And that’s if you can find someone confident enough to do it. Small size (so they can start hitting hypothermia in like 5 minutes-), unique mouth and jaw anatomy (so getting a tube in them is like picking a lock) and increased sensitivity to the respiratory effects of anesthesia (so suddenly just no longer breathing is a real possibility).
Basically one you hit rabbit size or below things get more complicated.
You could do it without anesthesia like how it’s done for piglets in farms but that would possibly be illegal. I think it’s technically illegal to neuter piglets that way. But I don’t know, pets and farm animals have different rights legally.
Not sure on legality, but it’s usually logistics with farm animals. I mean just imagine rounding up 50 pigs, giving each a local anesthetic and restraining to do a surgery that’s gonna take maybe half an hour at maximum. And to top it off, unlike a dog, pigs don’t really have a lot of FDA-approved options for pain relief. But if you don’t castrate, once they hit puberty they’ll start smelling like shit stink and sweaty gym socks, and selling meat with literal shit stink compounds in it is illegal (if anyone would even want it-). Usually a matter of ‘least harm that’s feasibly possible’ rather than ‘no harm’. Improvsest has promise, though, so if they can iron out the wrinkles in it then the physical castration might be a thing of the past.
Come to think of it the FDA probably hasn’t approved much of anything for Fluffies.
I was talking about the hamster case. Would be quite cruel tho. But then again, so is when they restraint pigs and slice their ballsack open and then neuter them with no sedation.