My cavy is interacting poorly with my rabbits and it seems to primarily be based around hormones.
The shelter that I rescued my guinea pig doesn't fix their guinea pigs because they claim they are "too small".
While this makes sense for me with respect to spaying, it seems to me that because neutering is so much less invasive the procedure should be rather trivial. Am I wrong? are there other reasons, aside from removing it's ability to breed that I would not want to neuter my cavy?
Several guinea pig references say the same thing, but Cavy Spirit is pretty well known
The only valid, non-medical reason to neuter your male guinea pig is because you have a female you want him to room with. Neutering does little to change the behavior of aggressive guinea pigs, unlike the effect it has on other types of animals. Likewise, neutering does little to curb mounting or sexual behavior. It will prevent unwanted pregnancies. There is no need or reason to neuter two boars living together. If they don't get along now, neutering won't help
Further down the page they go into some detail on what makes this surgery so difficult and risky, so it's something to keep in mind as well:
The testicles of dogs and cats are relatively prominent and outside of their body. The inguinal (groin) rings of guinea pigs are open and testicles can be retracted into the abdomen. If not done properly, the abdominal contents can prolapse through the suture sites, causing death.
