An update on the risks and benefits of neutering in dogs

Abstract

Surgical neutering of pet dogs has generally been regarded as an important means of population control that also has both health-related and behavioural benefits. Perceived health-related benefits include prevention of mammary tumours and pyometra in bitches and testicular and prostatic disease in male dogs. Perceived behavioural benefits are associated with a reduction in sexually-dimorphic behaviours including roaming, mounting and urine marking in male dogs, and problem behaviours associated with seasons or phantom pregnancies in bitches. In recent years a number of research studies have suggested that the health-related benefits of neutering may be less marked than was once believed, and that neutering may also have negative health-related effects, particularly associated with the development of joint disease and neoplasia. While this is concerning, there are factors that may influence the validity of the results of these studies and the degree to which they can be reliably extended to all dogs. This also applies to the studies that have looked at the effect of neutering on behaviour in dogs. In the absence of clear information particularly regarding the health-related effects of neutering it is currently very difficult to give neutering guidelines that will be suitable for all dogs, and that will reliably reduce the risks of them developing specific diseases. This may change as more research becomes available. Until then, it is better to work out the risks and benefits of neutering for each individual dog based on the risk of unwanted mating occurring and the presence or absence of problem behaviours influenced by sex hormones, in addition to the owner's preference.