If a cat is experiencing signs of gastrointestinal distress, a veterinarian should be consulted. There are many possible causes and proper diagnosis is needed to determine the correct course of action. With the right treatment, prognosis for SIBO is excellent and the condition usually clears up within a few days to a few weeks.

The upper part of the small intestine is responsible for food digestion. A certain number of bacteria must be present in the intestines in order for the system to function properly. When the bacteria feeds on undigested food material, it begins to thrive and can multiply to problematic levels. This condition, known as small intestinal bacterial overgrowth (SIBO), causes loose stools and rapid weight loss. If left untreated, toxins caused by excess bacteria can severely damage intestinal cells, causing permanent digestive disorders and food intolerances. 

Cats with excessive bacteria in the small intestine are likely to experience one or more of the following symptoms:

There are several possible causes the accumulation of excess bacteria in the small intestine of cats: 

In some cases, the cause of SIBO cannot be determined. This condition is also known as idiopathic antibiotic-resistant diarrhea. It is more common in younger cats and often resolves itself as the animal ages, presumably due to the development of the immune system.

Symptoms of SIBO are similar to those caused by a variety of other conditions, making it difficult to reach a definitive diagnosis. The veterinarian will want to review the cat’s full medical history and discuss its current diet. It will be helpful if you are able to provide a detailed description of the specific symptoms and any past problems. A complete physical exam will be completed and blood work will often be ordered to rule out other potential causes. A series of fecal tests will often be necessary. If the vet feels that he or she need visual aids, an x-ray or ultrasound may be ordered. An endoscopy is typically only used in extreme cases as the procedure is highly invasive and requires anesthesia.

Hospitalization is not typically required for treatment of SIBO. In the absence of a more severe underlying cause, a fast and full recovery is expected.

The first line of treatment is usually a prescription for antibiotics or antimicrobials to control the growth of bacteria in the small intestine. Symptoms typically subside within a week, but treatment may be continued for several weeks to ensure that bacterial growth has slowed to normal levels. With long-term or chronic antibiotic use, there is a concern regarding the development of antibiotic resistance or the possibility of liver damage. Owners may wish to discuss this with their veterinarian.

Probiotics such as acidophilus and lactobacillus and prebiotics like fructo-oligosaccharides (FOS) are often recommended to encourage the growth of beneficial bacteria to help restore normal function in the small intestine. If the cat is suffering from long bouts of diarrhea, dehydration and electrolyte imbalance are serious concerns. Vets and owners will need to closely monitor affected cats and additional medication may be administered to treat the condition.

Your veterinarian is likely to recommend that you make changes to your cat’s diet to aid in healing. Foods that are highly digestible and low in fiber tend to work best for affected cats. Owners should closely follow veterinarian recommendations and changes should not be made without prior consultation.

If it is determined that SIBO is caused by a pancreatic inefficiency, enzyme replacements should be added to the food. This is often necessary for the remainder of the animal’s life. Vitamin supplements are often necessary to correct deficiencies that may develop as a result of pancreatic conditions. Vitamin K plays an important role in blood clotting and a shortage can cause bleeding problems. Vitamin B12 deficiency must also be corrected in order for animals to properly respond to treatment and survive. Owners should always consult a veterinarian before administering supplements or any other medications.

Regular veterinary check-ups will be needed to ensure proper recovery. Protein and B12 levels should be regularly monitored and the cat’s behavior should be observed closely. Owners and vets should both weigh the cat regularly and take steps to ensure that it remains hydrated and properly nourished.