I just dealt with the same issues with my boys. I recomend rebond them a month or more after there desexed in a neutral place. just make sure u keep an eye on them. we sat with them for the first couple hours. holding them side by side periodically while petting them and feed them treats. They...
mine too, it really helped them in every way. Before i got them fixed they would bite and pee everywhere, even thought they were litter trained. Now there not aggressive and love to be cuddled, and they'll use there litter box, even if I move it.