Veterinary Splanchnology and Applied Anotomy

LARGE INTESTINE (DOG)

•  It is 60 to 75 cm long. It has no bands or sacculations.
• The caecum is 12.5 to 15 cm It is situated midway between the right flank and median plane
• It extends as a blind diverticulum from the ileo-colic junction and is kept in a flexuous state by peritoneal folds. It opens cranially in to the colon.
• Colon is attached to the sublumbar region by the mesocolon
• It has three parts corresponding to the ascending, transverse, and descending colon of man
• The first-right part (ascending) is very short passing forwards medial to the duodenum, reaches the pyloric part of the stomach
• Here, it turns to the left crossing the median plane forming the transverse part
• The third-left part (descending) passes back in the sublumbar region ventral to the left kidney and inclines to the median plane to be continued as the rectum
• Colon is of uniform caliber throughout and is devoid of bands and sacculations.
• The rectum is completely covered with peritoneum. At the junction of the rectum and anus the mucous membrane has stratified squamous epithelium and contains the anal glands
• A small opening on either side leads into two lateral anal sacs of the size of a hazel nut containing a dirty grey fatty substance having a peculiar unpleasant odour. (View image)