Almost all mammal penises have foreskins or prepuce, although in non-human cases the foreskin is usually a sheath (sometimes called the ''preputial sheath'', ''praeputium'' or ''penile sheath'') into which the whole penis is retracted. In

koala The koala or, inaccurately, koala bear (''Phascolarctos cinereus''), is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the ...

s, the foreskin contains naturally occurring bacteria that play an important role in fertilization. In some bat species, the prepuce contains an erectile tissue structure called the ''accessory corpus cavernosus''. Great Dane sheath

During

musth Musth or must (from Persian, )''The Oxford Dictionary and Thesaurus: American edition'', published 1996 by Oxford University Press; p. 984 is a periodic condition in bull (male) elephants characterized by aggressive behavior and accompanied ...

, a male elephant may urinate with the penis still in the sheath, which causes the urine to spray on the hind legs.Sukumar, pp. 100–08. Male dogs have a conspicuous penis sheath. Inguinal cryptorchid 1

In stallions, the retractor penis muscle contracts to retract the

stallion's penis A stallion is a male horse that has not been gelded (castrated). Stallions follow the conformation and phenotype of their breed, but within that standard, the presence of hormones such as testosterone may give stallions a thicker, "cresty" n ...

into the sheath and relaxes to allow the penis to extend from the sheath. The penis sheath of a male axis deer is elongated and urine-stained. When rubbing trees with their horns, these stags sometimes move the penis back and forth rapidly inside its sheath. Male

bison Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised. Of the two surviving species, the American bison, ''B. bison'', found only in North A ...

and

fallow deer ''Dama'' is a genus of deer in the subfamily Cervinae, commonly referred to as fallow deer. Name The name fallow is derived from the deer's pale brown colour. The Latin word ''dāma'' or ''damma'', used for roe deer, gazelles, and antelopes ...

have tufts of fur at the end of their penis sheaths. In rodents, the length of the prepuce is related to urine marking behavior.Maruniak, J. A., Claude Desjardins, and F. H. Bronson.
Adaptations for urinary marking in rodents: Prepuce length and morphology
." Journal of Reproduction and Fertility 44.3 (1975): 567-570.

See also

References

Further reading