Does early neutering increase the risk of cranial cruciate ligament rupture?

Abstract

PICO Question In bitches, does gonadectomy before 1 year of age compared to gonadectomy at 1 year of age or older, increase the risk of cranial cruciate ligament disease during their life? Clinical bottom line Category of research Risk. Number and type of study designs reviewed Eight studies were reviewed, four of which were retrospective cohort studies, two of which were prospective longitudinal cohort studies, one of which was a retrospective case-control study and one of which was a prospective case-control study. Strength of evidence Moderate. Outcomes reported The evidence was mixed, but overall was suggestive that gonadectomy before 1 year of age increased the risk of cranial cruciate ligament disease in bitches. Gonadectomy before 1 year of age was found to increase the risk of cranial cruciate ligament disease in seven of eight studies. Most studies assessed a narrow range of breeds and the generalisability of these results to all dogs is thus limited. The one study which assessed a range of 35 breeds noted an increase in risk of cranial cruciate ligament disease in 6 of 35 breeds associated with gonadectomy before 1 year of age. Direct comparison of studies is limited by the varying age stratifications, breed analyses, and study methodologies. Conclusion Gonadectomy before 1 year of age in Golden Retriever, German Shepherd, and Rottweiler bitches may increase the risk of cranial cruciate ligament disease. In other breeds, limited evidence is available to draw conclusions. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.