Colonic Impaction - Dog and Cat

Description

Colonic impaction is inintractable constipation which can occur in all species, including the dog and cat. There are hardened faeces in the colon and a delayed or failure of faecal passage. The cause may be primary,

Chronic cases may progress to Obstipation, the faeces become so hard and dry that defecation is no longer possible and ultimately there is secondary degeneration of the colonic musculature.

Diagnosis

Clinical signs

• Failure to pass faeces
• Tenesmus
• Dyschezia
• Anorexia
• Lethargy
• Vommiting

On abdominal palpation the colon is filled with firm faecal material. Digital rectal examination will reveal hardened faecal balls, there may be a palpable mass or sticture, anal sac disease or perineal hernia depending on the cause.

Ultrasound

Abdominal ultrasound shows a colon imapcted with faecal material. It may also reveal the cause in some cases such as foreign body, colonic mass or stricture.

Radiology

Abdominal radiographs reveal a colon filled with faecal material. Radiographs are not normally needed to make a diagnosis of colonic impaction as it can usually be identified on clinical exam, however in certain cases it can identify the cause. A fractured pelvis, dislocated hip, enlarged prostate and colonic or rectal mases can be found on radiographs.

Treatment

The treatment depends on the severity and duration of the impaction.

Dehydrated patients should receive IV fluid therapy, with correction of any concurrent electrolyte and acid-base abnormalities. A warm water enema can be used to soften and allow the impaction to pass. Laxatives such as Emollient laxatives (docusate sodium), Stimulant laxatives (bisacodyl), saline laxatives and disaccharide laxatives (lactulose) are also beneficial.

Cisapride, a motility modifier is indicated in early cases of megacolon.

Owners should be educated with regard to management. An appropriate wet diet should be fed, dietary supplementation with bran is helpful in some cases, water should be freely available and fresh and activity should be encouraged.

Surgery

Surgical removal of faeces under general anaesthesia is neccessary in severe cases where enemas and laxitives have been unsuccessful. A colectomy is required in cases of obstipation or recurrent cases.