"Like women, female dogs in our study had a distinct survival advantage over males," said the lead researcher David J. Waters, associate director of Purdue University's Center on Aging and the Life Course and a professor in the Department of Clinical Sciences. "But taking away ovaries during the first four years of life completely erased the female survival advantage. 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."
Because death from cancer is so prevalent in rottweilers, researchers conducted a subgroup analysis of only dogs that did not die of cancer. This focused research further proved the strong association between intact ovaries and longevity.
Even in dogs that did not die of cancer, the female rotties that kept their ovaries the longest were nine times more likely to achieve exceptional longevity (13+ years).
Simply put, study results indicate removal of a dog’s ovaries significantly increases the risk for a major lethal disease.
Interestingly, the rottweiler research lines up with findings from another recent study of women who had undergone hysterectomies. In that study, women who lost their ovaries prior to age 50 were at greater risk of death by causes other than breast, ovarian and uterine cancer than women who kept their ovaries until age 50.
A judgment about when and if you spay/neuter should be based on the breed of your pet, the diet you feed, and its physical, immunological and mental development. There is no universal age that is best for spaying … I firmly believe each dog should be individually evaluated to determine when this procedure should be done.
The timing of the surgery should be decided with the help of your holistic veterinarian and input from other seasoned dog owners or breeders.
Methods of Sterilization
There are actually three different surgeries which can render a female dog sterile:
- Spaying, also known as ovariohysterectomy
- Hysterectomy in which only the uterus is removed
- Tubal ligation
Spaying is by far the most common of the three options. This surgery removes the entire female reproductive tract, including ovaries, oviducts, uterine horns and the uterus. Spaying eliminates the source of the hormones progesterone and estrogen and prevents your dog from having twice-yearly heat cycles.
A hysterectomy removes the uterus but leaves the ovaries.
In a tubal ligation, the oviducts are cut and tied off, preventing ova from getting to the uterus or coming in contact with sperm.
Neither hysterectomy nor tubal ligation shuts off hormone production, so your dog will continue to go into heat and can mate with male dogs, but no pregnancy will result.
These latter two methods of sterilization are traditionally much less popular than spaying among both veterinarians and dog owners.
Neutering of male dogs, also known as castration involves surgical removal of both testicles, halting production of both sperm and testosterone. It’s possible to perform a vasectomy on a male dog as an alternative to castration, however, like hysterectomies and tubal ligations for female dogs, it is very rarely done.
The Argument for Spaying and Neutering
An intact female runs the risk pregnancy. Unplanned pregnancies result in unwanted litters of puppies (and kittens), many of which end up as abused, neglected, or abandoned animals.
The crisis of pet overpopulation is a serious one, and it is generally assumed responsible pet owners, animal shelters and rescue organizations will spay or neuter animals in their care to help combat the problem.
Pet owners spay or neuter not only for birth control, but also for reasons of convenience and to reduce or eliminate certain future health concerns.
Spaying of female dogs eliminates the inconvenience and hygiene challenges associated with heat cycles. You don’t have to worry that your spayed dog will try to escape your home in order to mate, and you don’t have to concern yourself with male dogs around your female.
Spaying also removes the potential for false pregnancies and life-threatening uterine infections (called pyometras), and reduces the risk of estrogen-related mammary cancer and tumors of the reproductive tract.
A neutered male dog is less apt to roam or mark his territory anywhere and on everything. He also shows less interest in female dogs in heat. Neutering also removes the risk of testicular tumors, perineal hernias and enlarged prostate glands.
Health Problems Associated with Gonad Removal
Common sense tells us, and research proves there are a number of health benefits associated with the sex hormones (estrogen, progesterone, testosterone) produced by ovaries and testicles. These advantages vary with the age, gender and breed of each animal.
Halting production of these hormones through spaying and neutering has been found to increase the risk of certain specific diseases and conditions in dogs, including:
- Hemangiosarcoma, a highly malignant form of cancer, osteosarcoma (bone cancer), and transitional cell carcinoma (bladder cancer), both sexes
- Prostatic cancer in male dogs
- Autoimmune thyroiditis and hypothyroidism, both sexes
- Urinary incontinence and urinary tract infections in females
- Obesity, both sexes
- Endocrine dysfunction, adrenal disease
Sterilization Decisions Should Be a Part of a Holistic Approach to Your Pet’s Health and Quality of Life
My professional opinion is there is no one perfect, magic age at which to spay or neuter every pet.
Your dog should be old enough to be considered balanced both physically and mentally. Generally speaking, this balance isn’t achieved until a dog has reached at least one year of age. Although some breeds reach maturity faster than others, many giant breed dogs are still developing at 2 years of age.
Other considerations include your dog’s breed and gender, diet, level of exercise, behavioral habits, previous physical or emotional trauma, existing health concerns, and overall lifestyle.
If you own an intact animal and need to make a spay/neuter decision, I encourage you to first learn all you can about surgical sterilization options and the risks and benefits associated with the procedures.
Talk with reputable breeders and other experienced dog owners, and consult a holistic veterinarian to understand what steps you can take to insure the overall health and longevity of your pet.