Publication
Gretel Torres de la Riva, Benjamin L. Hart, Thomas B. Farver, Anita M. Oberbauer, Locksley L. McV Messam, Neil Willits and Lynette A. Hart (2013). Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers. PLoS ONE 8(2): e55937.
Original source (DOI) · Download article (PDF) [2]
DTW summary
- In this retrospective study of 759 Golden Retrievers aged 1–8 years, neutering before 12 months was associated with more hip dysplasia and lymphosarcoma in males, and more cranial cruciate ligament tears in both sexes, compared with remaining intact.[2]
- Females neutered at 12 months or older had more hemangiosarcoma than intact or early-neutered females, and more mast cell tumors than early-neutered females.[2]
- These hospital-record findings are associations, and the authors caution against extrapolating them to other breeds or dogs in general.[2]
Abstract
In contrast to European countries, the overwhelming majority of dogs in the U.S. are neutered (including spaying), usually done before one year of age. Given the importance of gonadal hormones in growth and development, this cultural contrast invites an analysis of the multiple organ systems that may be adversely affected by neutering. Using a single breed-specific dataset, the objective was to examine the variables of gender and age at the time of neutering versus leaving dogs gonadally intact, on all diseases occurring with sufficient frequency for statistical analyses. Given its popularity and vulnerability to various cancers and joint disorders, the Golden Retriever was chosen for this study. Veterinary hospital records of 759 client-owned, intact and neutered female and male dogs, 1–8 years old, were examined for diagnoses of hip dysplasia (HD), cranial cruciate ligament tear (CCL), lymphosarcoma (LSA), hemangiosarcoma (HSA), and mast cell tumor (MCT). Patients were classified as intact, or neutered early (<12 mo) or late (≥12 mo). Statistical analyses involved survival analyses and incidence rate comparisons. Outcomes at the 5 percent level of significance are reported. Of early-neutered males, 10 percent were diagnosed with HD, double the occurrence in intact males. There were no cases of CCL diagnosed in intact males or females, but in early-neutered males and females the occurrences were 5 percent and 8 percent, respectively. Almost 10 percent of early-neutered males were diagnosed with LSA, 3 times more than intact males. The percentage of HSA cases in late-neutered females (about 8 percent) was 4 times more than intact and early-neutered females. There were no cases of MCT in intact females, but the occurrence was nearly 6 percent in late-neutered females. The results have health implications for Golden Retriever companion and service dogs, and for oncologists using dogs as models of cancers that occur in humans.
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