Effects of surgery on free and total 25 hydroxyvitamin D concentrations in dogs

BACKGROUND: It is unclear whether a low total 25(OH)D concentration is a cause or consequence of illnesses. To address this knowledge gap, studies measuring free and total 25(OH)D during the evolution and resolution of an inflammatory process are required.OBJECTIVES: Serum total and free 25(OH)D concentrations would transiently decline after cruciate surgery in dogs.ANIMALS: Seventeen client-owned dogs with a spontaneous cranial cruciate ligament rupture (CCLR).METHODS: A longitudinal cohort study involving the measurement of serum concentrations of total and free 25(OH)D, total calcium, creatinine, albumin, phosphate, C-reactive protein and plasma ionized calcium, at 1 day before and a median time of 1 and 60 days after surgical treatment of CCLR.RESULTS: Median serum concentrations of total 25(OH)D before surgery (80.3 nmoL/L [range, 43.5-137.3]) significantly declined immediately after surgery; (64.8 nmoL/L [range, 36.3-116.5] 1 day after surgery, P CONCLUSION AND CLINICAL IMPORTANCE: This study reveals the difficulties of assessing vitamin D status in dogs following elective surgery.