Introduction
The guinea pig (Cavia porcellus), also called the cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not in the pig family, nor are they from Guinea. They originated in the Andes, and studies based on biochemistry and hybridization suggest they are domesticated descendants of a closely related species of cavy such as Cavia aperea, C. fulgida, or C. tschudii, and therefore do not exist naturally in the wild. The guinea pig plays an important role in the folk culture of many Indigenous South American groups, especially as a food source, but also in folk medicine and in community religious ceremonies. Since the 1960s, efforts have been made to increase consumption of the animal outside South America.
In Western societies, the guinea pig has enjoyed widespread popularity as a household pet since its introduction by European traders in the 16th century. Their docile nature, their responsiveness to handling and feeding, and the relative ease of caring for them, continue to make the guinea pig a popular pet. Organizations devoted to competitive breeding of guinea pigs have been formed worldwide, and many specialized breeds of guinea pig, with varying coat colors and compositions, are cultivated by breeders.
Biological experimentation on guinea pigs has been carried out since the 17th century. The animals were frequently used as a model organism in the 19th and 20th centuries, resulting in the epithet "guinea pig" for a test subject, but have since been largely replaced by other rodents such as mice and rats. They are still used in research, primarily as models for human medical conditions such as juvenile diabetes, tuberculosis, scurvy, and pregnancy complications. Wikipedia
Common Breeds
Short haired
The short coated cavy - often called the American or English - has consistently short, glossy hair without a part. This breed of cavy most resembles the guinea pig's relatives and ancestors in the Cavia genus. In shows, short-haired guinea pigs are shown by their color variety - self, dalmatian, Himalayan, etc. This designation does not have 'American' or 'English' appended to it, but applies only to short-haired animals.
Abyssinian
The Abyssinian breed of Guinea pig is known for its short and long, rough coat that has cowlicked rosettes of hair. The derivation of the breed's name is unknown, but does not connotate an origin in the geographical region of Abyssinia (present day Ethiopia). The ideal Abyssinian has 10 rosettes, one on each shoulder, four across the back, one on each of the animal's hips, and two on the rump. Some judging bodies, such as the ANCC, consider shoulder rosettes optional but desired in show cavies. A harsh-textured coat that stands on end to form ridges is desired.
Peruvian
The Peruvian is the progenitor of all modern long haired breeds, being a guinea pig with hair that grows long continuously all over its body, sometimes to an excess of 20 inches. Accordingly, this ornate feature can make caring for this breed more difficult for both owners and breeders; most show Peruvians have their hair folded up in wraps to protect it and keep it clean. Long haired Guinea pigs have both a top and an undercoat, the latter of which will generally only grow to 6-7 inches. Most Peruvians kept as pets are regularly trimmed for ease of keeping.
Teddy
A Teddy guinea pig has a very dense and fuzzy coat, with hairs that stand up. The fur typically grows to a moderate length and generally makes this breed resemble a soft toy more than any other. Another unique feature of the Teddies is the relatively long hair coating their bellies, in contrast to other breeds, whose bellies are nearly bare. There are two kinds of Teddy: The US Teddy and the CH Teddy, otherwise known as the Swiss Teddy. The two variations appear to be both genetically and visually different.