Best age to castrate

[Nanno]

I castrate my boys at 12-16 weeks. I do it on the 12 weeks side if they're robust and getting randy. I do it on the 16 weeks side (and sometimes even a little later) if they're smaller than average and aren't interested in girls. The only study I know on the issue showed that the urethra does almost all of its growing in the first 12 weeks. Growth after that is pretty negligible. I can try to dig that study up if you like.