Hi Duncan,
Speaking from a racers point of view, I know of a non-ped whippet called Pickpocket that was spayed and this bitch was an open class flying machine, so I would say it doesn't affect their speed/prey drive
I opted for the same as you, and to be honest I wish I hadn't, heaving and farting at the same time, quite embarrassing
Mind you. it wasn't as bad as having a camera up the pipe of my dick, with 2 young nurses standing over me and giggling.
So sad, don't know what to say, life can be so cruel, it certainly puts things into perspective when something like this happens.
RIP mIchelle
Hope its good news for you Bryson