From the GLX-Files
Skinnies are a breed of guinea pig that have very little hair on their bodies. They have specific care requirements and can suffer from genetic problems.
Skinny Pigs (and Baldwins) have Teddy genes. Baldwins are the show breed and Skinny Pigs were originally laboratory stock. Baldwins are usually completely hairless as adults, although they may be born with some varying degrees of Teddy fuzz. Skinny Pigs usually retain Teddy fuzz around their face and sometimes feet and are usually born without much hair.
The two breed genes are different and not compatible. Both breeds have a host of medical problems and should only be considered by a pet owner experienced with guinea pigs and prepared to deal with their medical conditions. Skinnies have all the Teddy health problems and are prone to serious heart disease and skin disorders such as melanoma and fungal infections. They are the highest maintenance cavy breed. Skinnies require a higher caloric intake, probably due to the fact they do not have any coats to insulate or regulate their own body temperatures.
Skinnies are more prone to skin cancers Skinny Pig Melanoma and heart disease.
Skinnies have a higher metabolism and require more food and a warmer environment. Their cages require more frequent cleaning. They may require special treatments for fungal skin infections.