There are actually two varieties of hairless guinea pigs. The Skinny Pig (which actually does have a bit of hair) and the Baldwin Guinea pig. There is some controversy about the introduction of these guinea pigs to the pet industry. They were originally bred for laboratory research and concerns about their immune system function and overall hardiness, have been raised. Others say that through careful breeding, it is possible to produce hairless guinea pigs that are hardier than their lab-bred ancestors. And while some people find their unique appearance unappealing, others find them quite irresistible.
Their care is much like that of other guinea pigs. However, lacking a coat they are a bit more sensitive to temperature extremes and must be protected from drafts as well as direct sunlight.
They also tend to eat more to maintain their metabolism and body heat (an excellent quality diet is a necessity, but should be provided to all guinea pigs, hairless or not).
The following pages feature some photos which show the differences between the Skinny pigs and the Baldwins.