[Neutering of female dogs - old and new insights into Pros and Cons].

Advice for dog owners regarding the Pros and Cons and optimal time for neutering a female dog is complex and should be based on recent and valid research data as well as individual aspects. After taking a closer look at the literature, it becomes clear that some putative robust information has to be revised or updated. An obvious advantage of neutering a female dog is that ovarian diseases and sexual steroid-dependent diseases, including metropathy, no longer occur. In addition, it is likely that an early neutering reduces the risk to a certain extent of mammary neoplasia, even if the scientific basis for this observation is weak. The effect might be less than some earlier publications suggest. Disadvantages of neutering female dogs include urinary incontinence, which was postulated decades earlier. However, reported incidences and findings regarding factors that influence urinary incontinence, including time of neutering related to puberty, are heterogeneous. Recently, several studies have been published suggesting a significantly higher risk of different forms of neoplasia and musculoskeletal disorders in neutered dogs. However, factors that may bias these findings, including nutritional condition, age and/or housing, were not addressed in most studies. Data on effects on metabolism and the immune system are currently very limited. If owners want their female dogs to be neutered, a thorough counselling is essential that includes individual aspects as well as breed- and housing-specific factors. The optimal time may be between the first and the second heat. It can be suggested, that at this time, a certain reduction of the risk of mammary neoplasia can be achieved with only a moderate potential for undesired side effects.