German Shepherd Dogs: The Impacts of Early Neutering
Generations of veterinarians in the United States have been taught to recommend neutering for dogs between four to six months of age, and certainly before their first birthday. Relatively recent research has revealed compelling negative implications of such “early neutering” in Golden Retrievers, Labradors, Vizslas, and Rottweilers. Now, along comes more compelling research, this time pertaining to German Shepherd dogs.
German Shepherd research
It’s difficult to find a dog more loyal and intelligent than a well-bred German Shepherd. It’s also difficult to find a breed more prone to joint maladies. Recently published research out of the University of California, Davis explored the impacts of early neutering on the incidence of joint diseases, various cancers, and urinary incontinence (involuntary urine leakage) in this breed.
Medical records from 1170 neutered and intact (not neutered) purebred German Shepherds were retrospectively evaluated throughout the first eight years of the dogs’ lives. The records were investigated for the incidence of joint disorders (hip dysplasia, elbow dysplasia, cruciate ligament disease), various types of cancer (osteosarcoma, lymphoma, hemangiosarcoma, mast cell cancer, mammary cancer), and urinary incontinence.
Joint diseases: The incidence of one or more joint disorders was significantly higher in male shepherds castrated before one year of age (21% of dogs) compared to the intact male population (7% of dogs). Females spayed before one year of age also had an increased incidence of joint disease (16%) compared to their intact counterparts (5%). Of all the joint disorders the incidence of cruciate ligament disease increased the most in proportion to early neutering.
Cancer: Mammary cancer (breast cancer) was diagnosed in 4% of intact female shepherds compared with an incidence of less than 1% in dogs spayed before one year of age. No significant differences in the incidence of the other cancer types studied were discovered when intact and neutered shepherds were compared.
Urinary incontinence: The incidence of incontinence in intact females was 0%. Amongst the population spayed before 6 months of age, the incidence was 4.7%, and for those neutered between 6 and 11 months, the incidence was 7.3%. The average age of onset of incontinence was 5.2 years.
The increased incidence of joint disease in early-neutered German Shepherds resembles data collected on Golden Retrievers, Labradors, and Vizslas. The theory behind this association relates to closure of growth plates, the regions within bones that promote lengthening. When reproductive hormones arrive on the scene (puberty), they signal the growth plates to close, and lengthening of bones ceases. When a dog is neutered prior to the onset of puberty, the growth plates don’t receive this signal and the bones continue to lengthen. It is theorized that this excess lengthening disrupts normal joint alignment that, in turn, causes joint disorders later in life.
The increase in mammary cancer in intact females in this study aligns with other research results. Interestingly, the effect of early neutering on the incidences of the other cancers studied vary significantly compared to what has been learned about the impact of early neutering in Golden Retrievers, Vizslas, and Rottweilers. In these breeds, early neutering is associated with dramatic increases in multiple types of cancer. These differences are fascinating and underscore the value of performing breed-specific research.
The increased incidence of urinary incontinence in early neutered dogs isn’t surprising. This association has been demonstrated in a number of previous studies.
I can think of multiple occasions throughout my professional career when new information has prompted me to question what I’d been taught to be the “norm” in veterinary practice. All of the research to date pertaining to the impacts of early neutering has caused me, and hopefully plenty of other veterinarians, to question the standard recommendation to neuter dogs before one year of age.
What about your dog?
Is it reasonable to extrapolate the results from any of this breed-specific research to your dog? I don’t know the answer to this question, but do encourage you to discuss it with your veterinarian before your dog is automatically neutered prior to his or her first birthday.
I have a “granddog” named Fisher. He’s a super lovable, kind of goofy, large, mixed-breed dog who wasn’t neutered prior to his adoption from a shelter (surprising given that most shelters insist on this). I encouraged my son to postpone neutering Fish until he reached after first birthday. My thinking was that neutering later rather than earlier might prevent future joint maladies. My son’s last dog, a fabulous Hurricane Katrina rescue named Tipper, experienced torn cruciate ligaments in both knees! Mr. Fish was neutered just last week, a couple of months after his first birthday.
I present all of the information above with the caveat (and my strong personal belief) that prevention of unplanned litters of puppies should trump all other considerations. If a dog cannot be responsibly supervised, neutering before the onset of sexual maturity is a clear first choice.
Is your dog neutered? If so, at what age was the surgery performed?
Nancy Kay, DVM
Diplomate, American College of Veterinary Internal Medicine
Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
Author of Your Dog’s Best Health: A Dozen Reasonable Things to Expect From Your Vet
Recipient, Leo K. Bustad Companion Animal Veterinarian of the Year Award
Recipient, American Animal Hospital Association Animal Welfare and Humane Ethics Award
Recipient, Dog Writers Association of America Award for Best Blog
Recipient, Eukanuba Canine Health Award
Recipient, AKC Club Publication Excellence Award
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Please visit http://www.speakingforspot.com to read excerpts from Speaking for Spot and Your Dog’s Best Health. There you will also find “Advocacy Aids”- helpful health forms you can download and use for your own dog, and a collection of published articles on advocating for your pet’s health. Speaking for Spot and Your Dog’s Best Health are available at http://www.speakingforspot.com