Small Intestinal Bacterial Overgrowth

What is Small Intestine Bacterial Overgrowth?
Small Intestine Bacterial Overgrowth (SIBO) is an associated group of signs caused by an increase in number or type of microorganisms in the small intestine. Dogs with SIBO typically have chronic gastrointestinal problems such as diarrhea and flatulence.

How does my dog get Small Intestine Bacterial Overgrowth?
The small intestine is normally protected from excess bacteria by means of gastric acids, antibacterial mechanisms in the small intestine,  excretion, and a valve that prevents bacteria encroaching from the normally more highly bacteria populated large intestine. When these mechanisms fail---possibly because of partial blockages, decreased intestinal motility, intestinal parasites, or immune problems---the bacterial population in the small intestine grows to abnormal amounts or in abnormal ratios. This disrupts the normal absorption of the small intestine, causing diarrhea. The bacteria can also produce toxins that can affect the liver.

How do I know if my dog has Small Intestine Bacterial Overgrowth?
Affected dogs usually are in poor physical condition and have chronic diarrhea and loose stools, along with flatulence. Weight loss is common. Vomiting may or may not be associated. Your veterinarian will run specific blood tests that can help diagnose SIBO.  Other diseases such as exocrine pancreatic insufficiency and inflammatory bowel disease may have similar signs and occur concurrently, so  a more definitive diagnosis can be obtained through endoscopy, which requires your dog to be anesthetized. If this is not an option you're ready to pursue, your veterinarian may suggest a therapeutic trial, in other words treating your dog for SIBO and seeing if he improves.

What can I do about Small Intestine Bacterial Overgrowth?
Treatment consists of feeding your dog a veterinary  prescribed hypoallergenic or highly digestible diet that may contain fructo-oligosaccharides.  The veterinarian will also prescribe an antibiotic and possibly specific vitamins. Any underlying causes must also be corrected. Some dogs may improve in just days, whereas others may take two to three weeks.

Is there anything I can do to prevent my dog from getting Small Intestine Bacterial Overgrowth?
Aside from keeping your dog generally healthy and watching for other intestinal problems, there is nothing you can do to guard against SIBO.

Are there certain breeds that get Small Intestine Bacterial Overgrowth more often?
Chinese Shar-Pei and German Shepherds may be predisposed.