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| Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000. | | Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000. |
| | | |
− | == Pathology of the Large Intestine == | + | == Pathology == |
| === Developmental Anomalies === | | === Developmental Anomalies === |
| ==== Segmental ==== | | ==== Segmental ==== |
− | describe plus stenosis vs complete (atresia)
| + | Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen. |
| ===== Atresia ani ===== | | ===== Atresia ani ===== |
| + | *A common congenital defect of the lower gastrointestinal tract. |
| + | *Both the anus and rectum can be affected. |
| + | *Occurs in all species but is most often seen in calves and pigs. |
| ===== Atresia coli ===== | | ===== Atresia coli ===== |
| + | *Considered the most common segmental anomaly of the intestine in domestic animals. |
| + | *Can affect in particular the spiral colon of Holstein calves and the small colon of foals. |
| + | ===== Atresia ilei ===== |
| + | *It is less common to see atresia in the small intestine. |
| + | *Mostly seen in calves. |
| + | ==== Persistent Meckel's diverticulum ==== |
| + | *Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac. |
| + | *Is usually an incidental finding though it can be associated with impaction and or intussusception. |
| ==== Megacolon ==== | | ==== Megacolon ==== |
| + | *Occurs in cats, dogs, and pigs. |
| + | *May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses. |
| + | *Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition. |
| + | |
| + | |
| + | '''References''' <br /br> |
| + | |
| + | Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007. |
| + | |
| + | McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007. |
| + | |
| === Physical Disturbances === | | === Physical Disturbances === |
| ==== Obstruction ==== | | ==== Obstruction ==== |