[gemy]

Other Health Considerations

A number of studies have shown that there is an increase in the incidence offemale urinary incontinence in dogs spayed early (13), although this findinghas not been universal. Certainly there is evidence that ovarian hormones arecritical for maintenance of genital tissue structure and contractility.(14, 15)Neutering also has been associated with an increased likelihood of urethralsphincter incontinence in males.(16) This problem is an inconvenience, and notusually life-threatening, but nonetheless one that requires the dog to bemedicated for life. A health survey of several thousand Golden Retrieversshowed that spayed or neutered dogs were more likely to develophypothyroidism.(2) This study is consistent with the results of another studyin which neutering and spaying was determined to be the most significant gender-associatedrisk factor for development of hypothyroidism.(17) Infectious diseases weremore common in dogs that were spayed or neutered at 24 weeks or less as opposedto those undergoing gonadectomy at more than 24 weeks.(18) Finally, the AKC-CHFreport demonstrated a higher incidence of adverse reactions to vaccines inneutered dogs as compared to intact.(12)

I have gathered these studies to show that our practice of routinely spaying orneutering every dog at or before the age of 6 months is not a black-and-whiteissue. Clearly more studies need to be done to evaluate the effects ofprepubertal spaying and neutering, particularly in canine athletes.

Currently, I have significant concerns with spaying or neutering canineathletes before puberty. But of course, there is the pet overpopulationproblem. How can we prevent the production of unwanted dogs while still leavingthe gonads to produce the hormones that are so important to canine growth anddevelopment? One answer would be to perform vasectomies in males and tuballigation in females, to be followed after maturity by ovariohysterectomy infemales to prevent mammary cancer and pyometra. One possible disadvantage isthat vasectomy does not prevent some unwanted behaviors associated with malessuch as marking and humping. On the other hand, females and neutered malesfrequently participate in these behaviors too. Really, training is the bestsolution for these issues. Another possible disadvantage is finding aveterinarian who is experienced in performing these procedures. Nonetheless,some do, and if the procedures were in greater demand, more veterinarians wouldlearn them.

I believe it is important that we assess each situation individually. Forcanine athletes, I currently recommend that dogs and bitches be spayed orneutered after 14 months of age.

References

Salmeri KR, Bloomberg MS, Scruggs SL, Shille V.. Gonadectomy in immature dogs: effects on skeletal, physical, and behavioral development. JAVMA 1991;198:1193-1203
http://www.grca.org/healthsurvey.pdf
Grumbach MM. Estrogen, bone, growth and sex: a sea change in conventional wisdom. J Pediatr Endocrinol Metab. 2000;13 Suppl 6:1439-55.
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.
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.
Spain CV, Scarlett JM, Houpt KA. Long-term risks and benefits of early-age gonadectomy in dogs. JAVMA 2004;224:380-387.
Ware WA, Hopper DL. Cardiac tumors in dogs: 1982-1995. J Vet Intern Med 1999 Mar-Apr;13(2):95-103
Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters D, Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1434-40
Ru G, Terracini B, Glickman LT. Host related risk factors for canine osteosarcoma. Vet J. 1998 Jul;156(1):31-9.
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
http://www.akcchf.org/pdfs/whitepapers/Biennial_National_Parent_Club_Canine_Health_Confer ence.pdf
Meuten DJ. Tumors in Domestic Animals. 4th Edn. Iowa State Press, Blackwell Publishing Company, Ames, Iowa, p. 575