Here is some info I pulled from my files. I can't seem to undo the "underlines" on this, sorry.
Hope this helps,
Dr. Karen Becker: “If you decide to spay your dog, holding off on the surgery until she is sexually mature and fully mentally and physically developed can help protect her against many forms of cancers and endocrine diseases later on.” Pyometra: More Than a Uterine Infection
As a veterinary oncologist and founder of the pet hospice program Pawspice, Dr. Villalobos concedes, “It is earth shattering to consider that some of the cancers we have been battling may have been enhanced by early neutering instead of the reverse.”
Page 2 of 12: http://www.naiaonline.org/pdfs/LongT...uterInDogs.pdf
“The evidence shows that spay/neuter correlates with both positive AND adverse health effects in dogs.
It also suggests how much we really do not yet understand about this subject. On balance, it appears that no compelling case can be made for neutering most male dogs, especially immature male dogs, in order to prevent future health problems. The number of health problems associated with neutering may exceed the associated health benefits in most cases.
On the positive side, neutering male dogs
•eliminates the small risk (probably <1%) of dying from testicular cancer
•reduces the risk of non-cancerous prostate disorders
•reduces the risk of perianal fistulas
•may possibly reduce the risk of diabetes (data inconclusive)
On the negative side,
neutering male dogs
•if done before 1 year of age, significantly increases the risk of osteosarcoma (bone cancer); this is a common cancer in medium/large and larger breeds with a poor prognosis.
•increases the risk of cardiac hemangiosarcoma
by a factor of 1.6
•triples the risk of hypothyroidism
•increases the risk of progressive geriatric cognitive impairment
•triples the risk of obesity, a common health problem in dogs with many associated health problems
•quadruples the small risk (<0.6%) of prostate cancer
•doubles the small risk (<1%) of urinary tract cancers
•increases the risk of orthopedic disorders
•increases the risk of adverse reactions to vaccinations"
"There is a growing body of scientific evidence that points to the harmful effects of spaying and neutering: shortened life span, increased risk of certain cancers
, and increased incidence of ACL injuries. Depending on your situation, you may wish to delay the spaying or neutering of your dog until it is 14 months old or not sterilize it at all.
If you're worried about not being able to control your dog when it becomes sexually mature, consider a vasectomy or tubal ligation, which will prevent your dog from becoming a parent, but retain the beneficial effects of the dog's sex hormones." Ted Kerasote
Dr. Becker: http://healthypets.mercola.com/sites/healthypets/archive/2013/09/30/neutering-health-risks.aspx?e_cid=20130930Z1_PetsNL_art_1&utm_sourc e=petnl_RTLUBIQ&utm_medium=email&utm_content=art1& utm_campaign=20130930Z1RTLUBIQ