Trypsin-like immunoreactivity (TLI), cobalamin and folate are frequently measured in canine gastrointestinal disorders. However, the effects of preanalytical conditions on canine TLI, cobalamin and folate have not been clearly documented. This study evaluated the circadian variations of canine TLI, cobalamin, and folate concentrations in fasted and postprandial conditions.

Plasma TLI, cobalamin, and folate concentrations were measured after 12 hours of fast (Time 0), every 2 hours for 12 hours and at 24 hours in 8 healthy dogs. The same protocol was repeated after feeding after T0 samples. TLI, cobalamin and folate were measured by immunoassays validated in dogs (Siemens). Changes of TLI, cobalamin and folate were evaluated with a generalized linear model and Dunnett post hoc test.

Mean±SD circadian TLI concentrations in fasted dogs varied between 13.6±4.3 and 21.3±7.7 ng/mL and were significantly lower than T0 (p<0.01) at 2, 4, 6, 10, and 12 hours. In contrast TLI concentrations were not affected by feeding. Folate concentrations had no circadian variation in fasted dogs but were above the upper limit of quantification (24 ng/mL) in most time points after feeding. Mean fasted circadian cobalamin concentrations varied between 466±134 and 559±170 pmol/mL and were significantly different from T0 at 6, 8, 10, 12, and 24 hours (p<0.01). At 4, 6, 8, 10, and 12 hours post-feeding, cobalamin concentrations were significantly lower than at T0 (p<0.01).

Plasma TLI and cobalamin concentrations have significant circadian variations in fasted dogs. Plasma cobalamin is significantly decreased for 12 hours after feeding but plasma TLI remains unchanged.

Disclosures

Disclosures to report.
Benoit Rannou is an employee of the Laboratoire de Biologie Médicale, VetAgro Sup, University of Lyon, France where the sample TLI, cobalamin and folates measurements were performed.