− | A small intestinal volvulus occurs in the horse when the intestine rotates on its mesenteric axis through an angle greater than 180<sup>o</sup>, resulting in strangulation. Volvulus may occur as a primary cause of colic or secondarily as a result of another condition such as a lipoma, incarceration within the mesentery or adhesion within the abdomen. | + | A small intestinal (SI)volvulus occurs in the horse when the intestine rotates on its mesenteric axis through an angle greater than 180<sup>o</sup>, resulting in strangulation. The pathogenesis is thought to be due to a segment of hypermotile intestine preceding a segment where peristalsis has ceased, leading to the development of a twist. Volvulus may occur as a primary cause of colic or secondarily as a result of another condition such as a lipoma, incarceration within the mesentery or adhesion within the abdomen. |
− | Foals and yearlings are particularly susceptible to this type of colic. | + | SI volvulus has been reported to be more common in horses less than three years of age, and to be particularly prevalent in foals aged two to four months. Foals and yearlings are particularly susceptible to this type of colic. |