Changes

and Auerbach’s myenteric plexus in the distal colon or rectum². This gives persistent smooth muscle contraction in the affected region and proximal dilation of the colon. A similar pathogenesis is proposed in cats.

and Auerbach’s myenteric plexus in the distal colon or rectum². This gives persistent smooth muscle contraction in the affected region and proximal dilation of the colon. A similar pathogenesis is proposed in cats.

Acquired megacolon is more common than the congenital form, and in cats this is most often idiopathic. The true cause of "idiopathic" megacolon is thought to be an intrinsic defect in colonic smooth muscle function³. Aquired megacolon can occur in both cats and dogs as a sequel to any disease or lesion that interferes with normal defecation: faecal retention caused dilatation of the colon and impairs colonic motility. Causes could include neuromuscular abnormalities (spinal cord disease, intervertebral disk disease, dysautonomia, trauma), metabolic disorders (severe dehydration, hypokalaemia), drug therapy (vincristine, anticholinergics, barium), mechanical obstruction (pelvic fracture malunion, foreign bodies, stricture, anal/rectal atresia) and conditions causeing dyschezia (anal sacculitus, perianal fistula, trauma preventing posturing, procititis). After megacolon has persisted for several months, it is unlikely that normal colonic motility will be restored after resolution of the underlying cause. In many cases, the aetiology of megacolon is not determined.

Acquired megacolon is more common than the congenital form, and in cats this is most often idiopathic. The true cause of "idiopathic" megacolon is thought to be an intrinsic defect in colonic smooth muscle function³. Aquired megacolon can occur in both cats and dogs as a sequel to any disease or lesion that interferes with normal defecation: faecal retention caused dilatation of the colon and impairs colonic motility. Causes could include neuromuscular abnormalities (spinal cord disease, intervertebral disk disease, dysautonomia, trauma), metabolic disorders (severe dehydration, hypokalaemia), drug therapy (vincristine, anticholinergics, barium), mechanical obstruction (pelvic fracture malunion, foreign bodies, stricture, anal/rectal atresia) and conditions causeing dyschezia (anal sacculitus, perianal fistula, trauma preventing posturing, proctitis). After megacolon has persisted for several months, it is unlikely that normal colonic motility will be restored after resolution of the underlying cause. In many cases, the aetiology of megacolon is not determined.

==Signalment==

==Signalment==