Disorder - Megacolon

Organ Systems Involved
Gastrointestinal

Presenting Signs

Idiopathic dilated megacolon is caused by chronic constipation (infrequent or difficult passing of faeces) or obstipation (severe constipation that does not respond to treatment). It is the end-stage condition of colonic dysfunction, resulting in enlargement and poor movement of the colon. Cats with megacolon have a history of repeated episodes of constipation and obstipation. Faeces, which are hard and painful, are passed infrequently or not at all, in or outside of the litter box. Mucus or blood may be passed due to irritation caused by the impacted stool. The affected cat may have diarrhoea occasionally. Vomiting is often associated with straining. Systemic signs including depression, lethargy, lack of appetite, weight loss and dehydration, may be present if the megacolon is unresolved.

Cats at Risk

Middle aged, male cats appear to be at increased risk.

Treatment

Surgical and medical. Medical therapy involves correction of dehydration (e.g. fluid therapy, feeding canned food or wet foods) and metabolic abnormalities. Removal of impacted faeces can be achieved by the use of oral or rectal suppository laxatives (e.g. dioctyl sodium sulfosuccinate, glycerin or bisacodyl), or enemas (e.g. warm tap water, DSS, mineral oil or lactulose). Manual removal may be required. Prokinetic drugs (e.g. cisapride, nizatidine, ranitidine) can stimulate colonic motility and may be useful in the management of megaoesophagus. Colectomy (removal of the colon) is required if cats are unresponsive to medical therapy.

PubMed References
Megacolon

Contributor
Jennifer Go