Guinea pig
62696
226110270
2008-07-16T21:29:57Z
Postdlf
29695
- redundant category; "pet rodents" is subcat of "animals kept as pets"
{{otheruses}}
{{Taxobox
| name = Domestic Guinea Pig
| status = DOM
| image = Guinea 1.jpg
| image_width = 300px
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Mammal]]ia
| ordo = [[Rodent]]ia
| subordo = [[Hystricomorpha]]
| familia = [[Caviidae]]
| subfamilia = [[Caviinae]]
| genus = ''[[Cavia]]''
| species = '''''C. porcellus'''''
| binomial = ''Cavia porcellus''
| binomial_authority = (Erxleben, 1777)
| synonyms = ''Mus porcellus''<br />''Cavia cobaya''<br />''[[Cavia anolaimae]]''<br />''Cavia cutleri''<br />''Cavia leucopyga''<br />''Cavia longipilis''
}}
The '''Guinea pig''' (also commonly called the ''cavy'' after its scientific name) is a species of [[rodent]] belonging to the family [[Caviidae]] and the genus ''[[Cavia]]''. Despite their common name, these animals are not [[pig]]s, nor do they come from [[Guinea (region)|Guinea]]. They are native to the [[Andes]], and while now extinct in the wild, they are closely related to several species that are commonly found in the grassy plains and plateaus of the region. The guinea pig plays an important role in the [[folk culture]] of many [[Indigenous peoples of the Americas|indigenous]] [[South America]]n groups, especially as a food source, but also in [[folk medicine]] and in community religious ceremonies.<ref name=morales>{{cite book | last = Morales | first = Edmundo | title = The Guinea Pig : Healing, Food, and Ritual in the Andes | publisher = University of Arizona Press | date = 1995 | isbn = 0-8165-1558-1 }}</ref> Since the 1960s, efforts have been made to increase consumption of the animal outside South America.<ref name=cbs>{{cite news | last = Vecchio | first = Rick | title = Peru Pushes Guinea Pigs as Food | publisher = [[CBS News]] | url = http://www.cbsnews.com/stories/2004/10/19/world/main650148.shtml | date = [[2004-10-19]] | accessdate = 2007-03-12|}}</ref>
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 [[Animal fancy|competitive breeding]] of guinea pigs have been formed worldwide, and many [[Domestic varieties of guinea pigs|specialized breeds]] of guinea pig, with varying coat colors and compositions, are cultivated by breeders.
''Guinea pig'' is also used as a [[metaphor]] in English for a subject of experimentation; this usage became common in the first half of the 20th century. 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, but have since been largely replaced by other rodents such as [[house mouse|mice]] and [[brown rat|rat]]s. They are still used in research, primarily as models for human medical conditions such as [[juvenile diabetes]], [[tuberculosis]], [[scurvy]], and [[preeclampsia|pregnancy complications]].
== History ==
[[Image:Guineapiglarcomuseum.jpg|left|thumb|Moche Guinea Pig ca. 200 A.D. [[Larco Museum]] Collection, Lima, Peru]] The common guinea pig was first [[domestication|domesticated]] as early as 5000 BC for food by tribes in the [[Andes|Andean]] region of [[South America]] (present-day [[Ecuador]], [[Peru]] and [[Bolivia]]).<ref>Morales, p. 3.</ref> [[Statue]]s dating from [[circa|ca.]] 500 BC to 500 AD that depict guinea pigs have been unearthed in [[archaeology|archaeological]] digs in Peru and Ecuador.<ref>Morales, pp. 3–4.</ref> The [[Moche]] people of ancient Peru worshipped animals and often depicted the guinea pig in their art.<ref>Berrin, Katherine & Larco Museum. ''The Spirit of Ancient Peru:Treasures from the [[Larco Museum|Museo Arqueológico Rafael Larco Herrera]].'' New York: [[Thames and Hudson]], 1997.</ref> From ca. 1200 AD to the [[Spanish conquest of the Inca Empire|Spanish conquest]] in 1532, selective breeding resulted in many varieties of domestic guinea pigs, which form the basis for some of the modern [[domestic varieties of guinea pigs|domestic breeds]].<ref name=walker>{{cite book | last = Nowak | first = Ronald M. | title = Walker's Mammals of the World | edition = 6th edition | date = 1999 | pages = pp. 1667–1669 | isbn = 0-8018-5789-9}}</ref> They continue to be a food source in the region; most households in the Andean highlands raise the animal, which subsists off the family's vegetable scraps.<ref>Morales, p. 8.</ref> [[Folklore]] traditions involving guinea pigs are numerous; they are exchanged as gifts, used in customary social and religious ceremonies, and frequently referenced in spoken [[metaphor]]s.<ref>Morales, pp. 10–16, 45–74.</ref> They also play a role in traditional healing rituals by folk doctors, or ''[[curandero]]s'', who use the animals to [[diagnosis|diagnose]] diseases such as [[jaundice]], [[rheumatism]], [[arthritis]] and [[typhus]].<ref>Morales, p. 96.</ref> They are rubbed against the bodies of the sick, and are seen as a [[supernatural]] medium.<ref>Morales, p. 78.</ref> Black guinea pigs are considered especially useful for diagnoses.<ref>Morales, p. 87-88.</ref> The animal also may be cut open and its entrails examined to determine whether the cure was effective.<ref>Morales, p. 83.</ref> These methods are widely accepted in many parts of the Andes, where [[Western medicine]] is either unavailable or distrusted.<ref>Morales, pp. 75–78.</ref>
[[Spanish Empire|Spanish]], [[Dutch Empire|Dutch]] and [[British Empire|English]] traders brought guinea pigs to [[Europe]], where they quickly became popular as [[exotic pet]]s among the upper classes and royalty, including [[Elizabeth I of England|Queen Elizabeth I]].<ref>Morales, p. 3.</ref> The earliest known written account of the guinea pig dates from 1547, in a description of the animal from [[Santo Domingo]]; because cavies are not native to [[Hispaniola]], the animal must have been introduced there by Spanish travelers.<ref name=weir>{{citation | last = Weir | first = Barbara J. | contribution = Notes on the Origin of the Domestic Guinea-Pig | editor-last = Rowlands | editor-first = I. W. | editor2-last = Weir | editor2-first = Barbara J. | title = The Biology of Hystricomorph Rodents | publisher = Academic Press | date = 1974 | pages = pp. 437–446 | isbn = 0-12-6133334-4}}</ref> The guinea pig was first described in the West in 1554 by the [[Switzerland|Swiss]] naturalist [[Konrad Gesner]].<ref>{{cite book | last = Gmelig-Nijboer | first = C. A. | title = Conrad Gessner's "Historia Animalum": An Inventory of Renaissance Zoology | date = 1977 | publisher = Krips Repro B.V. | pages = pp. 69–70|}}</ref> Its [[binomial nomenclature|binomial]] scientific name was first used by [[Johann Christian Polycarp Erxleben|Erxleben]] in 1777; it is an amalgam of [[Peter Simon Pallas|Pallas]]'s [[generic name|generic]] designation (1766) and [[Linnaeus]]'s [[specific name|specific]] conferral (1758).<ref name=weir/>
== Name ==
The [[binomial nomenclature|scientific name]] of the common species is ''Cavia porcellus'', with ''[[Wiktionary:la:porcus|porcellus]]'' being [[Latin]] for "little pig". ''Cavia'' is [[New Latin]]; it is derived from ''cabiai'', the animal's name in the language of the [[Galibi]] tribes once native to [[French Guiana]].<ref>{{cite web | title = Cavy | publisher = Oxford English Dictionary online (subscription access required) | url = http://dictionary.oed.com | accessdate = 2007-04-25}}</ref> ''Cabiai'' may be an adaptation of the [[Portuguese language|Portuguese]] ''çavia'' (now ''savia''), which is itself derived from the [[Tupian languages|Tupi]] word ''saujá'', meaning rat.<ref>{{cite web | title = Definition of cavy | publisher = Merriam-Webster Online | url = http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=cavy | accessdate = 2007-03-12|}}</ref> Guinea pigs are called ''quwi'' or ''jaca'' in [[Quechua]] and ''cuy'' or ''cuyo'' (pl. ''cuyes, cuyos'') in the [[Spanish language|Spanish]] of Ecuador, Peru and Bolivia.<ref name=diccionario>{{cite web | last = | first = | title = Diccionario de la Lengua Española | publisher = Real Academia Española | url = http://buscon.rae.es/draeI/ | language = Spanish | accessdate = 2007-03-12 }}</ref> Paradoxically, [[Animal fancy|breeders]] tend to use the more formal "cavy" to describe the animal, while in scientific and laboratory contexts it is far more commonly referred to by the more colloquial "guinea pig".<ref name=wagner>{{cite book | last = Wagner | first = Joseph E. | last2 = Manning | first2 = Patrick J | title = The Biology of the Guinea Pig | date = 1976 | publisher = Academic Press | pages = p. 2 | isbn = 0-12-730050-3}}</ref>
How the animals came to be thought of as "pigs" is not clear. They are built somewhat like [[pig]]s, with large heads relative to their bodies, stout necks, and rounded rumps with no tail of any consequence; some of the sounds they emit are very similar to those made by pigs, and they also spend a large amount of time eating.<ref>Wagner, p. 2; Terril, p. 2.</ref> They can survive for long periods in small quarters, like a 'pig pen', and were thus easily transported on ships to Europe.<ref>Wagner, p. 2.</ref>
The animal's name carries [[porcine]] connotations in many European languages. The [[German language|German]] word for them is ''[[Wiktionary:Meerschweinchen|Meerschweinchen]]'', literally "little sea pigs". (The [[Polish language|Polish]] ''świnka morska'' and [[Russian language|Russian]] ''морская свинка'' mean exactly the same.) This derives from [[Age of Discovery|nautical history]]: sailing ships stopping to reprovision in the [[New World]] would pick up stores of guinea pigs, which provided an easily transportable source of fresh meat; ''Schweinswal'' (pig-whale) is German for [[porpoise]], which was another food source for sailors. The [[French language|French]] term is ''[[Wiktionary:fr:cavia|Cochon d'Inde]]'' (Indian pig); the [[Netherlands|Dutch]] used to call it ''[[Wiktionary:nl:cavia|guinees biggetje]]'' (Guinean piglet) or ''Spaanse rat'' (Spanish rat) in some dialects, and in [[Portuguese language|Portuguese]] the guinea pig is sometimes referred to as ''[[Wiktionary:pt:cobaia|porquinho da Índia]]'' (little Indian pig). This is not universal; for example, the common word in Spanish is ''[[Wiktionary:es:conejillo de Indias|conejillo de Indias]]'' (little rabbit of India / the Indies).<ref name=diccionario/>
The origin of "guinea" in "guinea pig" is harder to explain. One theory is that the animals were brought to Europe by way of [[Guinea (region)|Guinea]], leading people to think they had originated there.<ref name=wagner/> "Guinea" was also frequently used in English to refer generally to any far-off, unknown country, and so the name may simply be a colorful reference to the animal's foreignness.<ref name=dictionary>{{ cite web | title = Results for "Guinea pig" | publisher = Dictionary.com | url = http://dictionary.reference.com/browse/Guinea%20pig | accessdate = 2006-08-29 }}</ref> Another theory suggests the "guinea" in the name is a corruption of "[[Guiana]]", an area in [[South America]], though the animals are not native to that region.<ref name=dictionary/><ref>Wagner, pp. 2–3.</ref> A common misconception is that they were so named because they were sold for the price of a [[guinea coin]]; this theory is untenable, because the guinea was first struck in England in 1663, and [[William Harvey]] used the term "Ginny-pig" as early as 1653.<ref>{{cite book | last = Harvey | first = William | title = Anatomical exercitations concerning the generation of living creatures to which are added particular discourses of births and of conceptions, &c | date = 1653 | pages = p. 527|}}</ref> Others believe "guinea" may be an alteration of the word ''[[wiktionary:coney|coney]]'' (rabbit); guinea pigs were referred to as "pig coneys" in [[Edward Topsell]]'s 1607 treatise on [[quadruped]]s.<ref name=wagner/>
== Traits and environment ==
[[Image:Nibbles and strips 2.jpg|thumb|Two parti-colored Abyssinian guinea pigs]]
Guinea pigs are large for rodents, weighing between 700 and 1200[[kilogram|g]] (1.5-2.5 [[Pound (mass)|pound]]s), and measuring between 20 and 25[[metre|cm]] (8–10 [[inch]]es) in length.<ref name=vanderlip>{{cite book | last = Vanderlip | first = Sharon | title = The Guinea Pig Handbook | publisher = Barron's | date = 2003 | pages = p. 13 | isbn = 0-7641-2288-6}}</ref> They typically live an average of four to five years, but may live as long as eight years.<ref name=richardson>{{cite book | last = Richardson | first = V.C.G. | title = Diseases of Domestic Guinea Pigs |edition = 2nd edition | publisher = Blackwell | date = 2000 | pages = pp. 132–133 |isbn = 0-632-05209-0 }}</ref> According to the 2006 [[Guinness Book of Records]] the longest living guinea pig survived 14 years, 10.5 months.<ref>{{cite book | title = Guinness Book of World Records | date = 2006 | publisher = Guinness World Records Ltd. | pages = p. 60 | isbn = 1-904994-02-4|}}</ref>
In the 1990s, a [[Rodent#Monophyly or polyphyly?|minority scientific opinion emerged]] proposing that [[caviomorph]]s, such as guinea pigs, [[chinchilla]]s and [[degu]]s, are not rodents and should be [[taxonomy|reclassified]] as a separate [[order (biology)|order]] of mammals (similar to [[lagomorph]]s).<ref>{{cite journal | last = Graur | first = D., et al | title = Is the Guinea-Pig a Rodent? | date = 1991 | journal = [[Nature (journal)|Nature]] | volume = 351 | pages = pp. 649–652 | doi = 10.1038/351649a0}}</ref><ref>{{cite journal | last = D'Erchia | first = A., et al | title = The Guinea Pig is Not a Rodent | date = 1996 | journal = [[Nature (journal)|Nature]] | volume = 381 | pages = pp. 597–600 | doi = 10.1038/381597a0}}</ref> Subsequent research using wider sampling has restored consensus among mammalian biologists that the current classification of rodents as [[monophyly|monophyletic]] is justified.<ref>{{citation | last = Carleton | first = Michael D. | last2 = Musser | first2 = Guy G. | contribution = Order Rodentia | editor-last = Wilson | editor-first = Don E. | editor-last2 = Reeder | editor-first2 = DeeAnn M. | title = Mammal Species of the World | edition = 3rd | date = 2005 | volume = 2 | pages = p. 745 | publisher = Johns Hopkins University Press | isbn = 0-8018-8221-4}}</ref><ref>{{cite journal | last = Huchon | first = D., et al | url = http://www.pnas.org/cgi/content/abstract/104/18/7495 | title = Multiple molecular evidences for a living mammalian fossil | date = 2007 | journal = [[PNAS]] | volume = 104 | pages = pp. 7495–7499 | doi = 10.1073/pnas.0701289104 | pmid = 17452635}}</ref>
=== Natural habitat ===
''Cavia porcellus'' is not found naturally in the wild; it is likely descendant from some closely related species of [[cavia|cavies]], such as ''[[Cavia aperea]]'', ''[[Cavia fulgida]]'', and ''[[Cavia tschudii]]'', which are still commonly found in various regions of South America.<ref name=weir/> Some species of cavy identified in the 20th century, such as ''[[Cavia anolaimae]]'' and ''[[Cavia guianae]]'', may be domestic guinea pigs that have become [[feral]] by reintroduction into the wild.<ref name=walker/> Wild cavies are found on grassy plains and occupy an [[ecological niche]] similar to that of the [[cattle|cow]]. They are social, living in the wild in small groups which consist of several females (sows), a male (boar), and the young (which in a break with the preceding [[pig|porcine]] nomenclature are called pups). They move together in groups ([[herds]]) eating grass or other vegetation, and do not store food.<ref name=wagner2>Wagner, pp. 31–32.</ref> While they do not [[burrow]] or build nests, they frequently seek shelter in the burrows of other animals, as well as in crevices and tunnels formed by [[vegetation]].<ref name=wagner2/> They are [[crepuscular]], tending to be most active during dawn and dusk, when it is harder for predators to spot them.<ref name=terril>{{cite book | last = Terril | first = Lizabeth A. | last2 = Clemons | first2 = Donna J. | title = The Laboratory Guinea Pig | publisher = CRC Press | date = 1998 | pages = p. 6 | isbn = 0-8493-2564-1|}}</ref>
=== Domestic habitat ===
Domesticated guinea pigs thrive in groups of two or more; groups of sows, or groups of one or more sows and a neutered boar are common combinations. Guinea pigs learn to recognize and bond with other individual guinea pigs, and testing of boars shows that their [[neuroendocrine]] stress response is significantly lowered in the presence of a bonded female when compared to the presence of unfamiliar females.<ref>{{cite journal | url = http://www.scielo.br/pdf/bjmbr/v37n6/4930.pdf | last = Cohn | first = D.W.H. et al. | title = Female Novelty and the Courtship Behavior of Male Guinea Pigs | journal = Brazilian Journal of Medical and Biological Research | volume = 37 | year = 2004 | pages = 847–851 | doi = 10.1590/S0100-879X2004000600010}}</ref> Groups of boars may also get along, provided that their cage has enough space, they are introduced at an early age, and no females are present.<ref>Vanderlip, pp. 33–34.</ref> Domestic guinea pigs have developed a different biological rhythm from their wild counterparts, and have longer periods of activity followed by short periods of sleep in between.<ref name=terril/> Activity is scattered randomly over the 24 hours of the day; aside from avoidance of intense light, no regular [[circadian rhythm|circadian]] patterns are apparent.<ref name=terril/> [[Image:Cat and guinea pigs.jpg|thumb|left|220px|This cat has accepted this pair of guinea pigs. The success of this type of interspecies interaction varies according to the individual animals involved]]
Domestic guinea pigs generally live in cages, although some owners of large numbers of guinea pigs will dedicate entire rooms to their pets. Cages with solid or wire [[mesh]] floors are used, although wire mesh floors can cause injury and may be associated with an infection commonly known as [[bumblefoot (infection)|bumblefoot]] (ulcerative pododermatitis).<ref>Richardson, pp. 63–64.</ref> "Cubes and [[Coroplast]]" (or C&C) style cages are now a common choice.<ref name=ygph>{{ cite web | title = Your Guinea Pigs' Home | publisher = Guinea Pig Cages | url = http://www.guineapigcages.com | accessdate = 2006-08-29 }}</ref> Cages are often lined with wood shavings or a similar material. Bedding made from [[red cedar]] and [[pine]], both [[softwood]]s, was commonly used in past decades, but these materials are now believed to contain harmful [[phenol]]s (aromatic hydrocarbons) and oils.<ref name=terril2>Terril, p. 34.</ref> Safer beddings include those made from [[hardwoods]] (such as [[aspen]]); paper products and corn cob materials are other alternatives.<ref name=terril2/> Guinea pigs tend to be messy within their cages; they often jump into their food bowls or kick bedding and feces into them, and their [[urine]] crystallizes on cage surfaces and can be difficult to remove.<ref>Vanderlip, pp. 44, 49.</ref> After its cage has been cleaned, a guinea pig will typically urinate and drag the lower body across the floor of the cage to mark its territory.<ref name=nrc>{{cite book | last = National Resource Council | title = Laboratory Animal Management: Rodents | publisher = National Academy Press | date = 1996 | pages = pp. 72–73 | isbn = 0-309-04936-9|}}</ref> Male guinea pigs may also mark their territory in this way when they are taken out of their cages.
Guinea pigs do not generally thrive when housed with other species. Cohousing of guinea pigs with other rodents such as [[gerbil]]s and [[hamster]]s may increase instances of respiratory and other infections,<ref>Wagner, p. 122.</ref> and such rodents may act aggressively toward the guinea pig.<ref>Vanderlip, p. 19.</ref> Larger animals may regard guinea pigs as [[prey]], though some (such as [[dog]]s) can be trained to accept them.<ref name=behrend>{{cite book | last = Behrend | first = Katrin | title = Guinea Pigs: A Complete Pet Owner's Manual | date = 1998 | publisher = Barron's | pages = pp. 22–23 | isbn = 0-7641-0670-8}}</ref> Guinea pigs can be safely housed with [[degu]] as they share the same dietary needs and have similar behavioural traits. Opinion is divided over the cohousing of guinea pigs and [[domestic rabbit]]s. Some published sources say that guinea pigs and rabbits complement each other well when sharing a cage.<ref name=behrend/><ref>Vanderlip, p. 20.</ref> However, as [[Lagomorpha|lagomorphs]], rabbits have different nutritional requirements, and so the two species cannot be fed the same food.<ref name=terril3>Terril, p. 41.</ref> Rabbits may also harbor diseases (such as the respiratory infections ''[[Bordetella]]'' and ''[[Pasteurella]]''), to which guinea pigs are susceptible.<ref>Wagner, pp. 126–128.</ref> Even the [[dwarf rabbit]] is much stronger than the guinea pig and may cause intentional or inadvertent injury.<ref name=gpc>{{cite web | url = http://www.guineapigcages.com/rabbits.htm | title = Rabbits & Other Pets | publisher = Guinea Pig Cages | accessdate = 2007-04-03}}</ref>
=== Behavior ===
Guinea pigs can learn complex paths to food, and can accurately remember a learned path for months. Their strongest and overwhelming problem solving strategy is 'activity'<ref>{{cite journal | last = Charters | first = Jessie Blount Allen | title = The associative processes of the guinea pig: A study of the psychical development of an animal with a nervous system well medullated at birth | journal = Journal of comparative neurology and psychology | volume = XIV | issue = 4 | pages = pp. 300–337 | publisher = University of Chicago | date = July 1904 | url = http://books.google.com/books?vid=OCLC16980230&id=dWcKAAAAMAAJ&pg=RA2-PA300&lpg=RA2-PA300&dq=guinea+pigs#PRA1-PA299,M2 | accessdate = 2006-12-27 }}</ref> While guinea pigs can jump small obstacles, they cannot climb, and are not particularly agile. They startle extremely easily, and will either freeze in place for long periods or run for cover with rapid, darting motions when they sense danger.<ref name=terril/> Larger groups of startled guinea pigs will "stampede", running in haphazard directions as a means of confusing predators.<ref>Wagner, p. 34.</ref> When excited, guinea pigs may repeatedly perform little hops in the air (known as "popcorning"), a movement analogous to the ferret's [[weasel war dance|war dance]].<ref>{{ cite web | title = Guinea Pigs | publisher = Canadian Federation of Humane Societies | url = http://cfhs.ca/athome/guinea_pigs | accessdate = 2007-03-21 }}</ref> They are also exceedingly good swimmers.<ref name=harkness>{{cite book | last = Harkness | first = John E. | last2 = Wagner | first2 = Joseph E. | title = The Biology and Medicine of Rabbits and Rodents | publisher = Williams & Wilkins | date = 1995 | pages = pp. 30–39 | id = ISBN 0-683-03919-9}}</ref>
Like many rodents, guinea pigs sometimes participate in [[social grooming]], and they regularly self-groom.<ref>Vanderlip, p. 79.</ref> A milky-white substance is secreted from their eyes and rubbed into the hair during the grooming process.<ref>Richardson, p. 72.</ref> Groups of boars will often chew each other's hair, but this is a method of establishing hierarchy within a group, rather than a social gesture.<ref name=harkness/> Dominance is also established through biting (especially of the ears), [[Goose bumps|piloerection]], aggressive noises, head thrusts, and leaping attacks.<ref>Wagner, p. 38.</ref> Non-sexual simulated [[mount]]ing for dominance is also common among same-sex groups.
Guinea pigs have poor sight, but well-developed senses of hearing, [[olfaction|smell]], and touch.<ref>Wagner, pp. 32–33; Vanderlip, p. 14.</ref> Vocalization is the primary means of communication between members of the species.<ref>Terril, p. 7.</ref> Some sounds are:<ref>Terril, pp. 7–8.</ref><ref name=jackie>{{cite web | title = Guinea Pig Sounds | publisher = Jackie's Guinea Piggies | url = http://jackiesguineapiggies.com/guineapigsounds.html | accessdate = 2007-03-14|}} Includes sound files.</ref>
* '''Wheek''' - A loud noise, the name of which is [[onomatopoeia|onomatopoeic]], also known as a '''Whistle'''. An expression of general excitement, it may occur in response to the presence of its owner or to feeding. It is sometimes used to find other guinea pigs if they are running. If a guinea pig is lost, it may wheek for assistance. {{Audio|Guinea Pig Feeding Wheek.ogg|listen}}
* '''Bubbling''' or '''Purring''' - This sound is made when the guinea pig is enjoying itself, such as when being petted or held. They may also make this sound when grooming, crawling around to investigate a new place, or when given food. {{Audio|Guinea Pig Happy.ogg|listen}}
* '''Rumbling''' - This sound is normally related to dominance within a group, though it can also come as a response to comfort or contentment. While courting, a male usually purrs deeply, swaying and circling the female<ref>Wagner, p. 39.</ref> in a behavior called "rumblestrutting". {{Audio|Guinea Pig Keep Away.ogg|listen}}
* '''Chutting''' and '''Whining''' - These are sounds made in pursuit situations, by the pursuer and pursuee, respectively. {{Audio|Guinea Pig Angry.ogg|listen}}
* '''Chattering''' - This sound is made by rapidly gnashing the teeth, and is generally a sign of warning. Guinea pigs tend to raise their heads when making this sound.
* '''Squealing''' or '''Shrieking''' - A high-pitched sound of discontent, in response to pain or danger. {{Audio|Guinea Pig In Distress.ogg|listen}}
* '''Chirping''' - This less-common sound, likened to [[bird song]], seems to be related to stress, or when a baby guinea pig wants to be fed. Very rarely, the chirping will last for several minutes. {{Audio|Guinea Pig Chirping.ogg|listen}}
== Breeding ==
[[Image:Fat Adie pictures 001.jpg|thumb|left|Pregnant sow one week before delivering three pups]]
The guinea pig is able to breed year-round, with birth peaks usually coming in the spring; as many as five litters can be produced per year.<ref name=walker/> The [[gestation]] period lasts from 59–72 days, with an average of 63–68 days.<ref name=nrc/> Because of the long gestation period and the large size of the pups, pregnant females may become large and [[aubergine]]-shaped, although the change in size and shape varies. Newborn pups are well-developed with hair, teeth, claws and partial eyesight;<ref name=harkness/> they are immediately mobile, and begin eating solid food immediately, though they continue to [[suckle]]. [[Litter (animal)|Litters]] yield 1–6 pups, with an average of three;<ref name=richardson/> the largest recorded litter size is 17.<ref>{{cite book | date = 2007 | title = Guinness Book of World Records | publisher = Guinness World Records Ltd. | pages = p. 127 | id = ISBN 9781904994121}}</ref> In smaller litters, difficulties may occur during labour due to over-sized pups. Large litters result in higher incidences of [[stillbirth]], but because the pups are delivered at an advanced stage of development, lack of access to the mother's milk has little effect on the mortality rate of newborns.<ref>Wagner, p. 88.</ref> Cohabitating females assist in mothering duties if lactating.<ref name=percy>{{cite book | last = Percy | first = Dean H. | last2 = Barthold | first2 = Stephen W. | title = Pathology of Laboratory Rodents and Rabbits | publisher = Iowa State University Press | edition = 2nd edition | date = 2001 | pages = pp. 209–247 | id = ISBN 0-8138-2551-2}}</ref>
[[Image:Guinea baby 1.jpg|thumb|Guinea pig pup at eight hours old]]
Male and female guinea pigs do not [[sexual dimorphism|differ in external appearance]] apart from general size. The position of the anus is very close to the genitals in both sexes. Female genitals are distinguished by a Y-shaped configuration formed from a vulvar flap; while the male genitals may look similar with the penis and anus forming a like shape, the penis will protrude if pressure is applied to the surrounding hair.<ref>Richardson, pp. 14, 17.</ref> The male's testes may also be visible externally from scrotal swelling.
Males reach sexual maturity at 3–5 weeks; females can be fertile as early as four weeks and can carry litters before they are adults.<ref>Richardson, pp. 15–16.</ref> Females that have never given birth commonly develop irreversible fusing of the [[pubic symphysis]], a joint in the [[pelvis]], after six months of age.<ref name=nrc/> If they become pregnant after this has happened, the birth canal will not widen sufficiently; this may lead to [[dystocia]] and death as they attempt to give birth.<ref>Richardson, pp. 25–26.</ref> Females can become pregnant 6–48 hours after giving birth, but it is not healthy for a female to be thus constantly pregnant.<ref>Richardson, pp. 17–18.</ref>
[[Toxemia of pregnancy]] is common and kills many pregnant females. Signs of toxemia include anorexia, lack of energy, excessive salivation, a sweet or fruity breath odor due to [[ketone]]s, and [[seizure]]s in advanced cases.<ref>Richardson, pp. 20–21.</ref> Pregnancy toxemia appears to be most common in hot climates.<ref>Richardson, p. 20.</ref> Other serious complications of pregnancy can include a [[prolapse|prolapsed uterus]], [[hypocalcemia]], and [[mastitis]].<ref>Richardson, pp. 25–29.</ref>
== Diet ==
[[Image:Cavy eating grass.jpg|thumb|left|A silver agouti guinea pig eating grass]]
[[Grass]] is the guinea pig's natural diet. Their [[Molar (tooth)|molar]]s are particularly suited for grinding plant matter, and grow continuously throughout the animal's life.<ref>Wagner, p. 228.</ref> Most grass-eating mammals are quite large and have a long digestive tract; while guinea pigs have much longer [[Colon (anatomy)|colon]]s than most rodents, they must also supplement their diet by [[coprophagy]], the eating of their own feces.<ref>Richardson, pp. 50–51.</ref> However, they do not consume all their feces indiscriminately, but produce special soft pellets, called [[cecotrope]]s, which recycle [[B vitamins]], fiber, and bacteria required for proper digestion.<ref>Terril, p. 41; Wagner, p. 236.</ref> The cecotropes (or caecal pellets) are eaten directly from the anus, unless the guinea pig is pregnant or obese.<ref name=terril3/> They share this behaviour with [[rabbit]]s. In older boars (the condition is rarer in young ones), the muscles which allow the softer pellets to be expelled from the anus for consumption can become weak. This creates a condition known as anal impaction, which prevents the boar from redigesting cecotropes, though harder pellets may pass through the impacted mass.<ref>Richardson, p. 52.</ref> The condition may be temporarily alleviated by carefully expelling the impacted feces.
Guinea pigs benefit from feeding on fresh grass hay, such as [[Timothy-grass|timothy hay]], in addition to food pellets which are often based from timothy. [[Alfalfa]] is also a popular food choice; most guinea pigs will eat large amounts of alfalfa when offered it,<ref>Morales, p. 8; Wagner, p. 32.</ref> though there exists some controversy over the feeding of alfalfa to adult guinea pigs. Some pet owners and veterinary organizations have advised that, as a [[legume]] rather than a grass hay, alfalfa consumed in large amounts may lead to [[obesity]], as well as [[bladder stone (animal)|bladder stone]]s due to excess [[calcium]], in any but pregnant and very young guinea pigs.<ref>{{cite web | title = Health, Care, and Diet for a Guinea pig | url = http://www.lakehowellanimalclinic.com/html/guinea_pig.html | publisher = Lake Howell Animal Clinic | accessdate = 2007-02-16}}</ref><ref>{{cite web | title = Guinea Pigs Care Sheet | url = http://www.canyonlakevet.com/guinea-pig.htm | publisher = Canyon Lake Veterinary Hospital | accessdate = 2007-04-02}}</ref> However, published scientific sources mention alfalfa as a source for replenishment of protein, [[amino acid]]s and fiber.<ref>{{cite book | last = Institute for Laboratory Animal Research | title = Nutrient Requirements of Laboratory Animals | edition = 4th edition | publisher = National Academies Press | date = 1995 | pages = p. 106 | url = http://books.nap.edu/openbook/0309051266/gifmid/106.gif | id = ISBN 0309051266 }}</ref><ref>Wagner, p. 236; Terril, p. 39.</ref>
Like [[Homo sapiens|humans]], but unlike most other [[mammal]]s, guinea pigs cannot synthesize their own [[vitamin C]] and must obtain this vital nutrient from food. If guinea pigs do not ingest enough vitamin C, they can suffer from potentially fatal [[scurvy]]. Guinea pigs require about {{convert|10|mg|abbr=on}} of vitamin C daily ({{convert|20|mg|abbr=on}} if pregnant), which can be obtained through fresh, raw fruits and vegetables (such as apple, cabbage, carrot, celery, and spinach) or through dietary supplements.<ref>Richardson, p. 92.</ref> Healthy diets for guinea pigs require a complex balance of calcium, [[magnesium]], [[phosphorus]], [[potassium]], and [[hydrogen ion]]s; adequate amounts of vitamins [[Vitamin E|E]], [[Vitamin A|A]], and [[Vitamin D|D]] are also necessary.<ref>Terril, p. 40.</ref> Imbalanced diets have been associated with [[muscular dystrophy]], [[metastatic calcification]], difficulties with pregnancy, vitamin deficiencies, and teeth problems.<ref>Wagner, pp. 237–257; Richardson, pp. 89–91.</ref> Some sources also suggest{{weasel-inline}} that guinea pigs are especially susceptible to gall and kidney stones, making it important to limit calcium intake in their diet. This may involve limiting or eliminating multi-vitamin supplements and calcium-rich foods (like commercially-produced yogurt drops, spinach or very high proportions of alfalfa).{{Fact|date=February 2008}} Guinea pigs tend to be fickle eaters when it comes to fresh fruits and vegetables, having learned early in life what is and is not appropriate to consume, and their habits are difficult to change after maturity.<ref>Wagner, p. 236; Richardson, pp. 88–89.</ref> They do not respond well to sudden changes in diet; they may stop eating and starve rather than accepting new food types.<ref name=harkness/> A constant supply of hay or other food is generally recommended, as guinea pigs feed continuously and may develop habits such as chewing on their own hair if food is not present.<ref>Richardson, p. 89.</ref> Because guinea pigs' teeth grow constantly, they routinely [[gnaw]], lest their teeth become too large for their mouth, a common problem in [[rodents]].<ref name=ygph/> Guinea pigs will also chew on cloth, paper, plastic, and rubber.
A number of plants are poisonous to guinea pigs, including [[bracken]], [[bryony]], [[buttercup]], [[charlock]], [[deadly nightshade]], [[foxglove]], [[hellebore]], [[hemlock]], [[lily of the valley]], [[mayweed]], [[monkshood]], [[potato]],<!-- potato has not been verified against Richardson --> [[privet]], [[Senecio|ragwort]], [[rhubarb]], [[speedwell]], [[toadflax]] and [[wild celery]].<ref name=richardson3>Richardson, p. 93.</ref> Additionally, any plant which grows from a [[bulb]] (e.g., [[tulip]] and [[onion]]) is normally considered poisonous.<ref name=richardson3/>
== Health ==
[[Image:mvc-872s.jpg|thumb|A parti-colored guinea pig suffering from [[Torticollis]], or wry neck]]
Common ailments in domestic guinea pigs include [[respiratory infection]]s, [[diarrhea]], [[scurvy]] ([[vitamin C]] deficiency, typically characterized by sluggishness), [[abscess]]es due to infection (often in the neck, due to hay embedded in the throat, or from external scratches), and infections by [[lice]], [[mite]]s or [[fungus]].<ref>Richardson, ch. 1, 4, 5, 9.</ref>
Mange mites (''Trixacarus caviae'') are a common cause of hair loss, and other symptoms may also include excessive scratching, unusually aggressive behavior when touched (due to pain), and, in some instances, seizures.<ref>Richardson, pp. 3–4.</ref> Guinea pigs may also suffer from "running lice" (''Gliricola porcelli''), a small white insect which can be seen moving through the hair; the eggs of these lice, which appear as black or white specks attached to the hair, are sometimes referred to as "static lice". Giving a bath with neem oil soap is a gentle and effective way of ridding the pig of lice. Other causes of hair loss can be due to hormonal upsets caused by underlying medical conditions such as [[ovarian cyst]]s.<ref>Richardson, p. 55.</ref>
Foreign bodies, especially small pieces of hay or straw, can become lodged in the eyes of guinea pigs, resulting in excessive blinking, tearing, and in some cases an opaque film over the eye due to [[corneal ulcers in animals|corneal ulcer]].<ref>Richardson, pp. 69–70.</ref> Hay or straw dust will also cause [[sneeze|sneezing]]. While it is normal for guinea pigs to sneeze periodically, frequent sneezing may be a symptom of [[pneumonia (non-human)|pneumonia]], especially in response to atmospheric changes. Pneumonia may also be accompanied by [[torticollis]] and can be fatal.<ref>Richardson, pp. 45–48.</ref>
Because the guinea pig has a stout, compact body, the animal more easily tolerates excessive cold than excessive heat.<ref name=wagner3>Wagner, p. 6.</ref> Its normal [[body temperature]] is 101–104 °F (38.5–40 °C),<ref>Terril, p. 19.</ref> and so its ideal ambient air temperature range is similar to the [[room temperature|human's]], about 65–75 °F (18–24 °C).<ref name=wagner3/> Consistent ambient temperatures in excess of 90 °F (32 °C) have been linked to [[hyperthermia]] and death, especially among pregnant sows.<ref name=wagner3/> Guinea pigs are not well suited to environments that feature wind or frequent drafts,<ref>Terril, p. 37.</ref> and respond poorly to extremes of [[humidity]] outside of the range of 30–70%.<ref>Terril, p. 36.</ref>
Guinea pigs are [[Predation|prey]] animals whose survival instinct is to mask pain and signs of illness, and many times health problems may not be apparent until a condition is severe or in its advanced stages. Treatment of disease is made more difficult by the extreme sensitivity guinea pigs have to most [[antibiotic]]s, including [[penicillin]], which kill off the [[intestinal flora]] and quickly bring on episodes of diarrhea and in some cases, death.<ref>Wagner, p. 229; Richardson, pp. 105–106.</ref>
Similar to the inherited [[genetic diseases]] of other breeds of animal (such as [[hip dysplasia]] in canines), a number of genetic abnormalities of guinea pigs have been reported. Most commonly, the [[roan (color)|roan]] coloration of [[domestic varieties of guinea pigs|Abyssinian]] guinea pigs is associated with [[congenital]] eye disorders and problems with the digestive system.<ref>Richardson, p. 69.</ref> Other genetic disorders include "waltzing disease" (deafness coupled with a tendency to run in circles), [[palsy]], and [[tremor]] conditions.<ref name=robinson>{{citation | last = Robinson | first = Roy | contribution = The Guinea Pig, ''Cavia Porcellus'' | editor-last = King | editor-first = Robert C | title = Handbook of Genetics | volume = 4 | date = 1974 | pages = pp. 275–307 | publisher = Plenum | id = ISBN 0-306-37614-8}}</ref>
== Pets ==
{{main|Guinea pig breed}}
[[Image:Cavia porcellus 002.jpg|thumb|right|A guinea pig being held]]
If handled correctly early in their life, guinea pigs become amenable to being picked up and carried, and seldom bite or scratch.<ref name=harkness/> They are timid explorers, and rarely attempt to escape from their cages, even when an opportunity presents itself.<ref>Vanderlip, p. 20.</ref> Guinea pigs who become familiar with their owner will whistle on the owner's approach; they will also learn to whistle in response to the rustling of plastic bags or the opening of refrigerator doors, where their food is stored.
[[Domestication|Domesticated]] guinea pigs come in many breeds, which have been developed since their introduction to [[Europe]] and [[North America]]. These varieties vary in hair and color composition. The most common varieties found in pet stores are the English shorthair (also known as the American), which have a short, smooth coat, and the Abyssinian, whose coat is ruffled with [[cowlick]]s, or [[rosette (zoology)|rosette]]s. Also popular among breeders are the Peruvian and the Sheltie (or Silkie), both straight longhair breeds, and the [[Texel Guinea Pig|Texel]], a curly longhair.
Cavy Clubs and Associations dedicated to the showing and breeding of guinea pigs have been established worldwide. The American Cavy Breeders Association, an adjunct to the [[American Rabbit Breeders Association]], is the governing body in the United States and Canada.<ref>{{cite web | title = Constitution | url = http://www.acbaonline.com/constitution.html | publisher = American Cavy Breeders Association | date = [[2006-09-29]] | accessdate = 2007-03-22}}</ref> The [[British Cavy Council]] governs cavy clubs in the United Kingdom. Similar organizations exist in [[Australia]] (Australian National Cavy Council)<ref>{{cite web | url = http://ancc0.tripod.com/ | title = Official Website | publisher = Australian National Cavy Council | accessdate = 2007-04-03}}</ref> and [[New Zealand]] (New Zealand Cavy Club).<ref>{{cite web | url = http://www.cavy.wellington.net.nz/ | title = Official Website | publisher = New Zealand Cavy Club | accessdate = 2007-04-03}}</ref> Each club publishes its own Standard of Perfection and determines which breeds are eligible for showing.
[[Image:rene2.jpg|thumb|left|A lilac, orange and white Satin Peruvian guinea pig (show-length coat)]]
As a result of their widespread popularity in human domestic life, and especially because of their popularity in households with children, guinea pigs have shown a presence in culture and media. Some noted appearances of the animal in [[literature]] are ''[[The Fairy Caravan]]'', a novel by [[Beatrix Potter]],<ref>{{cite book | last = Potter | first = Beatrix | title = The Fairy Caravan | date = 1929 | publisher = David McKay Co |}}</ref> and [[Michael Bond]]'s [[Olga da Polga]] series for children,<ref>{{cite book | last = Bond | first = Michael | title = The Tales of Olga da Polga | publisher = Macmillan | date = 2001 | id = ISBN 0-19-275130-1 |}}</ref> both of which feature guinea pigs as the central [[protagonist]]. Another appearance is in ''[[The Magician's Nephew]]'' by [[C. S. Lewis]]: in the first (chronologically) of his ''[[The Chronicles of Narnia]]'' series, a guinea pig is the first creature to travel to the [[Wood between the Worlds]].<ref>{{cite book | last = Lewis | first = C.S. | title = The Magician's Nephew | publisher = Macmillan | date = 1955 | }}</ref> The short story ''[[Pigs is Pigs]]'' by [[Ellis Parker Butler]] is a tale of [[bureaucratic]] incompetence; two guinea pigs held at a [[train station]] breed unchecked while humans argue as to whether they are "pigs" for the purpose of determining freight charges.<ref>{{cite book | last = Butler | first = Ellis Parker | title = Pigs is Pigs | publisher = McClure, Phillips & Co | date = 1906}}</ref>
Guinea pigs have also been featured in film and television. A guinea pig named Rodney, voiced by [[Chris Rock]], was a prominent character in the 1998 film ''[[Dr. Dolittle (film)|Dr. Dolittle]]'' and Lenny the Guinea pig is a co-star on [[Nick Jr]]'s ''[[Wonder Pets]]''. Guinea pigs were used in some major [[advertisement|advertising campaign]]s in the 1990s and 2000s, notably for [[Egg Banking plc]],<ref>{{cite web | url = http://www.egg.com/visitor/0,,3_81609--View_1710,00.html | title = Advertisements | publisher = [[Egg Banking plc]] | accessdate = 2007-07-18|}}</ref> [[Snapple]], and [[Blockbuster Video]].<ref>{{cite web | last = LaMonica | first = Paul | title = Super Bowl Ads, Like the Game, Disappoint | publisher = [[AOL]] Money & Finance | url = http://money.aol.com/news/articles/_a/super-bowl-ads-like-the-game-disappoint/20070205081409990001?cid=403 | date = [[2007-02-04]] | accessdate = 2007-07-19|}}</ref> The Blockbuster campaign is considered by some guinea pig advocates to have been a factor in the rise of cohousing guinea pigs and rabbits.<ref name=gpc/>
== Scientific research ==
The use of guinea pigs in scientific experimentation dates back at least to the 17th century, when the Italian biologists [[Marcello Malpighi]] and [[Carlo Fracassati]] conducted [[vivisection]]s of guinea pigs in their examinations of [[anatomy|anatomic]] structures.<ref>{{cite book | last = Guerrini | first = Anita | title = Experimenting with Humans and Animals | publisher = Johns Hopkins | date = 2003 | pages = p. 42 | id = ISBN 0-8018-7196-4|}}</ref> In 1780, [[Antoine Lavoisier]] used a guinea pig in his experiments with the [[calorimeter]], a device used to measure heat production. The heat from the guinea pig's respiration melted snow surrounding the calorimeter, showing that respiratory gas exchange is a [[combustion]], similar to a candle burning.<ref>{{cite journal | last = Buchholz | first = Andrea C | last2 = Schoeller | first2 = Dale A. | title = Is a Calorie a Calorie? | url = http://www.ajcn.org/cgi/content/full/79/5/899S | journal = American Journal of Clinical Nutrition | volume = 79 | pages = pp. 899S–906S |date = 2004 | accessdate=2007-03-12 | pmid = 15113737 | doi = 10.1186/1475-2891-3-9}}</ref> Guinea pigs played a major role in the establishment of [[germ theory]] in the late 19th century, through the experiments of [[Louis Pasteur]], [[Émile Roux]], and [[Robert Koch]].<ref>Guerrini, pp. 98–104.</ref> Guinea pigs have been [[animals in space|launched into orbital space-flight]] several times, first by the [[USSR]] on the [[Sputnik 9]] [[biosatellite]] of [[March 9]] [[1961]] - with a successful recovery.<ref>{{cite web | last = Gray | first = Tara | url=http://history.nasa.gov/animals.html | title = A Brief History of Animals in Space | publisher = [[National Aeronautics and Space Administration]] | date = 1998 | accessdate = 2007-05-03}}</ref> [[China]] also launched and recovered a biosatellite in 1990 which included guinea pigs as passengers.<ref>{{cite web | url = http://www.cnn.com/2003/TECH/space/10/03/china.space.timeline/ | title = Timeline: China's Space Quest | publisher = [[CNN|CNN.com]] | date = [[2004-01-05]] | accessdate = 2007-05-03}}</ref>
In [[English language|English]], the term ''guinea pig'' is commonly used as a metaphor for a subject of scientific experimentation. This dates back to the early 20th century; the [[Oxford English Dictionary]] notes its first usage in this capacity in 1913.<ref>{{cite web | title = Guinea-pig | publisher = Oxford English Dictionary online (subscription access required) | url = http://dictionary.oed.com | accessdate = 2007-02-22}}</ref> In 1933, [[Consumers' Research]] founders [[F. J. Schlink]] and [[Arthur Kallet]] wrote a book entitled ''100,000,000 Guinea Pigs'', extending the metaphor to consumer society.<ref>{{cite book | last = Kallet | first = Arthur | last2 = Schlink | first2 = F. J. | title = 100,000,000 Guinea Pigs:Dangers in Everyday Foods, Drugs, and Cosmetics | publisher = Vanguard Press | date = 1933 | id = ISBN 978-0405080258 }}</ref> The book became a national bestseller in the United States, thus further popularizing the term, and spurred the growth of the [[consumer protection]] movement.<ref>{{Citation | last = McGovern | first = Charles | contribution = Consumption | editor-last = Whitfield | editor-first = Stephen J. | title = A Companion to 20th-Century America | year = 2004 | pages = p. 346 | publisher = Blackwell | id = ISBN 0-631-21100-4}}</ref> The negative connotation of the term was later employed in the novel ''[[The Guinea Pigs]]'' by [[Czechs|Czech]] author [[Ludvík Vaculík]] as an allegory for [[Soviet]] [[totalitarianism]].<ref>{{cite book | last = Vaculík | first = Ludvík | title = The Guinea Pigs | publisher = Third Press | date = 1973 | id = ISBN 978-0893880606 }}</ref>
[[Image:Inoculating-guineapig.jpg|thumb|right|A guinea pig being [[Inoculation|inoculated]]]]
Guinea pigs were popular laboratory animals until the later 20th century; about 2.5 million guinea pigs were used annually in the U.S. for research in the 1960s,<ref name=gad>{{cite book | last = Gad | first = Shayne C. | title = Animal Models in Toxicology | publisher = Taylor & Francis | date = 2007 | edition = 2nd edition | pages = pp. 334–402 | id = ISBN 0-8247-5407-7|}}</ref> but that total decreased to about 375,000 by the mid-1990s.<ref name=harkness/> As of 2007, they constitute approximately 2% of the current total of laboratory animals.<ref name=gad/> In the past they were widely used to standardize [[vaccine]]s and [[antiviral drug|antiviral agent]]s; they were also often employed in studies on the production of [[antibody|antibodies]] in response to extreme [[allergy|allergic reaction]]s, or [[anaphylaxis]].<ref name=reid>{{cite book | last = Reid | first = Mary Elizabeth | title = The Guinea Pig in Research | date = 1958 | publisher = Human Factors Research Bureau | pages = pp. 62–70|}}</ref> Less common uses included research in [[pharmacology]] and [[irradiation]].<ref name=reid/> Since the middle 20th century, they have been replaced in laboratory contexts primarily by mice and rats. This is in part because research into the genetics of guinea pigs has lagged behind that of other rodents, although geneticists [[W. E. Castle]] and [[Sewall Wright]] made a number of contributions to this area of study, especially regarding [[biological pigment|coat color]].<ref name=robinson/><ref>Wagner, p. 100.</ref> In 2004, the U.S.'s [[National Human Genome Research Institute]] announced plans to sequence the [[genome]] of the domestic guinea pig.<ref>{{cite web | title = NHGRI Adds 18 Organisms to Sequencing Pipeline | url = http://www.genome.gov/12511858 | publisher = [[National Institutes of Health]] | date = [[2004-08-04]] | accessdate = 2007-04-25|}}</ref>
The guinea pig was most extensively implemented in research and diagnosis of [[infectious disease]]s.<ref name=reid/> Common uses included identification of [[brucellosis]], [[Chagas disease]], [[cholera]], [[diphtheria]], [[foot-and-mouth disease]], [[glanders]], [[Q fever]], [[Rocky Mountain spotted fever]], and various strains of [[typhus]].<ref name=reid/> They are still frequently used to diagnose [[tuberculosis]], since they are easily infected by human tuberculosis bacteria.<ref name=gad/> Because guinea pigs are one of the few animals which, like humans, cannot synthesize [[vitamin C]] but must obtain it from their diet, they are ideal for researching [[scurvy]].<ref name=gad/> [[Complement system|Complement]], an important component for [[serology]], was first isolated from the blood of the guinea pig.<ref name=gad/> Guinea pigs have an unusual insulin mutation,<ref>{{cite journal | last = Chan | first = Shu Jin, et al. | title = Guinea Pig Preproinsulin Gene: An Evolutionary Compromise? | journal = [[Proceedings of the National Academy of Sciences]] USA | volume = 81 | date = 1984 | pages = pp. 5046–5050 | doi = 10.1073/pnas.81.16.5046 | pmid = 6591179}}</ref> and are a suitable species for the generation of anti-insulin antibodies.<ref>{{cite journal | last = Bowsher | first = Ronald, et al. | title = Sensitive RIA for the Specific Determination of Insulin Lispro | url = http://www.clinchem.org/cgi/content/full/45/1/104 | journal = Clinical Chemistry | volume = 45 | date = 1999 | pages = pp. 104–110 | accessdate = 2007-03-15 | pmid = 9895345}}</ref> Present at a level 10 times that found in other mammals, the insulin in guinea pigs may be important in growth regulation, a role usually played by [[growth hormone]].<ref>{{cite journal | last = Adkins | first = Ronald, et al. | title = Molecular Phylogeny and Divergence Time Estimates for Major Rodent Groups: Evidence from Multiple Genes | url = http://mbe.oxfordjournals.org/cgi/content/full/18/5/777 | journal = Molecular Biology and Evolution | volume = 18 | date = 2001 | pages = pp. 777–791 | accessdate = 2007-04-25 | pmid = 11319262}}</ref> Additionally, guinea pigs have been identified as [[model organism]]s for the study of [[juvenile diabetes]] and, because of the frequency of pregnancy toxemia, of [[preeclampsia]] in human females.<ref name=percy/>
Guinea pig [[strain (biology)|strain]]s used in scientific research are primarily outbred strains. Aside from the common American or English stock, the two main outbred strains in laboratory use are the Hartley and Dunkin-Hartley; these English strains are [[albino]], although pigmented strains are also available.<ref name=terril4>Terril, pp. 2–3.</ref> [[Inbred strain]]s are less common and are usually used for very specific research, such as immune system molecular biology. Of the inbred strains that have been created, the two that are still used with any frequency are, following Sewall Wright's designations, "Strain 2" and "Strain 13".<ref name=robinson/><ref name=terril4/> The modern "[[Skinny pig]]" hairless and [[immunodeficient]] breed was the result of a spontaneous genetic mutation in inbred laboratory strains from the Hartley stock at the [[Eastman Kodak Company]] in 1979, and henceforth was deliberately reproduced by [[Charles River Laboratories]].<ref>{{cite web | last = Banks | first = Ron | url = http://netvet.wustl.edu/species/guinea/guinpig.txt | title = The Guinea Pig: Biology, Care, Identification, Nomenclature, Breeding, and Genetics | publisher = [[USAMRIID]] Seminar Series | date = [[1989-02-17]] | accessdate = 2007-05-23}}</ref>
== As food ==
<!-- This section is the target of an [[internal link]] from [[Taboo food and drink]] -->
[[Image:Roast Guinea Pig.jpg|thumb|left|Two [[Peruvian]] dishes of cuy meat]]
Guinea pigs (called ''cuy'', ''cuye'', ''curí'') were originally domesticated for their meat in the [[Andes]]. Traditionally, the animal was usually reserved for ceremonial meals by indigenous people in the Andean highlands, but since the 1960s it has become more socially acceptable for consumption by all people.<ref>Morales, p. 47. </ref> It continues to be a major part of the diet in [[Peru]] and [[Bolivia]], particularly in the [[Andes Mountains]] highlands; it is also eaten in some areas of [[Ecuador]] (mainly in the [[Geography of Ecuador#La Sierra (the highlands)|Sierra]]) and [[Colombia]].<ref>Morales, pp. xxvi, 4, 32.</ref> Because guinea pigs require much less room than traditional [[livestock]] and reproduce extremely quickly, they are a more profitable source of food and income than many traditional stock animals, such as pigs and cows;<ref name=Africa>{{cite journal | last = Nuwanyakpa | first = M. et al. | title = The current stage and future prospects of guinea pig production under smallholder conditions in West Africa | journal = Livestock Research for Rural Development | date = November 1997 | volume = 9 | issue = 5 | url = http://www.cipav.org.co/lrrd/lrrd9/5/gp951.htm | accessdate = 2007-04-16}}</ref> moreover, they can be raised in an urban environment. Both rural and urban families raise guinea pigs for supplementary income, and the animals are commonly bought and sold at local markets and large-scale municipal fairs.<ref>Morales, pp. 32–43.</ref>
Guinea pig meat is high in [[protein]] and low in [[fat]] and [[cholesterol]], and is described as being similar to [[rabbit]] and the dark meat of [[chicken (food)|chicken]].<ref name=cbs/><ref name=csmonitor>{{cite news | last = Mitchell | first = Chip | title = Guinea Pig: It's What's for Dinner | publisher = [[Christian Science Monitor]] | url= http://www.csmonitor.com/2006/1101/p04s01-woam.html | date = [[2006-11-01]] | accessdate = 2007-03-12|}}</ref> The animal may be served fried (''chactado'' or ''frito''), broiled (''asado''), or roasted (''al horno''), and in urban restaurants may also be served in a [[casserole]] or a [[fricassee]].<ref name=morales2>Morales, pp. 48–67.</ref> Ecuadorians commonly consume ''sopa'' or ''locro de cuy'', a soup dish.<ref name=morales2/> ''[[Pachamanca]]'' or ''[[huatia]]'', a process similar to [[barbecue]]ing, is also popular, and is usually served with corn beer (''[[chicha]]'') in traditional settings.<ref name=morales2/>
[[Image:Cuy in the kitchen edit1.jpg|thumb|Cuy being raised at home in the traditional Andean fashion]]
Peruvians consume an estimated 65 million guinea pigs each year, and the animal is so entrenched in the culture that one famous painting of the [[Last Supper]] in the main cathedral in [[Cusco]] shows [[Christ]] and the twelve disciples dining on guinea pig.<ref name=cbs/> The animal remains an important aspect of certain religious events in both rural and urban areas of Peru. A religious celebration known as ''jaca tsariy'' ("collecting the cuys") is a major festival in many villages in the [[Antonio Raymondi Province|Antonio Raimondi]] province of eastern Peru, and is celebrated in smaller ceremonies in [[Lima, Peru|Lima]].<ref name=morales3>Morales, pp. 101–112.</ref> It is a [[syncretism|syncretistic]] event, combining elements of [[Catholicism]] and [[pre-Columbian]] religious practices, and revolves around the celebration of local [[patron saint]]s.<ref name=morales3/> The exact form that the ''jaca tsariy'' takes differs from town to town; in some localities, a ''sirvinti'' (servant) is appointed to go from door to door, collecting donations of guinea pigs, while in others, guinea pigs may be brought to a communal area to be released in a mock [[bullfight]].<ref name=morales3/> Meals such as ''cuy chactado'' are always served as part of these festivities, and the killing and serving of the animal is framed by some communities as a symbolic [[satire]] of local politicians or important figures.<ref name=morales3/> In the [[Tungurahua Province|Tungurahua]] and [[Cotopaxi Province|Cotopaxi]] provinces of central Ecuador, guinea pigs are employed in the celebrations surrounding the feast of [[Corpus Christi (feast)|Corpus Christi]] as part of the ''Ensayo'', which is a community meal, and the ''Octava'', where ''castillos'' (greased poles) are erected with prizes tied to the crossbars, from which several guinea pigs may be hung.<ref>Morales, pp. 119–126.</ref> The Peruvian town of [[Churin]] has an annual festival which involves dressing guinea pigs in elaborate costumes for a competition.<ref>{{cite web | url= http://itn.co.uk/news/89319c3295386535197a613d28bcf198.html | title = Peruvians Pig-Out | publisher = [[ITN]] | date = [[2007-07-26]] | accessdate = 2007-07-29}}</ref>
Andean immigrants in [[New York City]] raise and sell guinea pigs for meat, and some ethnic restaurants in major United States cities serve cuy as a delicacy.<ref>Morales, pp. xvii, 133–134.</ref> Peruvian research universities, especially [[La Molina National Agrarian University]], began experimental programs in the 1960s with the intention of breeding larger-sized guinea pigs.<ref>Morales, p. 16.</ref> Subsequent university efforts have sought to change breeding and husbandry procedures in South America, in order to make the raising of guinea pigs as livestock more economically sustainable.<ref>Morales, pp. 16–17.</ref> In the 1990s and 2000s, the university began exporting the larger breed guinea pigs to Europe, [[Japan]], and the United States in the hope of increasing human consumption outside of South America.<ref name = cbs/> Efforts have also been made to introduce guinea pig [[animal husbandry|husbandry]] in developing countries in [[West Africa]].<ref name=Africa/> Nevertheless, as a food source they are still generally considered [[taboo food and drink|taboo]] in North America and Europe; in [[reality television]], guinea pig meat has been consumed as an exotic dish by such Western [[celebrity chef]]s as [[Andrew Zimmern]] (for his show ''[[Bizarre Foods]]'') and [[Anthony Bourdain]] in ''[[Anthony Bourdain: No Reservations|No Reservations]]''.
== See also ==
{{portalpar|Mammals}}
* [[British Cavy Council]]
* [[Peter Gurney]]
* [[Save the Newchurch Guinea Pigs]]
== Footnotes ==
{{reflist|3}}
== References ==
{{refbegin}}
*{{cite book | last = Morales | first = Edmundo | title = The Guinea Pig : Healing, Food, and Ritual in the Andes | publisher = University of Arizona Press | date = 1995 | id = ISBN 0-8165-1558-1 }}
*{{cite book | last = Richardson | first = V.C.G. | title = Diseases of Domestic Guinea Pigs |edition = 2nd edition | publisher = Blackwell | date = 2000 |id = ISBN 0-632-05209-0 }}
*{{cite book | last = Terril | first = Lizabeth A. | last2 = Clemons | first2 = Donna J. | title = The Laboratory Guinea Pig | publisher = CRC Press | date = 1998 | id = ISBN 0-8493-2564-1|}}
*{{cite book | last = Vanderlip | first = Sharon | title = The Guinea Pig Handbook | publisher = Barron's | date = 2003 | id = ISBN 0-7641-2288-6}}
*{{cite book | last = Wagner | first = Joseph E. | last2 = Manning | first2 = Patrick J | title = The Biology of the Guinea Pig | date = 1976 | publisher = Academic Press | id = ISBN 0-12-730050-3}}
{{refend}}
== External links ==
{{wiktionary}}
{{Commons|Cavia porcellus}}
{{Wikispecies|Cavia porcellus}}
{{Wikibooks|Animal Care/Guinea pig}}
* [http://ancc.asn.au Australian National Cavy Council Inc]
* [http://acbaonline.com ACBA - American Cavy Breeders' Association]
* [http://www.fau.edu/research/ovs/VetData/guineapig.php Laboratory Guinea Pig]
* [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=12582 Domestic Guinea Pig Genome Project page at GenBank]
{{Caviidae nav}}
{{featured article}}
[[Category:Guinea pigs| ]]
[[Category:Fauna of Peru]]
[[Category:Domesticated animals]]
[[Category:Ecuadorian cuisine]]
[[Category:Bolivian cuisine]]
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[[Category:Meat]]
[[Category:Model organisms]]
[[Category:Pet rodents]]
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[[ar:خنزير غينيا]]
[[an:Conillet d'Indias]]
[[cs:Morče domácí]]
[[cy:Mochyn cwta]]
[[da:Marsvin (gnaver)]]
[[de:Hausmeerschweinchen]]
[[et:Merisiga]]
[[es:Cavia porcellus]]
[[eo:Kobajo]]
[[fr:Cavia porcellus]]
[[gd:Gearra-mhuc]]
[[gl:Cobaia]]
[[io:Kobayo]]
[[id:Marmut]]
[[it:Cavia porcellus]]
[[pam:Dagis sungsung]]
[[hu:Tengerimalac]]
[[mk:Морско прасе]]
[[ms:Tikus Belanda]]
[[nl:Huiscavia]]
[[ja:テンジクネズミ#.E3.83.A2.E3.83.AB.E3.83.A2.E3.83.83.E3.83.88]]
[[pl:Świnka morska]]
[[pt:Porquinho-da-índia]]
[[qu:Quwi]]
[[ru:Морская свинка]]
[[simple:Guinea pig]]
[[sl:Morski prašiček]]
[[sr:Морско прасе]]
[[fi:Marsu]]
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[[th:กินนี่พิก]]
[[tr:Kobay]]
[[zh:豚鼠]]