The MSPCA adoption centers encounter their fair share of small animals, including guinea pigs, rats, mice, degus, chinchillas, ferrets, hamsters, and gerbils. Generally considered easy to care for, these little animals still require daily care and attention. Because they are popular first-time pets, many people acquire small animals without considering every factor in their care: daily cage cleaning, handling, exercise, and feeding for their entire lives, anywhere from 1-7 years depending on the species. And because these small prey animals are too frequently purchased as gifts for children, they simply aren't afforded the degree of care they deserve. Add to this the fact that a number of small animals come from pet stores improperly sexed (therefore risking unwanted pregnancies if paired with the opposite gender), or worse yet - are already pregnant when purchased from the pet store - and the result is litters of small animals without homes.
The most common reasons small animals are surrendered to the MSPCA are because the children in the house have lost interest, the family doesn't have time to care for them, or there are too many (accidental breeding).
Fortunately, the breeding of ferrets is very well managed, and only those with a license may breed them. All ferrets sold through pet stores or breeders, or adopted from shelters, are already sterilized. While some veterinarians will spay/neuter guinea pigs, it's a much less common surgery. The MSPCA recommends that guinea pigs only be cage mates if they are sterilized or of the same gender (and this should be verified by a vet or another knowledgable person to be safe!). Pairing females is often more successful than pairing males, though males have been known to pair more successfully the younger they are.
And while other small animals are less prone to some of the undesirable behaviors we sometimes see in rabbits (cage aggression, for example), most are still prey animals and naturally more skittish than other species. They require a fair amount of gentle and consistent handling to become comfortable with humans. It's important that parents teach their kids how to hold a small animal the proper way, and supervise interactions to make sure everyone is safe. It isn't fair for parents to give full pet care responsibilities to a young child. This is a quick way for a child to become bored with - or resentful of - their pet!
Before getting a small animal, learn about their behavior and care needs, and make an informed choice about whether it's the best pet choice for you.