03/23/2026
We all want to prevent unwanted litters, but preventing litters does not have to mean removing hormones. There is a newer approach.
Veterinary reproduction specialists are increasingly recommending hormone preserving sterilization, a way to prevent unwanted litters while supporting long term health. Procedures like vasectomies and o***y sparing spays (hysterectomies) can be performed safely as early as 8 weeks, allowing dogs to retain the natural hormones their bodies need. For female dogs, an o***y-sparing spay can prevent pyometra because the uterus is removed, so the infection has nowhere to develop.
The 2026 peer-reviewed study published in the journal Animals by Isabel Pires and Rita Files on urinary bladder cancer in dogs and cats highlights that spaying and neutering (gonadectomy) are associated with an increased risk of urothelial carcinoma (UC), particularly in dogs, though the evidence is observational rather than causal. One cited epidemiological study found that neutered dogs had approximately 4.6 times higher odds (OR ≈ 4.57) of developing UC compared to intact dogs, suggesting a strong statistical association. The proposed biological mechanism centers on hormonal changes after sterilization: removal of the go**ds eliminates s*x hormone feedback, causing luteinizing hormone (LH) levels to rise dramatically (up to ~30× normal), which may stimulate cell proliferation in tissues like the bladder and potentially contribute to carcinogenesis. Additionally, neutering is linked to metabolic changes such as increased appetite, reduced metabolic rate, and a higher likelihood of obesity—another independent risk factor for cancer due to chronic inflammation and altered adipokine signaling.
