Peruvians are a challenging breed, as they require many hours in grooming and handling. First you select a good baby, and watch them grow. Then, when their coats are long enough (just touching the ground for most) you begin to wrap their coats, or sweeps as they are known as.
You select a baby based on good body condition, good type, and good health, but the primary concern is that you must also look for coat quality. A baby Peruvian should have a very silky coat. The coat should also have good density, which can be felt by stroking the coat against the direction of hair growth. A good indication is an animal that has a wave to the coat. A cavy with a coarse coat will feel denser than it is.
Grooming, handling and desensitation starts at an early age. You should handle the animal when it is young and brush it periodically even if the coat is not long enough to need it. This gets the animal used to handling and brushing. When the coat is about three inches long, it is time to start wrapping it. In order to wrap the coat, you take a piece of paper towel or fabric, fold the towel in half, then in half again. You place the towel under the combed sweep (generally you don't want more than 2" of sweep per wrap) and fold it up over both sides, forming a tri-fold. You then fold the paper up to form a package about I inch square, You fasten the package with a rubber band. When the cavy is adjusted to its rear wrapper, you repeat the same procedure on each side. Do not try to put a wrapper in the head furnishings. The cavy will try and very often succeed in getting out of his wrappers. The main problem here is that you don't want the wraps too tight, as this can hurt, and to alleviate the hurt, they WILL chew the wraps off. If too loose, they'll lose the wrap in the cage, causing a matt. These wraps need to be changed every other day and combed out.
At least one week before you show an animal, it should be bathed. This can be done in a sink using warm water and animal shampoo or baby shampoo. The cavy is thoroughly soaped and then rinsed completely free of any remaining suds. When washing, it is important, to make sure that you do not get the hair tangled in the cavy's feet. It is important to make sure that the cavy is completely dry before you try to brush or re-wrap the coat.
Many Peruvians become nervous with wraps and chew their coats. Two aids to prevent chewing are hay and Calf Manna or sweet feed. Hay adds roughage to the diet and gives the Peruvian something to chew on when it is bored besides its coat. Since a Peruvian's coat is protein, a high protein supplement, such as Calf Manna gives the animal an extra source of this important nutrient.
(the bulk of this information comes from the 1974 ARBA handbook, an article on Care of the Peruvian cavy)