The occurrence of grass tetany in cattle and sometimes sheep is influenced by many things. Among these factors are soil temperate, condition of the animal, magnesium content of the feed, lactation phase of the animal, and other related items. Magnesium is a critically important component of the blood required to ensure a healthy animal. When the magnesium level becomes too low, the animal becomes excitable, wild, falling, paddling and may die. The time lapse between onset and treatment is extremely important if the animal is to survive.
Cool weather interferes with the forage uptake of magnesium from the soil.
When the animal consumes large amounts of the forage, it will likely become affected. Cows that are nursing calves become unprotected from grass tetany, as milk production assists in further depleting the system of this element. Grass tetany develops quickly and is more severe when the animals are moved or undergo stressful conditions. Affected animals require immediate attention. This usually involves an intravenous injection of a magnesium and calcium solution.