If your horse does not get enough of this nutrient in their diet, they may display some of the following signs. Horses that have a greater degree of deficiency and those engaged in more intense training display more serious symptoms. [8]
- Cribbing
- Stiff gait
- Muscle soreness
- Lethargy
- Diminished performance
- Muscle spasms, trembling or twitching
- Problems with chewing and swallowing
- Atrophy of muscle tissue
- Heart failure
Map of Selenium Deficient Soils in United States
Selenium concentrations in the soil vary widely in different parts of the world. The following map shows average soil levels in North America. The coastal and Northern areas have low concentrations while the Midwest generally has adequate levels in the soil.
However, even in regions with low concentrations of selenium, there may be pockets with high levels and vice versa. For this reason, it is best to have a hay analysis conducted to determine actual concentrations in your equine diet.
Regions considered low in this mineral are defined as those in which 80% of all forage and grain contain less than 0.10 ppm selenium. Medium regions have 50% forage containing greater than 0.10 ppm. Areas with adequate selenium are characterized as having 80% of all forages and grains with greater than 0.10 ppm.
