Early Spaying Linked to Incontinence in Shelties

It’s a question that a lot of pet owners face—at what age should dogs be spayed or neutered? Can spaying or neutering too early cause health problems? If you’re in the process of making this important decision for your pet, new research by UC Davis School of Veterinary Medicine could provide some clarity.

The research team analyzed hospital records of 35 dog breeds, including Shetland sheepdogs, to see if there is a correlation between age at sterilization and the risk of developing joint disorders, cancer, and urinary incontinence. Their goal was to “increase the information available to pet owners and veterinarians when making decisions regarding spaying and neutering.”

In all, 133 Shelties were studied, consisting of 31 intact males, 30 neutered males, 20 intact females, and 52 spayed females. There was no evident link between spaying/neutering and joint disorders or cancer, regardless of the age when the spaying or neutering occurred. However, in female Shelties, researchers did find a correlation between spaying and urinary incontinence, with a 33% occurrence in those spayed at one year. To reduce the risk of UI, they advise caregivers to consider spaying at two years or older.

Importantly, the study authors conclude by noting that “decisions on whether and when to neuter a specific dog are complicated and reflect a consideration of the dog's breed, health status, and living situation, as well as available information pertaining to risks for these joint disorders and cancers. These varied results highlight the complex effects of neutering and the age at which it is conducted. They point to the importance of personalized decision-making.”

For more information, please see:

New Study Updates Spay-Neuter Timeline Guidance for Popular Dog Breeds. The American Kennel Club. (2025). Available at https://www.akc.org/expert-advice/news/study-updates-spay-neuter-guidelines/

Hart BL, Hart LA, Thigpen AP, Willits NH. Assisting decision making on age of neutering for 35 breeds of dogs: associated joint disorders, cancers and urinary incontinence. Front Vet Sci. (2020) 7:388. doi: 10.3389/fvets.2020.00388