I had my Border Collie done when he was about 5mnths old, his morning routine was to roll on the bed with me for a while and have his tummy rubbed before we got up and went outside to toilet. This one morning, about 3wks after he'd been done, he was rolling as usual and I happened to notice he looked swollen down there, on a closer look it seemed only his 'thingy' was swollen... my immediate reaction was that the vet hadn't done his job properly and I was all set to ring them after I'd got up. I let Ky out and then went and got dressed, let him back in and checked again... yep, swelling had gone down... imagine if I had of rang the vet saying he'd been fixed and yet had woken up with 'Morning Glory' when he actually was just bursting for a pee!