Buyers often assume their pet dogs should be surgically neutered

Buyers often assume their pet dogs should be surgically neutered. If the decision to neuter a male is made, there is now a reliable, less costly injectable alternative. HOWEVER...you should also know that recent research at Purdue Vet School indicates that neutering increases the risk that your canine will develop cancer by 50%. Think carefully!!! —Lynnel Jones, AndalusianBullmastiffs.com

Addressing the Testosterone Issue

Testosterone plays a role in modulating certain behaviors such as roaming, urine marking in-doors, sexual mounting and aggression toward other dogs (versus playful activity or dominance). Neutersol reduces the male hormone, testosterone, by 41-52% while surgical castration reduces testosterone by 95%. These behaviors may persist after either neutering method.

While testosterone plays a role in affecting certain sexually dimorphic behaviors, it is not the only factor. In fact, the veterinary behavioral textbooks point out that there are multiple contributing factors with regard to these behaviors. Surgical castration does not completely eliminate these behaviors. The controlled scientific studies that have assessed the effects of surgical castration with regard to behavior have shown that most dogs continue exhibiting these behaviors. Aggression toward humans shows little significant effect after surgical castration. Surgery can have an effect in some of these, but is far from absolute. The FDA has reviewed the data for both surgery and Neutersol and included wording in the prescribing information of Neutersol addressing this fact, "As with surgical castration, secondary male characteristics (roaming, marking, aggression and mounting) may persist."

Dispelling Testicular Cancer Concerns

Testicular cancers are rare to begin with. Male dogs have a lifetime prevalence of 0.9% of testicular cancers. Most of the time these are benign and/or microscopic and not problematic. Neutersol produces atrophy of the seminiferous tubule which contain the 2 cell types responsible for 2 of the 3 most prevalent testicular cancers, Sertoli cell tumor and seminoma. This action raises the question: if there are no cells to develop the cancer, what is the likelihood of it occurring?

Actually, the highest prevalence of testicular cancers occurs in dogs that have undescended testicles (cryptorchid). Neutersol is not indicated in puppies with this condition. Given a 0.9% testicular cancer rate among male dogs, minus most of those because they prove to be benign and non-problematic, reduced further by atrophy of cell types responsible for cancer of the testes, and finally eliminating the subset of patients most likely to develop testicular tumors (cryptorchids), would result in a very low, virtually insignificant rate of testicular cancer.

Veterinarians presented with this information have concluded the perceived risk of this cancer is not a concern.

Correcting Inaccurate Prostrate Cancer and Enlargement Perceptions

Veterinarians who graduated more than 10 years ago were taught that prostate cancer is more present in intact dogs than castrated dogs. Prostate cancer is actually more common in castrated dogs than intact ones. Contemporary veterinary textbooks and peer reviewed literature stress that prostate cancer in dogs is hormonally independent and that
castrated dogs have shown up to a four times greater risk of developing prostate cancer than intact dogs.

The inaccuracy likely began because there was no data in dogs 30 years ago before the advocacy of spay/neutering. In the absence of that data, veterinary practitioners borrowed data from human medicine. As it is well known now, significant differences exist between the human and canine species. As a result, veterinarians have to set aside prostate cancer as a concern with Neutersol versus surgical castration.

The enlargement of the prostate due to benign prostatic hyperplasia (BPH) as dogs age raises a concern among veterinarians This enlargement can lead to secondary problems and is testosterone dependent. An enlarging prostate pushes on other organs, such as the colon, and disrupts their function, making it difficult to have a bowel movement.

Two important things to keep in mind here. One, although nearly 100% of intact male dogs past the age of nine will have an enlarged prostate, only 1.5% of male dogs will present with symptoms due to that enlargement.

Secondly, when the prostate in aging men enlarges, it grows inward impinging upon the urethra and making it difficult to urinate. In dogs, the prostate enlarges outward to push against the colon, with significantly more expansion room outward, which explains the lower prevalence of developing secondary urinary problems in canines.

The real issue to consider, though, is that Neutersol actually shrinks the prostate significantly. Two years post-injection, Neutersoled dogs had a 52% smaller prostate on average then the control dogs. Even if the prostate stays its normal size, or grows slightly, secondary problems are not likely to develop. Neutersol goes even further to reduce this likelihood by significantly shrinking the prostate.

Towards New Understandings

Undoing commonly held beliefs is not an easy task, but history and science have shown that we do not live on a flat planet. Though the first scientists to proclaim otherwise were labeled heretics, we sometimes find that today's heretics are tomorrow's prophets.

Supported by science, more accurate and up-to-date findings replace these common misconceptions and myths concerning neutering's effects, be it surgical or by injection. In presenting neutering choices to clients for their puppies, veterinarians can be confident that Neutersol virtually eliminates the puppy's surgical risks with the same net effect while ensuring the comfort and same-day return home with the owner.

Fresh thinking and openness to new technology works to the clients' benefit and positions the veterinarian as an informed guardian of their pets' health.

Don P. Polley, DVM, is Director of Veterinary Services, Neutersol with Addison Biological Laboratory. Inc., based in Fayette, Missouri. He was President and Chief-of-Staff of Harvester Animal Clinic, St. Charles, Missouri, and is an author, lecturer, and consultant on Practice Management. He recently served as Director of Veterinary Services, Emergency Animal Rescue Service, United Animal Nations. He can be reached at 1-800-331-2530.