Analysis of serum magnesium ions in dogs exposed to external stress: A pilot study

Magnesium ions (Mg(2+)) are essential for various enzymatic reactions in the body associated with energy production and activation of the muscles and nerves. Mg(2+) is also involved in blood pressure regulation, maintenance of body temperature, and glucose metabolism. Although various factors including foods and physical conditions have been reported to change serum Mg(2+) status in humans, serum Mg(2+) in dogs exposed to external stress has been unclear. In this study, we examined serum levels of Mg(2+) in dogs at different conditions using the guide dog candidates for the blind. Serum Mg(2+) was decreased in winter and increased in summer. Guide dog candidates in an elementary class of the training showed markedly lower levels of serum Mg(2+), compared with that of dogs in an advanced class. When healthy adult dogs were subjected to forced exercise using a treadmill, a significant reduction in serum Mg(2+) levels was observed, particularly in winter. These findings suggest that serum levels of Mg(2+) may be influenced by weather fluctuation such as air temperature, nervousness in unaccustomed situations, age, and physical stress induced by exercise. The results indicate that Mg(2+) supplementation should be considered for working dogs, dogs moving or traveling to a new environment, and dogs during winter.