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

Abstract

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&#x2009;day before and a median time of 1 and 60&#x2009;days after surgical treatment of CCLR. RESULTS: Median serum concentrations of total 25(OH)D before surgery (80.3&#x2009;nmoL/L [range, 43.5-137.3]) significantly declined immediately after surgery; (64.8&#x2009;nmoL/L [range, 36.3-116.5] 1&#x2009;day after surgery, P <&#x2009;.005) before increasing to become nonsignificantly different from concentrations before surgery at day 60 after surgery (median 78.0&#x2009;nmoL/L [range, 24.2-115.8], P =&#x2009;.14). In contrast, median free 25(OH)D concentrations before surgery (7.6&#x2009;pg/mL [range, 3.8-12.2]) significantly increased immediately after surgery (9.2&#x2009;pg/mL [range, 5.2-15.7], P <&#x2009;.05) before declining to become nonsignificantly different from before surgery concentrations at day 60 after surgery (median 6.2&#x2009;pg/mL [range, 4.0-15.8], P =&#x2009;.37). CONCLUSION AND CLINICAL IMPORTANCE: This study reveals the difficulties of assessing vitamin D status in dogs following elective surgery.