course,

there is the pet overpopulation problem. How can we prevent the production of unwanted dogs while still leaving

the gonads to produce the hormones that are so important to canine growth and development? One answer

would be to perform vasectomies in males and tubal ligation in females, to be followed after maturity by

ovariohysterectomy in females to prevent mammary cancer and pyometra. One possible disadvantage is that

vasectomy does not prevent some unwanted behaviors associated with males such as marking and humping. On

the other hand, females and neutered males frequently participate in these behaviors too. Really, training is the

best solution for these issues. Another possible disadvantage is finding a veterinarian who is experienced in

performing these procedures. Nonetheless, some do, and if the procedures were in greater demand, more

veterinarians would learn them.

I believe it is important that we assess each situation individually. For canine athletes, I currently recommend that

dogs and bitches be spayed or neutered after 14 months of age.

References:

1. Salmeri KR, Bloomberg MS, Scruggs SL, Shille V.. Gonadectomy in immature dogs: effects on skeletal,

physical, and behavioral development. JAVMA 1991;198:1193- 1203

2. http://www.grca. org/healthsurvey .pdf

3. Grumbach MM. Estrogen, bone, growth and sex: a sea change in conventional wisdom. J Pediatr Endocrinol

Metab. 2000;13 Suppl 6:1439-55.

4. Gilsanz V, Roe TF, Gibbens DT, Schulz EE, Carlson ME, Gonzalez O, Boechat MI. Effect of sex steroids on

peak bone density of growing rabbits. Am J Physiol. 1988 Oct;255(4 Pt 1):E416-21.

5. 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.

6. Spain CV, Scarlett JM, Houpt KA. Long-term risks and benefits of early-age gonadectomy in dogs. JAVMA

2004;224:380- 387.

7. Ware WA, Hopper DL. Cardiac tumors in dogs: 1982-1995. J Vet Intern Med 1999 Mar-Apr;13(2) :95-103

8. Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters D, Cancer Epidemiol Biomarkers

Prev. 2002 Nov;11(11):1434- 40

9. Ru G, Terracini B, Glickman LT. Host related risk factors for canine osteosarcoma. Vet J. 1998 Jul;156(1):31-

9.

10. Obradovich J, Walshaw R, Goullaud E. The influence of castration on the development of prostatic carcinoma

in the dog. 43 cases (1978-1985). J Vet Intern Med 1987 Oct-Dec;1(4) :183-7

11. http://www.akcchf. org/pdfs/ whitepapers/ Biennial_ National_ Parent_Club_ Canine_Health_ Conference. pdf

12. Meuten DJ. Tumors in Domestic Animals. 4th Edn. Iowa State Press, Blackwell Publishing Company, Ames,

Iowa, p. 575

13. Stocklin-Gautschi NM, Hassig M, Reichler IM, Hubler M, Arnold S. The relationship of urinary incontinence to

early spaying in bitches. J. Reprod. Fertil. Suppl. 57:233-6, 2001

14. Pessina MA, Hoyt RF Jr, Goldstein I, Traish AM. Differential effects of estradiol, progesterone, and

testosterone on vaginal structural integrity. Endocrinology. 2006 Jan;147(1):61- 9.

15. Kim NN, Min K, Pessina MA, Munarriz R, Goldstein I, Traish AM. Effects of ovariectomy and steroid

hormones on vaginal smooth muscle contractility. Int J Impot Res. 2004 Feb;16(1):43- 50.

16. Aaron A, Eggleton K, Power C, Holt PE. Urethral sphincter mechanism incompetence in male dogs: a

retrospective analysis of 54 cases. Vet Rec. 139:542-6, 1996

17. Panciera DL. Hypothyroidism in dogs: 66 cases (1987-1992). J. Am. Vet. Med. Assoc., 204:761-7 1994

18. Howe LM, Slater MR, Boothe HW, Hobson HP, Holcom JL, Spann AC. Long-term outcome of gonadectomy

performed at an early age or traditional age in dogs. J Am Vet Med Assoc. 2001 Jan 15;218(2):217- 21

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