There are many breeds of Guinea pig
which have been developed since its domestication
ca. 5000 BC. Breeds vary widely in appearance and purpose, ranging from show breeds with long, flowing hair to those in use as model organisms
by science. From ca. 1200 AD to the Spanish conquest of the Inca Empire
, selective breeding by indigenous South American peoples resulted in many varieties of domestic guinea pigs, which form the basis for some of the modern domestic breeds. Early Andean breeds were primarily kept as agricultural stock for food, and efforts at improving the Guinea pig as a food source continue to the modern era.
With the export of Guinea pigs to Europe in the 15th century, the goal in breeding shifted to focus on the development of appealing pets. To this end, various competitive breeding organizations were founded by fanciers. The American Cavy Breeders Association, an adjunct to the American Rabbit Breeders Association, is the governing body in the United States and Canada. The British Cavy Council governs cavy clubs in the United Kingdom. Similar organizations exist in Australia (Australian National Cavy Council) and New Zealand (New Zealand Cavy Club). Each club publishes its own Standard of Perfection and determines which breeds are eligible for showing. New breeds continue to emerge in the 21st century.
Though there many breeds of Guinea pig, only a few breeds are commonly found off the show table as pets. Most Guinea pigs found as pets were either found undesirable by breeders or were bred to be good companions regardless of how well they meet the breed standard of perfection. The short hair, Abyssinian, Peruvian and Sheltie (aka Silkie) breeds are those most frequently seen as pets, and the former three are the core breeds in the history of the competitive showing of Guinea pigs. In addition to their standard form, nearly all breeds come in a Satin variant. Satins, due to their hollow hair shafts, possess coats of a special gloss and shine. However, there is growing evidence that the genes responsible for the Satin coat also can cause severe bone problems, including Osteodystrophy and Paget's disease.
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
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.
The Abyssinian breed of Guinea pig is known for its short, 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.
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 (approx. 50 centimeters). 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 (15-17 cm.)Though most Peruvians kept as pets are regularly trimmed for ease of keeping, those in show coat should have hair that fans out to make the animal's front and rear completely indistinguishable. The coat should be of an even length all over, and have a central part on the spine. Peruvians of show standard are required to have two rosettes on either side of the rump, which creates the desired height and density.
Silkie or Sheltie
A Silkie has long hair that flows back over its body and never forward over the face (as in the Peruvian). When viewed from above it forms a teardrop shape and should never have a central part. In contrast to the Peruvian, where the coat is desired to fall in an even curtain all around the body, the Sheltie is generally accepted to have a somewhat longer sweep of hair in the rear.
A Rex guinea pig has short, fuzzy hair that stands on end all over the body. The hair should be uniform all over, without rosettes and no more than 1⁄2 inch (1 1⁄4 cm) in length, preferably shorter. The Rex breed sometimes looks similar to the Teddy, but the two breeds are genetically distinct--breeding a Rex to a Teddy will not result in Rex or Teddies, but rather American cavies.
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. Young Teddies sometimes look similar to the Rex, but the Rex's fur is shorter and usually much more bristled. 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.
A Texel Guinea pig is like a Silkie, but with curls. Originating from England, it was officially recognized as a breed by the ACBA in 1998. The curls should ideally be tightly wound corkscrew curls and should cover the entire body, including the stomach. Unlike a Sheltie, a central part is allowed.
Relatively rare or emerging breeds
A curly coated Peruvian. Hair grows over face like a Peruvian. Most are first generation hybrids of Peruvians and other breeds.
The Crested is similar to the American, but has one rosette on the top of the head. According to ACBA standards, the Crest must be white, with no other white hair present on the animal.
The ANCC (Australian National Cavy Club) recognizes 2 main groups of crested. The American Crested and the English Crested.
The American Crested must have a crest colour that is in contrast to the body colour. Usually this is white, but it could be any other colour. These are only recognized in the self colour. English Cresteds have a crest the same colour as the body. These are recognized in every colour and variety, with the exclusion of the "coated" breeds (longhairs and coarse coats). The most popular being breeds such as the English Crested Pink Eyed White and the English Crested Black.
A Coronet cavy has longer hair, like the Silkie, along with a crest like a Crested.
A curly-coated Coronet with a crest in between the ears on the centre of the head.
A long-haired breed originating in Scandinavia.
A very few varieties of hairless Guinea pig exist, the most prevalent breed being the Skinny pig
. Skinnies were developed from a hairless lab strain crossed with Teddies and other haired breeds. They have curly Teddy hair on their noses, feet and legs. Skinnies are born nearly hairless. Another well-known hairless guinea pig is the Baldwin. The Baldwin was a spontaneous mutation from White Crested cavies belonging to a cavy fancier who was breeding them for show. Baldwins are born with a full coat which falls out until they are bald. The Baldwin is characterized by numerous skin wrinkles and a very small amount of hair just on the feet only. The Skinny and the Baldwin are two separate breeds and the two different hairless genes are not compatible. Hairless breeds require special accommodation, as they need to be kept warm and may require extra food. Currently a few Scandinavian bodies admits hairless breeds on to the show table, and consequently a standard of perfection exist.
Like the Skinny pig and Baldwin, the Ridgeback is not recognized by any international show organization. Genetically, it is similar to an Abyssinian, however, it has few rosettes, and appears to be smooth coated other than a ridge of hair running up the back.
Abbyruvian is not a recognized breed, but a nickname for Abyssinian cavies that are partially long-haired. Genetically, these animals have one copy of the long-hair allele and one copy of the short-hair allele. Physically, they look like a cross between an Abyssinian and a Peruvian. They generally have short hair on the head, belly, limbs, and rear, and a patch of long hair on the back. The hair typically curls back in such a fashion as to be called a "rooster tail". The same mix of long and short hairs can occur on a smooth-coated cavy, but there is no nickname for it. The long hairs are, however, known as "skirts".
Cavies come in many colours, but only three different colors can appear on each cavy, one from the black series, one from the red series, and/or white. The black series includes black, chocolate, lilac, and beige. The red series includes red, orange, buff, cream, and white.
- Agouti coloured cavies have a hair tip and root that are different colours, much like someone whose roots are showing from dyeing their hair. The root contains whatever color from the black series the pig has, and the tip has whichever color from the red series the pig has. Agouti guinea pigs have bellies the same color as the tips of their hair.
- Golden Agouti has a red tip and black root.
- Silver Agouti has a white tip and black (or grayish) root.
- There are also many dilute agouti variations with different combinations of the black series and red series.
- "Solid" coloured cavies are much like Agoutis, but the belly is ticked as well. Solid and Agouti cavies can have patches of solid red series, but all black series hairs wind up ticked.
- "Self" cavies have just one color of hair--black, white, cream, etc.
- Broken colour cavies have two or three colours of hair in any combination not otherwise recognized.
- Tortoiseshell cavies have patches of red and black. For show breeders, the ideal is to have an evenly checkered animal with clear, straight dividing lines between the two colors.
- Tortoiseshell and white cavies have even patches of red, black, and white.
- Brindle cavies have black series and red series hairs evenly mixed throughout their coats. However, these hairs are not ticked.
- Magpie is a particular form of brindle with black for the black series and white for the red series. Magpie can be easily confused with roan, although in magpie the white hairs can appear anywhere, while roan cavies rarely have any white on their head or rear.
- Dutch cavies have bands of color, generally on the cheek area and the rear, with bands of white in-between. The pattern is essentially the same as the Dutch pattern in rabbits.
- Roan and Dalmatian cavies are genetically the same, but look somewhat different. Roans have white hairs evenly mixed throughout their other hairs on back and sides, while Dalmatians have spots of color on a white back and sides. Many are intermediate between the two patterns, with some spots and some mixed-in hairs. The white hairs caused by roan and dalmatian patterns are genetically different from normal white, or the white in the red series, or the white of the Himalayan pattern. Therefore, an animal could have white roan hairs mixed in with white hairs from ordinary white spotting, covering up the telltale roan markings. This is a problem because two guinea pigs who are both roan and/or dalmatian could produce deformed offspring. Hence, no guinea pig with an unknown genetic background and any white hair should be bred.
- Himalayan cavies are acromelanic, just like the Siamese cat. Their noses, ears, and feet are a black series color. If a cavy with Himalayan genes has a genotype that would give them red series, or white, on their nose, ears, or feet, those hairs will be white. This could result in an entirely white animal, or one that is white with black ears, or a half-black nose. Himalayan guinea pigs are always born pure white from the heat of the mother's body, and any colored hairs develop slowly.