thats going to vary by vets.
the main important question is do you really need it done. i know it has been done succesfully, but it is a very dangerous proceedure. its one thing if a chin's life depends on it, but just to do it, personally i wouldn't take the chance.
i have spoken with many rep breeders about it because i was going to do it, and they told me about all the dangers.
good luck with whatever decision you make.
It's only dangerous if you've got an inexperienced vet. I'm not sure why so many breeders still trot out how dangerous it is, but there are many, many rescues successfully neutering chinchillas in great number. According to our vet (and to chins and quills), neutering a chinchilla is nearly identical to neutering a guinea pig (which some breeders also espouse as super dangerous).
We've neutered all of our male chins and most of our male guinea pigs in our rescue for several years now, and have had zero complications, much less dangerous problems.
If your vet can't successfully neuter a chin, which is one of the easiest surgeries you could ever do on such an animal -- doesn't that make you wonder what would happen if they needed more serious surgery?
Since our first neutering, which ended badly because the chin happened to have a rare allergic response to anesthesia, we've had two exotics specialist vets successfully neuter over two dozen of our boys as of 2008. We know others (from our rescue work in the U.S.) who've had a dozen or more neuterings done and Humane Societies also frequently neuter chins before rehoming them. In other countries where neutering is routine, one rescue we correspond with has had literally HUNDREDS of neuterings!
This just goes to say that as with anesthetizing, it IS possible to do this (neutering) safely. ANY surgical procedure performed on chins should not be taken lightly, take time to read the neutering articles above as well as ALL the information below. For this section we've consulted at length with our two neutering-experienced exotics specialist vets as well as attended and observed, photographed and documented, several neutering surgeries.
The most typical complication is post-surgical abscessing, but if you're monitoring carefully, keeping them confined to a hospital cage, and weighing religiously, they're easy to catch before they reach anywhere near a level which could be considered dangerous.