Neutering within the first year of life has long been standard practice in the United States and much of Europe. However, research has revealed that early neutering can raise the risks of joint disorders and cancers in certain breeds. A study published in July 2020 in Frontiers in Veterinary Science analyzed medical data for 35 breeds, expanding previous work on Golden Retrievers, Labrador Retrievers, and German Shepherd Dogs.
The disorders examined included hip dysplasia, cranial cruciate ligament rupture, and elbow dysplasia. Cancers tracked were lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. Findings showed that neutering before one year of age significantly increased the risk of these conditions in many large breeds, sometimes by a factor of two to four compared with intact dogs. Neutering by six months of age was linked to particularly high vulnerability in some cases.
In contrast, small breeds generally showed no increased risk of joint disorders related to neutering. Only two small breeds, the Boston Terrier and the Shih Tzu, demonstrated a significant rise in cancer risk. The results underscored profound differences across breeds, with some showing marked susceptibility while others exhibited little measurable effect.
To support owners and veterinarians, the study provided breed- and sex-specific guidelines on recommended neutering ages designed to reduce health risks. These guidelines emphasized that neutering decisions should not be generalized, but instead tailored to each dog’s breed characteristics and health context.
Source: Hart, B., (Geyer), L. A. H., Thigpen, A. P., & Willits, N. Frontiers in Veterinary Science, July 2020. https://doi.org/10.3389/fvets.2020.00388
