2015 ACVIM Forum Research Abstract Program

Surplus fecal samples from 21 dogs enrolled in an unrelated clinical trial at the Gastrointestinal Laboratory were utilized. To be included into the study, the dogs had to be at least 1 year of age, have clinical signs of EPI (i.e., polyphagia, weight loss, steatorrhea, and/or loose, voluminous and/or malodorous stools), have a serum cTLI concentration ≤2.5 lg/L, not be pregnant or lactating, and be free from any clinically apparent disease other than EPI. Three naturally voided fecal samples collected over three consecutive days were immediately frozen after collection and were used for the study. Fecal N-methylhistamine concentrations were measured using a previously validated in-house assay using stable isotope dilution gas chromatography/mass spectrometry (GC-MS). A liquid extract of each fecal sample (1:5 dilution) was used for NMH analysis and fecal NMH concentrations were back-calculated for the wet weight of the fecal samples and expressed in ng/g feces. Results were compared with the established reference interval for healthy dogs and a mean three-day fecal NMH >191 ng/g feces or a maximum fecal NMH of one individual sample of >334 ng/g feces was considered abnormal.