Vitamin B12/Folate

Serum vitamin B12 and folate concentrations are useful in diagnosing small intestinal malabsorption or “bacterial overgrowth” (now more commonly referred to as “antibiotic responsive diarrhea”) in dogs and cats. A single serum sample is required.

Low serum folate suggests malabsorption in the proximal small intestine.
Low vitamin B12 suggests malabsorption in the distal small intestine.
Low or normal vitamin B12 together with high folate suggests “bacterial overgrowth”.