| '''Perineal hernia''' is the protrusion of pelvic or abdominal viscera through the structures of the weakened or ruptured pelvic diaphragm, causing displacement of the perineal skin. The pelvic diaphragm is composed of the coccygeus, levator ani and external anal sphincter muscles and, due to its proximity to these structures, the rectum is the organ most commonly involved in perineal hernias. Perineal hernias can be unilateral or bilateral and, depending of their location, they can be further classified as dorsal, ventral, sciatic or caudal hernias. The herniated content is contained by the perineal fascia and, since the parietal peritoneum is usually intact, this constitutes a true [[Hernia|hernial sac]]. The sac may contain pelvic or retroperitoneal fat, peritoneal fluid, a deviation, dilation or sacculation of the rectum, a rectal diverticulum, the prostate gland, the urinary bladder (which may be retroflexed) or the small intestine and any of these organs may become [[Hernia|incarcerated or stangulated]]. In cats, the sac frequently only contains the rectum. | | '''Perineal hernia''' is the protrusion of pelvic or abdominal viscera through the structures of the weakened or ruptured pelvic diaphragm, causing displacement of the perineal skin. The pelvic diaphragm is composed of the coccygeus, levator ani and external anal sphincter muscles and, due to its proximity to these structures, the rectum is the organ most commonly involved in perineal hernias. Perineal hernias can be unilateral or bilateral and, depending of their location, they can be further classified as dorsal, ventral, sciatic or caudal hernias. The herniated content is contained by the perineal fascia and, since the parietal peritoneum is usually intact, this constitutes a true [[Hernia|hernial sac]]. The sac may contain pelvic or retroperitoneal fat, peritoneal fluid, a deviation, dilation or sacculation of the rectum, a rectal diverticulum, the prostate gland, the urinary bladder (which may be retroflexed) or the small intestine and any of these organs may become [[Hernia|incarcerated or stangulated]]. In cats, the sac frequently only contains the rectum. |
| The rate of recurrence is around 15% one year after surgical herniorraphy. Cases involving bladder retroflexion have the poorest prognosis and, although cases managed medically may have an acceptable quality of life, there is always a danger that the bladder or another organ will be incarcerated and strangulated in the hernial sac. | | The rate of recurrence is around 15% one year after surgical herniorraphy. Cases involving bladder retroflexion have the poorest prognosis and, although cases managed medically may have an acceptable quality of life, there is always a danger that the bladder or another organ will be incarcerated and strangulated in the hernial sac. |
| *Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) '''BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition)''' ''BSAVA'' | | *Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) '''BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition)''' ''BSAVA'' |
| *Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine (Fourth Edition)''' ''Mosby Elsevier''. | | *Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine (Fourth Edition)''' ''Mosby Elsevier''. |