by Brent Mayabb, DVM

While we typically think of disease conditions causing loose stools in dogs and cats, it can also be the result of other factors.  Athletic exertion, stress, boarding, and traveling are examples of things that have been commonly associated with decreased fecal quality in pets.  Stress may decrease the intestinal immune response and allow harmful bacteria to overgrow.   The growth of these bacteria can lead to degradation in stool quality.

We also know that large and giant breed dogs have unique characteristics involving their intestinal anatomy and physiology that result in more fecal moisture normally.  The junctions between their intestinal cells allow minerals to pass back into the intestinal lumen after absorption. The minerals draw water with them, resulting in loose stools.  The colonic transit time is also increased in large and giant breed dogs.

What can we do nutritionally to address these issues and help improve stool quality?  Ingredients classified as "prebiotics" can help these pets.  Consider the lumen of the intestine to be a battlefield between the "bad" bacteria that lead to loose stool and upset the gastrointestinal tract and the "good" bacteria that actually help improve stool quality.  Prebiotics - not to be confused with probiotics - are ingredients that stimulate the growth of beneficial bacteria in the intestinal tract.  (Probiotics are live bacterial cultures, such as those found in some yogurts. They are usually ineffective because they are degraded by the pet's own digestive enzymes.)  Prebiotics' functions include:

• - Promoting growth of the "good" bacteria to help keep the "bad" bacteria in check in the intestinal tract.
• - Improving digestion and absorption.
• - Providing short chain fatty acids to feed the intestinal cells.
• - Stimulating local immunity in the intestinal tract.

Fructooligosaccharides (FOS) and mannanoligosaccharides (MOS) are two common prebiotics used by Royal Canin that can improve stool quality and help maintain overall intestinal health. 

FOS is a fermentable fiber.  It is broken down by bacteria in the intestinal tract into substances called short chain fatty acids (SCFAs).  SCFAs acidify the local environment which makes it more conducive to growth of beneficial bacteria like bifidobacteria and lactobacilli.  The SCFAs can also be directly used by the intestinal cells as a source of energy, and help to preserve the health of mucosal cells of the colon.

MOS also helps tip the balance away from the harmful bacteria in the intestinal tract, but by a different method than FOS.  Mannanoligosaccharide is derived from yeast cell walls.  It binds to pathogenic bacteria to prevent the bacteria from adhering to the intestinal cells.  MOS also acts to directly stimulate mucosal immunity by inciting production of certain antibodies called IgA.

Many diseases may result in loose stool or diarrhea, but normal events in your pet's life can also cause a change in stool quality.  And although any underlying disease needs to be treated in order to help make the stool firmer in disease conditions, nutritional interventions such as the use of prebiotics can help improve the fecal quality as well.