In clinical practice, contraception in female dogs is traditionally achieved by surgical gonadectomy. As this method is discouraged by new animal welfare legislation in some parts of the world and is also related to several side effects, alternative possibilities for contraception are needed. Here, we report the distribution of aromatase in the canine ovary during different stages of the oestrous cycle. In-depth knowledge of oestrogen synthesis in the female dog is mandatory for targeted inhibition of oestradiol, possibly by the use of aromatase inhibitors. Photograph by M. P. Kowalewski.

Sperm analysis will evolve through the ‘omics’, telemedicine, advanced flow cytometry, and the artificial intelligence.Image by Biorender.com.

This article belongs to the Collection Dedication to Jim Cummins.