According to the literature, 28% of cats in intensive care units are low in magnesium based on total serum magnesium concentrations. Cats with low magnesium concentrations are hospitalized longer than cats with normal concentrations. However, in cats, total serum magnesium is a less sensitive measure of magnesium status compared to ionized magnesium concentrations. Less than 15% of cats with low magnesium concentrations, based on ionized magnesium analysis, were detected when evaluated using total magnesium. Currently, there is no clear recommendation concerning the most sensitive measure of magnesium status in cats. It is likely that many patients with low magnesium are not identified if they are evaluated using total magnesium analysis. Furthermore, although most patient’s nutritional support include some magnesium, it may not be enough to correct their deficits. Low magnesium levels may also occur, or worsen during the refeeding process. This study will provide clinically relevant information concerning magnesium metabolism in cats by accomplishing the following objectives:
1. Establishing reference intervals for ionized and total magnesium concentrations,
2. Determining the prevalence of low magnesium levels in anorexic cats,
3. Determining the effect of nutritional support on magnesium status, and
4. Determining outcomes (including illness and death rates) in patients with low magnesium levels that receive magnesium supplementation versus those managed traditionally.
This study will provide recommendations concerning the most sensitive indicator of magnesium stores, and the impact of anorexia and re-feeding on magnesium status, as well as the potential benefits of magnesium supplementation in cats.