Comparison of Direct and Indirect Tests for Small Intestinal Bacterial Overgrowth and Antibiotic-Responsive Diarrhea in Dogs

Abstract

Controversy exists over the diagnosis of idiopathic small intestinal bacterial overgrowth (SIBO) in dogs and some clinicians use the term antibiotic-responsive diarrhea (ARD) in preference. However, whether such terms are interchangeable is not clear. To examine the relationship between duodenal bacterial numbers and a clinical response to antibiotics, SIBO and ARD were defined by nonoverlapping criteria. Quantitative duodenal juice bacteriology and indirect serum biochemical tests were used to assess small intestinal bacterial populations in 30 dogs with gastrointestinal disorders, including 9 with ARD. Serum total unconjugated bile acid (TUBA) concentrations were measured in all dogs, serum folate and cobalamin concentrations were measured in 29 of 30 dogs, and quantitative culture of duodenal juice was performed in 22 of 30 dogs. Serum TUBA concentrations also were measured in samples from 38 control dogs. Twenty of 22 affected (clinical) dogs in which quantitative bacteriology was performed were classified as having SIBO (Ͼ10 5 colony-forming units of total bacteria per milliliter of duodenal juice), but bacterial numbers did not differ significantly between dogs with ARD and dogs with other disorders. Increased folate (19/29), decreased cobalamin (16/ 29), or a combination (9/29) were common, but increased TUBA concentrations were documented in only 5 of 30 clinical dogs. Again, no significant differences were observed between dogs with ARD and those with other disorders, and a similar proportion (5/38) of controls had abnormally high TUBA concentrations. Finally, no significant differences were noted when duodenal bacteriology and TUBA concentrations were assessed before and during antibiotic therapy. These results question the utility of quantitative duodenal juice bacteriology and indirect biochemical marker tests for SIBO in the investigation of canine gastrointestinal disorders.

A Case of Protein-Losing Enteropathy Treated with Methotroexate in Dog

“…A report of IBD in a dog has suggested a tendency toward cobalamin deficiency [7]. In the present case, the serum cobalamin concentration before MTX administration was low at 97 pg/ml (lower limit of normal range=215 pg/ml [7]). However, cobalamin levels improved in response to 6 weeks of MTX with cobalamin supplementation.…”

Intestinal Microbiota of Dogs and Cats: a Bigger World than We Thought

“…Cultivation results Much of the published data describing the composition of the gastrointestinal microbial ecosystem in dogs and cats has been generated using bacterial cultivation techniques. [26][27][28][29][30] These studies have revealed that total bacterial counts in the stomach range between 10 1 and 10 6 cfu/g or ml. 26 The bacterial load in the duodenum and jejunum of dogs and cats shows pronounced individual variations.…”

“…Duodenal bacterial counts are low in most dogs (<10 3 cfu/g or ml of duodenal aspirates), but they may reach up 10 9 cfu/g or ml in some dogs. 29,30 The feline duodenum reportedly harbors higher bacterial counts (10 5 -10 8 cfu/g or ml), and anaerobic bacteria (Bacteroides spp, Fusobacterium spp, Eubacterium spp) appear to predominate unlike in dogs. 29 The bacterial counts found in the proximal small intestine of some healthy dogs and cats are substantially higher than typically found in humans, where bacterial counts greater than 10 5 cfu/g or ml of small bowel aspirates indicate small intestinal bacterial overgrowth (SIBO).…”

A Retrospective Study in 21 Shiba Dogs with Chronic Enteropathy

“…Although the pathogenesis of the disease has not been completely clarified yet, some reports in human medicine and laboratory animals have demonstrated underlying genetic factors related to the disease [5]. In veterinary medicine, some breeds are known to be predisposed to specific types of chronic enteropathy, such as protein-losing enteropathy and nephropathy in the Soft Coated Wheaten Terrier [18], immunoproliferative enteropathy in the Basenji [3] and chronic enteropathy and ARD in the German Shepherd [2,11]. The existence of so-called breed-specific chronic enteropathy implies that some kinds of genetic factors are associated with the pathogenesis of the disease in dogs.…”