Spaying and neutering (sometimes collectively referred to as speutering or de-sexing) is the sterilization of a dog or cat. Spaying typically refers to the surgical removal of a female animal’s ovaries and uterus (ovariohystorectomy) and neutering refers to the surgical removal of a male animal’s testes (castration). An animal retaining it’s sex organs is “intact” or “unaltered.” In some cases, spaying and neutering is performed in response to a specific health concern, but most often it is done to ensure an animal is unable to reproduce.
Nowadays, routine de-sexing is widely believed to be imperative to responsible dog ownership. By removing any possibilities for reproduction, you’re ensuring that your dog does not contribute to the unwanted pet population. As veterinarians bear witness to the most gut-wrenching consequences of pet overpopulation, including the euthanasia of healthy animals, spaying and neutering is the singlemost common procedure performed in American veterinary hospitals, and the American Veterinary Medical Association has described speutering as “an article of faith within the veterinary community: “thou shalt spay or castrate cats and dogs.””(1)
Having been involved in rescue, I certainly appreciate the valuable role speutering plays in diminishing the number of unwanted animals. I also, however, challenge the notion that it is an imperative to responsible pet stewardship and should thus be automatic. While generally quite safe, speutering is an elective surgery resulting in the permanent and irreversible removal of organs and hormones. I do not begrudge anyone who chooses to speuter their pet, but as the majority of available information is biased towards routine speutering and suggests no reasonable alternative, I seek to offer some additional considerations to inform your choice . . .
• While speutering is widely promoted as beneficial to your dog’s health, there are also health risks. A summary of health considerations follows is included below. Please note: low subject numbers for these studies offers limited statistical reliability and many studies are often biased towards a result. The takeaway is that there is evidence of both risks and benefits.
• Sex organs have many functions beyond reproduction. Chief among them is the production of hormones. Androgens play a role in musculoskeletal development. Estrogen can influence the urinary tract, heart, bones, skin, hair, mucous membranes, pelvic muscles, and brain.
• The notion that automatic speutering is imperative to responsible pet ownership is a largely American phenomenon. Most European countries see less than 10% of their dogs speutered, and Norwegian law bans routine speutering (along with other elective procedures). In the US, ownership and maintenance of an intact animal carries a stigma of irresponsibility while, in Europe, the opposite is true. It should also be noted that these European countries have a nearly non-existent unwanted pet population, suggesting a large cultural component to pet overpopulation.
• Spaying and neutering may change your dog’s behavior for the better. Or, it may not. Neutering has been demonstrated to reduce mounting, roaming, and marking behaviors. However, all of these behaviors are easily addressed through proper rearing, behavior modification, and common sense practice (ie - contain your dog if he’s going to roam!). Contrary to popular belief, neutering has not been demonstrated to provide meaningful reduction in aggression behaviors and, in female dogs, spaying has been demonstrated to increase aggression.(2) There is also some research suggesting that neutering can increase anxiety and cognitive disfunction (doggy alzheimers).(3)
• Navigating the modern dog world with an intact dog can prove challenging. In the cities and suburbs, many speutered dogs have never met an intact dog so find them very unsettling upon first sniff. As a result, intact dogs are often bullied. Boarding facilities often refuse to board intact dogs. And because the modern dog culture perceives speutering as necessary to responsible dog stewardship, your friends, neighbors, veterinarian, etc. may perpetually question your decision to maintain an intact dog.
• Intact dogs can reproduce, and their instincts tell them to do so. In the case of an intact female, she will typically cycle into season once every 6-10 months. During her season she may drip blood for 1-2 weeks, and she will be fertile for 4-5 days towards the end of her cycle. She may exhibit minor changes in behavior associated with hormones before or after her heat cycle. Male dogs can smell when a local female is in season and will sometimes seek her out. Male dogs may also tend towards increased sexual behaviors.
• Unwanted and unintended breedings absolutely happen, especially if you house intact males and females together. While a female dog is typically only fertile for 8-10 days every year, a door or gate accidentally left open during that time can result in a large litter of puppies. Some female dogs can have a “silent” season, imperceptible until the moment they are fertile, but most often the preliminary stages of the heat cycle provide plenty of warning to cue necessary segregation. If you maintain an intact dog, you must take all precautions to ensure an unwanted pregnancy does not occur, and you must be prepared to deal with the consequences if it does, which can be expensive and is a LOT of work - whelping and raising a litter, finding good homes for the puppies, vet visits for microchips and vaccines, etc.
• Ovariohysterectomy and castration are not the only solution to ensuring your dog is unable to reproduce. Alternative de-sexing procedures allow dogs to retain their sex organs such as vasectomies and tubal ligations. Unfortunately, it can be difficult to find vets trained in such procedures and willing to perform them.
Spaying and Neutering health benefits
Intact dogs have a .1% risk of developing testicular cancer and neutering eliminates that risk. When it occurs, testicular cancer is generally curable and has a very low rate of metastases.(4)
Neutered dogs may have a decreased risk of some prostatic diseases.
The risk of an intact female developing a mammary tumor is 0.5% if spayed before her first heat cycle (approximately 6 months of age), 8% after their first heat, and 26% after their second heat.(5) The average age of onset is 10, half of all cases are benign,(6) and very few cases are fatal.(7) Dogs overweight at 1 year of age are also at increased risk of developing mammary tumors.(8)
Intact females have a 23% chance of experiencing a dangerous uterine infection, pyometra, during their lifetime, and spaying eliminates that risk.
Both spayed females and neutered dogs are at a decreased risk for developing perianal fistula. These are uncommon in Flat-coated Retrievers . . . I don’t know of a single case.
Spaying and Neutering health risks
Hemangiosarcoma is a deadly cancer. It occurs in Flat-coated Retrievers at unfortunate rates. Neutered dogs have a 1.6% greater risk for developing cardiac hemangiosarcoma and spayed females are at a 5% greater risk. Spayed females are also at a 2.2% increased risk for developing splenic
Osteosarcoma is another Flat-coat cancer with a high mortality rate. Dogs neutered under one year of age are 4 times more likely to develop osteosarcoma and spayed females are 3 times more likely.(10)
Lymphosarcoma is another Flat-coat cancer. A 2013 study of Golden Retrievers, a close genetic relative of Flat-coats, revealed males neutered under a year of age to suffer a three-fold increase in developing lymphosarcomas.(11)
The Golden Retriever study also showed spayed females to be at an increased risk for developing mast cell tumors. While the intact control group experienced no occurrences of mast cell tumors, females spayed prior to one year of age experienced a 2.3% incidence, and females spayed after one year experienced a 5.7% incidence.(12)
Neutered dogs have a 2.84% increased risk for developing prostate cancers. Neutered males had a 3.56% increased risk for urinary bladder transitional cell carcinoma (TCC), and 8% (5.60-11.42) for prostate TCC, a 2.12% increased risk for prostate adenocarcinoma, and a 3.86% risk for prostate carcinoma.(13)
Neutered males have twice the rate of hip dysplasia as their intact counterparts.(14) Spayed and neutered dogs have are 3.1 times more likely to develop patellar luxation.(15) In the Golden Retriever survey, there was no occurrence of cranial cruciate ligament tears in either intact male or intact female dogs, or in late-neutered females. In dogs neutered or spayed before one year, the occurrence reached 5.1 percent in males and 7.7 percent in females.(16)
A study of Rottweilers showed females spayed after 6 years of age to have a 30% increase in lifespan than those spayed prior to 6 years.(17)
Spaying and neutering triples the risk of obesity.(18)
Spaying and neutering triples the risk of hypothyroidism.(19)
Up to 20% of spayed females experience urinary incontinence.(20) This is especially prevalent in early spayed females.