A rectal or anal prolapse is the extrusion (pushing out) of the inner layers of the rectum through the anus. It is a condition in which one or more layers of the rectum are displaced through the anus, the opening which allows digestive waste to leave the body.
The rectum is the end part of large intestine that ends at the anus. It serves to allow digestive waste to leave the body.
The rectal or anal proplase can be classified as complete and incomplete. In a complete rectal prolapse, the anal tissue that protrudes from the rectum can be a few inches long, appearing red or pink in color. In an incomplete, or mucosal, rectal prolapse, the lining of the anal canal is inflamed appearing as a red ring of tissue, but does not protrude completely out of the anus. Incomplete rectal prolapse looks very similar to hemorrhoids.
There is also an internal proplase which occurs when the rectum starts to drop down but does not extend out the anus.
This condition can be due a different causes that include disorders of the digestive, urinary, or genital systems. This condition is most often seen in young puppies less than 6 months to one years old and in older dogs.
There is a slight difference between rectal proplase and anal proplase. When all layers of rectal/anal tissue, along with rectal lining, protrude through the external opening, it is termed as rectal proplase where as protrusion of rectal lining through external anal opening is termed as anal proplase.
The most common symptoms of this condition are straining to defecate and the protrusion of rectal proplase which appears as pink mass. In incomplete proplase, a small portion of the lining of the rectum will be visible during excretion, after which it will subside. In a complete prolapse, there will be a persistent mass of tissue protruding from the anus. In the chronic stages of complete prolapse, this tissue might be black or blue in appearance. The dog may excessively lick the anal area.
