Editing Guinea pig (section)

=== Reproduction ===
[[File:Fat Adie pictures 001.jpg|thumb|right|[[Pregnant]] sow one week before delivering three pups]]

Males (boars) reach [[sexual maturity]] in 3–5 weeks. Similarly, females (sows) can be fertile as early as four weeks old and carry litters before becoming fully grown adults.{{sfn|Richardson|2000|pages=15–16}} A sow can breed year-round (with spring being the peak). A sow can have as many as five litters in a year, but six is theoretically possible<!-- 360/60 -->.<ref name="walker" /> Unlike the offspring of most [[rodents]], which are [[altricial]] at birth, newborn cavy pups are [[Precociality|precocial]], and are well-developed with hair, teeth, claws, and partial eyesight.<ref name="harkness" /> The pups are immediately mobile and capable of eating solid food, though they continue to [[breastfeeding|suckle]]. Sows can once again become pregnant 6–48 hours after giving birth, but it is not healthy for a female to be constantly pregnant.{{sfn|Richardson|2000|pages=17–18}}

The [[gestation]] period lasts from {{convert|59|-|72|day|month}}, with an average of {{convert|63|-|68|day|month}}.<ref name="nrc" /> Because of the long gestation period and the large size of the pups, pregnant sows may become large and [[eggplant]]-shaped, although the change in size and shape varies depending upon the size of the litter. [[Litter (animal)|Litter]] size ranges from one to six, with three being the average;{{sfn|Richardson|2000|pages=}} the largest recorded litter size is 9.<ref>{{Cite web |title=Largest litter of guinea pigs |url=https://www.guinnessworldrecords.com/world-records/69437-largest-guinea-pig-litter |access-date=2021-03-15 |website=Guinness World Records |language=en-GB}}</ref> The guinea pig mother only has two nipples, but she can readily raise the more average-sized litters of 2 to 4 pups.<ref name="Merck Veterinarian Manual, 2016">[http://www.merckvetmanual.com/all-other-pets/guinea-pigs/breeding-and-reproduction-of-guinea-pigs Breeding and Reproduction of Guinea Pigs], Merck Veterinarian Manual, Katherine E. Quesenberry, DVM, MPH, DABVP (Avian); Kenneth R. Boschert, DVM, DACLAM, 2016.</ref><ref name="Harkness and Wagner's Biology and Medicine of Rabbits and Rodents, 2010">[https://books.google.com/books?id=SFSXqsWvsMQC&dq=%22despite+having+only+two+nipples%2C+guinea+pigs+can+raise+litters+of+3%2C+4%2C+and+more+young%22&pg=PA55 Harkness and Wagner's Biology and Medicine of Rabbits and Rodents, 5th Edition], John E. Harkness, Patricia V. Turner, Susan VandeWoude, Colette L. Wheler, Iowa, USA: Wiley & Sons, "Ch. 2 Biology and Husbandry," 2010.</ref> In smaller litters, difficulties may occur during [[Childbirth|labour]] due to oversized 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.{{sfn|Wagner|Manning|1976|p=88}}[[File:Guinea baby 1.jpg|thumb|Guinea pig pup at eight hours old|alt=|left]]

Cohabitating females assist in mothering duties if [[Lactation|lactating]];<ref name="percy">{{cite book |last1=Percy |first1=Dean H. |title=Pathology of Laboratory Rodents and Rabbits |last2=Barthold |first2=Stephen W. |publisher=Iowa State University Press |year=2001 |isbn=978-0-8138-2551-9 |edition=2nd |pages=209–247}}</ref> guinea pigs practice [[Alloparenting|alloparental care]], in which a sow may adopt the pups of another. This might take place if the original parents die or are, for some reason, separated from them. This behavior is common and is seen in many other animal species, such as the elephant.<ref>{{cite journal |last1=Riedman |first1=Marianne L. |year=1982 |title=The Evolution of Alloparental Care in Mammals and Birds |journal=The Quarterly Review of Biology |volume=57 |issue=4 |pages=405–435 |doi=10.1086/412936 |s2cid=85378202}}</ref>

<!-- Complications -->[[pre-eclampsia|Toxemia of pregnancy]] (hypertension) is a common problem and kills many pregnant females. Signs of toxemia include anorexia (loss of appetite), [[Lethargy|lack of energy]], [[Salivation|excessive salivation]], a [[Bad breath|sweet or fruity breath odor]] due to [[ketone]]s, and [[seizure]]s in advanced cases.{{sfn|Richardson|2000|pages=20–21}} Pregnancy toxemia appears to be most common in hot climates.{{sfn|Richardson|2000|page=20}} Other serious complications during pregnancy can include a [[prolapse|prolapsed uterus]], [[hypocalcaemia]], and [[mastitis]].{{sfn|Richardson|2000|pages=25–29}}

Females that do not give birth may develop an irreversible fusing or calcified cartilage of the [[pubic symphysis]], a joint in the [[pelvis]], which may occur after six months of age.<ref name="nrc" />{{rp|72–73|date=November 2012}} If they become pregnant after this has happened, the birth canal may not widen sufficiently, which may lead to [[dystocia]] and death as they attempt to give birth.{{sfn|Richardson|2000|pages=25–26}}