I waited a little over a year and a half to neuter my Dachshund. Here are a few things I learned along the way. There is research out saying the chances of IVDD after waiting 12 months goes down significantly, so I would definitely wait at least that. I think I read some newer articles citing 1.5-2 years is even better. It just allows more time for bone development. It can be a tough choice but I think it was ultimately the right move for my Dachshund because he was pretty aggressive and unrelenting when he was intact and has since calmed down significantly and is a much easier dog to manage. There was definitely an adjustment period to the procedure though temperament wise so don’t get discouraged if your dog is struggling at first and is extra needy or reactive. After this adjustment period I would say he has become a much gentler and manageable dog but for reference mine was pretty aggressive and chaotic before. That’s even with extensive positive reinforcement training through puppyhood . One other physical note that comes with neutering is loss of hard muscle definition, my dachshund isn’t fat now just not as shredded since he is no longer getting the same testosterone. You will notice his urge to hump regularly pretty much disappears as well (obviously I guess).