Home Contact Us
Library of Diseases
Genetics Lesson
Other Links







S.I. Bacterial Overgrowth Syndrome     


Common names or abbreviations:

bulletSmall Intestine Bacterial Overgrowth Syndrome

Description or definition:

An overgrowth of the naturally occurring bacteria in the small intestine.  SIBO affects the  function of the intestinal cells and results in symptoms such as intermittent and reoccurring diarrhea.

The bacterial overgrowth that characterizes SIBO can be caused by an underlying condition or disease such as parasites, intestinal obstruction (by a foreign body or tumor), problems with the pancreas, etc.  This is referred to as secondary SIBO.   Bacterial overgrowth can also be a naturally occurring problem in certain breeds such as German Shepherd Dogs.  This is referred to as primary SIBO.  SIBO may be related to lower IgA concentrations in the small intestine.


A veterinarian can test the blood for levels associated with changed bacterial populations and can also analyze a sample of the intestinal contents and culture the bacteria to see if there are too many of a certain kind of bacteria.  The dog is also tested for the common underlying causes of bacterial overgrowth.  If no underlying causes are found, the dog is diagnosed with primary SIBO.

Potential Causes:

There are many factors that can cause or contribute to SIBO including, but not limited to, breed predisposition, family history, parasites, gastrointestinal obstruction, reduced intestinal motility, conditions resulting in malabsorption, immune system conditions including IGA deficiency, deficiency of pancreatic enzymes, insufficient acid production of the stomach, and insufficient bile secretion.


Antibiotics and a low fat diet are often used to control the bacteria, and sometimes multivitamins are added as a supplement to make up for what is not absorbed from the food.  The change in the function of the small intestinal cells is usually reversible once the bacterial populations are once again in balance.  However, in cases of secondary SIBO, the primary condition causing the bacterial imbalance must first be treated before the secondary SIBO can be managed.

Links to sites about this disease:













This summary provided by:

bulletJessica S
bulletWildfire Kennel


Dedicated to improving the health of ISSR Shiloh Shepherds.


Copyright © 1998 - 2009. Shiloh Shepherd Dog™ Club of America.
All rights reserved. Revised: January 2008

The information on this website was written by ISSR breeders and other concerned individuals, however we are are NOT veterinarians. This information is being provided as a general overview, from information we were able to find about each disease through our own research. These summaries are not intended to be relied upon as medical or veterinary advice, nor do we consider ourselves experts in the veterinary field or in any of these conditions. While we do our best to provide the most up to date information, new research is constantly being done on these diseases. We recommend that you do further study and talk to your veterinarian on any topics you see here, as we cannot guarantee that the information posted here is the most current information available.  This site was originally designed and maintained by Debbie Knatz.