On neutering, you will be hard pressed to find a vet today that would recommend anything but neutering your pet early in their life, normally around six months. The reasons given are always the same, prevent unwanted babies and long term health benefits including a reduction in cancer.
In male mammals the gonads are the two testes, and in females the gonads are the two ovaries.
The gonads are best known for making gametes (single celled germ cells) which is sperm in males and eggs in females. These two cells then get it on inside the female and make a baby. Most of us have that down pat.
While sex hormones in males and females function largely in the whole “sex” business from conception to baby birth, they also play pivotal roles in the maintenance of body muscle and bone growth.
Neutering or 'spaying' a female animal involves removing the womb and ovaries (an ovaro-hysterectomy). Males are castrated whereby the testicles are surgically removed. This is done before dogs come into puberty (i.e. start producing sex hormones for the first time) which is very approximately 6 months in males and around 9 months in females, though breed and body size play large rolls here. General advice from the majority of veterinary circles is that responsible dog owners neuter at 6m months. In other countries it is much earlier. Both operations are carried out under general anesthetic.
The number one reason for removing the sex hormones is to prevent unwanted breeding, hence folk at the front line of mopping up all our unwanted fur babies are very big fans (www.dspca.ie/SpayorNeuteringYourPetBenefits). The major health benefit constantly cited is to prevent the possible occurrence of testicular cancer, peri-anal cancers and ovarian cancers in dogs and cats. Other reasons often cited is the spread of inferior genetic traits and to reduce problematic behaviour including male-male aggression around females in heat and the roaming behaviour of both males and females when love is in the air.
The early neutering of dogs is not without it's side effects or critics, and I'm certainly one of them. But please, before the heavily stressed and over-worked shelter staff post up about overpopulation problems (I spent a couple of years in them too), lets look at this this issue with less emotion and more science.
If we ignore the fact that gonadal cancers are rare enough in a general population and that dogs recover very well from testicular cancer following diagnosis and castration, by removing the gonads in developing animals you certainly prevent the possible occurrence of gonadal cancers such as testicular and ovarian cancer. However, ironically, while these possible cancers of your pet will be avoided, numerous studies show that removing the sex organs early in the developmental period of an animal causes cancer in your pet, just not in their testes or ovaries.
(Ware and Hopper, 1999, http://www.ncbi.nlm.nih.gov/pubmed/10225598)
(Ru et al. 1998, http://www.ncbi.nlm.nih.gov/pubmed/9691849).
(Cooley et al. 2002, http://www.ncbi.nlm.nih.gov/pubmed/12433723)
Testosterone and estrogen play pivotal roles in the development of your muscles and bones. It stands to reason that if you remove testosterone and estrogen from the vital and dramatic puberty growth phase there will be consequences to that individual's height, muscle mass and bone formation of the individual, compared to an intact animal of the same size and breeding. Studies show this to be absolutely the case.
A study by Stubbs and Bloomberg (1995) set out to answer the following theory: Estrogen tells the growth plates to stop. Thus if you remove the estrogen-producing organs in immature dogs, female and male, you could expect cause growth plates to remain open and the dog to grow longer bones. They divided dogs and cats into three groups. Group one was neutered at 7 wks, group two at 7 months, and group three remained unneutered. They found that “early spay/neuter may result in a slight increase in adult height”. The earlier the spay the taller the dog. Other authors found similar findings (Salmeri et al 1991).
Preston Stubbs, DVM & Mark Bloomberg, DVM Seminars in Vet Med & Surgery, Small Animal, Volume 10, No 1 Feb 1995 Dept of Small Animal Clin Sci, Univ of Florida
Katherine Salmeri, DVM, Mark Bllomber, DVM, Sherry Scuggs, BS, Victor Shille DVM, Journal of American Vet Med Association, Volume 198, No 7 1991
Thus with no estrogen to shut it down, these animals can continue to grow and wind up with abnormal growth patterns and bone structure. This results in irregular body proportions.
A study by the Cornell University's College of Veterinary Medicine and published in the Journal of the American Veterinary Medical Association showed that both male and female dogs sterilized at an early age were more prone to hip dysplasia.
When one organ is removed, others will suffer and spayed and neutered Golden Retrievers are proven to be more likely to develop hypothyroidism.
Panciera DL. Hypothyroidism in dogs: 66 cases (1987-1992). J Am Vet Med Assoc. 1994 Mar 1;204(5):761-7
Glickman L, N Glickman, and R Thorpe. The Golden Retriever Club of America National Health Survey, 1998-1999. Available online athttp://www.grca.org/pdf/health/healthsurvey.pdf
Early neutering increases the risk of urinary incontinence by 4-20%
Very early neutering increases the risk of disease in dogs. A study of shelter dogs conducted by the College of Veterinary Medicine at Texas A&M University concluded that infectious diseases were more common in dogs that were sterilized at less than 24 weeks of age.
I can't find a study to verify this, I can only testify to what groomers are repeatedly telling us, that desexed dogs have very wooly coats, commonly called “spay coat”. It seems to be an overproduction of the undercoat but until more is knows, this is annecdotal.
Dr. Karen Becker is now a famous veterinary advocate for more thought to be brought back in to the dog world. Her youtube video last year on neutering and article on same subject gave me the bones of this article. The video received an enormous amount of support but also scathing criticism. Since then Dr. Becker has released another video on the subject explaining her thoughts on the whole affair. She breaks down in the middle of it when she thinks about the number of animals she has harmed with her previous advice. Worth a watch.
Let me know what you think?