Small pets do not generally require neutering if kept in a single-sex cage. I keep rats, mice, and other rodents as a hobby, and have never needed to have any of them fixed. I just keep them in cages segregated by sex, and since they’re not outdoor pets that can find mates on their own by roaming, no unwanted litters result. However, there are health reasons that some people may get their female rats spayed for, and behavioral reasons for males. Female rats are very susceptible to mammary tumors, and their chances of suffering this, along with reproductive infections and cancers, are greatly decreased if they are spayed. For male rats, it is less an issue of health and more of temperament; if a male rat is too aggressive, then neutering may help mellow him out. It is not guaranteed, and can come with a slight increased for obesity, but studies show that neutered male rats display 85% LESS aggressive behavior, and they are also 50% less likely to be attacked by an un-neutered male rat. So if your two males are having problems with each other, fixing one or both may help. It is also a MUST if you want to keep a male with females! Note that if you do choose to fix your pet rat, be sure to only take them to an experienced exotics veterinarian, and NOT one that only works on cats and dogs. In short, there are some benefits for fixing rats, but it’s not necessary in most cases. Male mice (mice are different than rats!) may be neutered if you want them to be able to live with females or other males (unlike rats, which need friends, male mice must NOT be kept together normally!) but this should only be done if you have to, as it is a risky procedure for them (they are smaller and more delicate than rats are). Spaying a female mouse is even riskier, and it should only ever be done if the mouse is having medical problems related to her reproductive organs. Ultimately, fixing for rats is strictly elective, while for mice it should be avoided if possible. Fixing is also not a requirement for hamsters; I’ve never owned an altered hamster. Guinea pigs of both sexes reap many health benefits from spaying and neutering, but, as with other small pets, you should only ever have this done by a veterinarian with experience working on guinea pigs.
Altered rabbits live longer and are better behaved than not, as well as healthier, for many of the same reasons as cats and dogs. Altered rabbits can also have a rabbit friend to play with; un-altered rabbits cannot, they are too aggressive with other rabbits regardless of the sex of their companion.
There is a good deal of controversy among chinchilla owners regarding whether they should be neutered/spayed, owing to debate over whether the anesthesia and the procedure itself is safe for them. Like mice, chinchillas are very delicate animals, despite being larger than rats. The main reason for fixing chinchillas is to prevent unwanted litters when opposite-sex animals are housed together. It is more common to neuter males than females, since the operation is easier. If you do choose to fix your chinchilla, see only an experienced exotics vet and do extensive research on the after-care procedures. This should apply to ALL small pets, but especially chinchillas due to their fragile constitutions.
Female ferrets MUST be spayed! If a female ferret goes into heat and does not mate with a male, she can in fact die! It is estimated that 90% of female ferrets will die during their first heat if this happens to them. If you aren’t planning to breed your female ferret, get her fixed ASAP! As for male ferrets, fixing them will decrease aggression, and alteration will decrease odor in both sexes.
Next time---reptiles and birds!