Page 125 - April2022

THE
SIGNIFICANCE
OF GUT
SOUNDS
by Nancy S. Loving, DVM
VETERINARY VIEWS
As we continue to explore basic
vital signs that help you and your veterinarian assess a horse’s health, let’s examine another critical parameter: intestinal activity. This is evaluated by listening to gut sounds using a stethoscope placed in the flank area on both sides of a horse, in each of four quadrants. Normal intestinal sounds are much like human stomach growls that are audible when we are hungry. Normally, two or three waves of intestinal contractions, called borborygmi, can be heard each minute in each quadrant. Intestinal sounds represent the mixing
of intestinal contents and its progressive movement down the intestinal tract at a controlled rate, with some resistance to flow to allow absorption of nutrients and fluid in various portions of the bowel.
CHANGES IN INTESTINAL SOUNDS
• Depressed bowel activity is accompanied by diminished intestinal sounds. Instead of being digested, feed sits in one place and ferments, setting off a domino effect
of problems. Although there may not necessarily be a physical blockage of intestinal contents, a quiet bowel experiences a functional obstruction created by lack of effective intestinal motility.
• Other issues create specific sounds:
• Gas in the bowel sounds similar to the tinkle of a pebble falling down
a well.
• Squeaking noises indicate an attempt
at peristaltic contractions with no progressive movement of material through the bowel.
• Increased activity of the colon is often associated with constipation or an impaction.
• An excess amount of intestinal noise may indicate spasms or hyperactivity due to irritation in the bowel, or efforts to correct an obstruction.
It is possible to “hear” the movement of sand by placing a stethoscope on the abdominal midline at the level of the girth, near the sternum. Sounds heard are similar to the sound of rolling surf on a sandy beach, or sand moving in a paper bag.
Intestinal activity is evaluated by listening to gut sounds using a stethoscope placed in the flank area on both sides of a horse, in each of four quadrants.
THE EFFECTS OF REDUCED BOWEL FUNCTION
Gut sounds may only diminish in one portion of the abdomen rather than being absent altogether, hence the reasoning behind listening to all four quadrants. Stagnant intestinal activity reduces the absorption
of intestinal water and nutrients from the bowel. Then vital fluids are sequestered in
the gut, leading to whole body dehydration. Fluid is leached out of the intestinal contents
of a stagnant bowel, potentially leading to
an impaction. Feces may become sparse in frequency or amount. Or, mucoid strands may coat firm fecal balls, indicating stagnation of the large intestine, which could later lead to impaction colic. In some instances, the bowel may be irritated sufficiently to develop diarrhea which occurs as a consequence of a flaccid colon that offers no resistance to flow of ingesta down the “tube.”
Fermenting feed in a stagnant bowel changes the pH adversely to kill off normal intestinal flora, allowing for overgrowth
of intestinal bacteria. With overgrowth of some comes death of others, with release of
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