Vocalization or discomfort at defecation attempts.
No motion passed or small amounts of liquid feces (owner may mistake problem for diarrhea), or very small amounts of very dry and hard feces.
Anorexia.
Depression.
Vomiting.
Clinical signs
Palpation of firm, distended colon.
Frequently dehydrated.
Diagnostic investigation Radiography
See abdominal radiography for technique.
Visualization of distended colon on abdominal radiograph .
May also visualize cause of impaction:
Pelvic malunion .
Rectal mass or extra-intestinal compression.
Other
Digital palpation.
Confirmation of diagnosis Discriminatory Diagnostic features
Signs.
Definitive Diagnostic features
Palpation of impacted colon.
Radiography.
Gross autopsy findings
Expose and examine entire colon by removal of ventral coxal bones by cutting cranially and caudally from each obturator foramen.
Include examination of all pelvic contents, plus coxo-femoral and hindlimb skeleton.
Collect autonomic ganglia, eg coeliacomesenteric ganglion between adrenals and aorta (fix tissue block 1 cm margin around each adrenal, since hard to locate ganglia).
Examine spinal cord and nerves to rule out neurological etiology.
Histopathology findings
See megacolon .
Occasionally colonic ganglia have lymphocytic infiltrate - cause unknown.
Fluid therapy to rehydrate animal (this also has the effect of rehydrating impacted feces).
Serial warm water enemas to soften mass of feces.
Colonic lubrication with water-soluble jelly/water mixture (may need to be administered under sedation ). Lactulose enemas may also be useful.
Standard treatment
Anesthesia and forceps or surgical (in extreme cases) removal of impacted feces if fecal mass fails to soften adequately.
In some cases subtotal colonectomy may be required .
Manage underlying condition where possible.
Prokinetic agents, eg cisapride (1-2 mg/kg PO BID-TID has been suggested as a starting dose - though doses as high as 5 mg/kg PO BID may be necessary).
harder drier feces.
