I did hear that undescended testicle is a hereditary condition and that males with that condition shouldn't be bred.
Cocoster had that surgery when he was 13 months old (now he's 18 months old) and a lil over 5 pounds. The recovery definitely takes longer than a regular neuter. It took Cocoster about a week to move around normally. He was on pain meds for 3 days. His incision shocked me when I first saw it because it was longer than I expected.
It seemed like the longest week ever. I didn't feed him anything the first day, but I made sure he drank and ate a little after that. I took time off from work to stay with him during the day so I can watch him, and I made him wear an onesie overnight so he wouldn't lick his incisions.
Sometimes the vet can feel where the undescended testicle is, which makes it an easier surgery.
My vet had to "dig" for Cocoster's because it couldn't be felt from the outside.
