Veterinarians are discussing this issue in their professional journals and some dog owners are wondering what is best for their dogs whom they do not intend to breed.
Health issues involving skeletal structure and integrity and endocrine disorders can result as a consequence of early neutering, (spaying/castrating). I have long advocated for dogs not to be neutered until they are relatively mature and females after their first heat.
Giant breeds such as Great Danes and Irish Wolfhounds may be more prone to bone cancer after neutering and all dogs may be more susceptible to hip dysplasia and torn knee, cruciate ligaments, often associated with reduced activity as well as obesity and all the health consequences associated with same.
But neutering eliminates the possibility of testicular cancer, prostate issues and related perineal hernias as well as ovarian cancer and pyometra (infection of the uterus) in bitches. It may also reduce the incidence of mammary cancer.
Many veterinarians are now offering partial spay surgery, retaining dog’s ovaries but removing the entire uterus down to the cervical stump for health reasons under advisement that these dogs will cycle sill into heat and may have false pregnancies as well as attract male dogs.
Un-neutered male dogs may need special handling and vigilance around other dogs whom they may challenge and seek to mount, especially some neutered male dogs who may protest but be giving off pheromones that confuse intact male dogs. This can also happen when a dog has an undescended testicle that develops a Sertoli cell tumor producing female sex hormones.
On occasion, male dogs may become more aggressive after neutering which is indicative of the kind of hormonal stimulation from the brain (hypothalamus) reacting to the sudden absence of the hormonal feedback of testosterone from the gonads. Some veterinarians are now advocating post-neutering hormone-replacement therapy as a preventive measure and also to treat dogs with behavioral and health problems such as incontinence, anxiety, cognitive decline, hypothyroidism and various cancers ( notably bladder cancer, hemangiosarcoma, lymphosarcoma and mast cell tumors). For an excellent documented review of the pros and cons of canine sterilization see Dr. Sara Fox Chapman’s review article in the journal Integrative Veterinary Care, fall 2021, p 32-37.
Animal shelters have established early neutering as a protocol and prerequisite for adoptions, mainly because of the concern that irresponsible owners would allow their dogs to breed. over-population has been a major reason why so many dogs and puppies finish up in shelters across the country as well as abroad and having to be euthanized for lack of adoptees. Now this protocol needs to be re-examined especially in communities where dogs are now being brought in from other states and countries because animal shelters have too few local dogs and puppies available for adoption, the public demand escalating during the stay-at-home conditions created by the COVID-19 pandemic.
Informed veterinarians, considering their clients’ needs, age and lifestyles, and the kinds of breeds and sizes of dogs and puppies they are seeing, can best advise on this issue of spay/neuter. No single protocol fits all.