Validation of the bovine blood calcium checker as a rapid and simple measuring tool for the ionized calcium concentration in cattle

Abstract

Hypocalcemia is a metabolic disorder in which homeostatic mechanisms fail to maintain normal blood Ca concentrations at the onset of lactation. Although the incidence of clinical milk fever in the United States is approximately 5%, as many as 50% of periparturient dairy cows may have subclinical hypocalcemia, with total blood Ca concentrations being between 1.38 and 2.0 mM. As intravenous 22.5% calcium borogluconate infusion immediately induces a state of hypercalcemia, followed by reduction of the whole blood ionized calcium (iCa) and serum total calcium (tCa) concentrations 24 hr later. Therefore, it is difficult to maintain an ideal blood calcium level without monitoring the blood calcium level. Point-of-care (POC) devices that veterinary practitioners can use to easily and rapidly measure blood ionized calcium (iCa) levels in cows immediately after withdrawing a blood sample on the dairy farm are needed. Aims of present studies was to compare the commercially available ion-selective electrode handheld iCa meter (bovine blood iCa checker) with the benchtop blood gas analyzer GEM premier 3500 and handheld analyzer i-STAT 1.