The First Evidence of Intermittent Rectal Prolapse in a Wild Chimpanzee (Pan troglodytes).

BACKGROUND

Rectal prolapse in wild chimpanzees has been rarely reported. We document a case of rectal prolapse in a wild young male chimpanzee at Mahale Mountains National Park, Tanzania.

METHODS

An affected young male in the Mahale M group was observed with photographs/video and diagnosed according to operational criteria used in human (Oxford grading system). Cause and course of the prolapse were estimated by a set of longitudinal field data.

RESULTS

An intermittently self-reducing full-thickness rectal prolapse was diagnosed. Protrusion fluctuated within minutes; tenesmus and diarrhea were absent; and the mucosa remained bright red and viable, without necrosis or myiasis. Post-traumatic pelvic-floor/anal-sphincter nerve dysfunction after conspecific bite injury on the buttock was estimated as the cause.

CONCLUSIONS

This is the first report of rectal prolapse in wild chimpanzees. The detailed natural course of this persistent condition without medical intervention provides information relevant to case-specific management decisions in wild apes.