Small Intestinal Bacterial Overgrowth (SIBO) in Dogs

Small Intestinal Bacterial Overgrowth (SIBO) in Dogs

While it’s true that certain bacteria need to be present in the gut for digestion and absorption of nutrients to take place, if bacterial growth gets out of control, trouble ensues. That difficulty is called, quite simply, small intestinal tract bacterial overgrowth or SIBO. The disease can happen for a range of factors and it can affect any dog. Gas and diarrhea are the major symptoms. Antibiotics can assist quell bacteria overgrowth while underlying causes are dealt with appropriately.

Small Intestinal Bacterial Overgrowth (SIBO) in Dogs


The upper part of the small intestine is responsible for the continued digestion of food as it exits the stomach and for starting the procedure in which nutrients are absorbed into the blood stream for dissemination throughout the body. The bacteria present here typically aid in the procedure of breaking down partly digested food within the intestines. In dogs, the overgrowth of this bacteria leads to a typical process that’s descriptively labeled, “small digestive tract bacterial overgrowth” or SIBO.

It’s a huge issue for some dogs, and it takes place for several factors including the following:

  • Ileus: When normal peristaltic waves moving partially absorbed food forward aren’t present, bacterial populations increase. Neurologic issues, gastrointestinal obstruction, pancreatitis, peritonitis, parasitism, and other procedures can all cause the absence of forward digestive tract motion called ileus.
  • Modified Digestion or Absorption of Nutrients: This can occur with exocrine pancreatic deficiency (insufficient secretion of digestion enzymes by the pancreas) and other disorders that can cause bad food digestion and absorption of nutrients.
  • Malnutrition or immunodeficiency: When the body’s total condition is negatively impacted, all the normal defenses can break down, resulting in uncontrolled bacteria development.

The above have the tendency to be identified secondary causes of SIBO. However SIBO can likewise be idiopathic, which means vets do not comprehend precisely why it occurs.

Symptoms and Identification

Secondary SIBO can impact any dog, depending on the underlying cause. But idiopathic SIBO tends to affect reasonably young dogs. Diarrhea and flatulence (gas) are the most common signs of SIBO. Chronic, intermittent diarrhea is most common, with many dogs also suffering weight reduction, stunted development, and/or generalized failure to grow or gain weight. Some dogs might appear extraordinarily starving and might even eat their stools or other indigestible items.

SIBO is identified by noting small bowel diarrhea (identified by restricted straining and big volumes) and finding large numbers of bacteria in the fecal product. Medical diagnosis is aimed primarily at eliminating other potential causes of bacterial overgrowth and diarrhea. Since these countless, the process usually involves X-rays, serial fecal examination (not cultures, which are infamously unreliable), and in some cases endoscopy to test the upper part of the small intestine for high bacteria counts.

Blood tests that expose high folate levels and decreased cobalamine might likewise be indicative of the process. That’s because folate is synthesized by the bacteria, and cobalamine is bound by them. Nevertheless, these tests might be inconclusive.

Affected Breeds

German Shepherds are over-represented among those who suffer with SIBO, however dogs of any breed can be impacted.


Treating the underlying process is the technique best undertaken for secondary SIBO. For idiopathic SIBO, antibiotics are extremely efficient in assisting owners handle their dogs’ medical signs. That’s why this variation of the disease is often referred to as antibiotic-responsive SIBO or antibiotic-responsive diarrhea (ARD).


For secondary SIBO, if the underlying cause can be resolved, the condition is more easily corrected. However, there is no treatment for idiopathic SIBO. Some young dogs may appear to grow out of the condition (perhaps as their immune system develops), but in other cases dietary therapy and supplements might be suggested to help manage the condition long term.

Also read: Stomach and Intestinal Ulcers in Dogs

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References and used sources

D. Roberts (Junior Expert)

He is a specialist in the field of veterinary medicine, and pet care. Believes that the person responsible for each pet, which was taken into the house, and therefore should study his behavior, means of determining health status and methods of first aid.

Pet Health
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