Hypomagnesemia in Sheep
Magnesium deficiency and sudden death in Sheep
Capacity building - LEP 23-021-18
The issue
Hypomagnesaemia, or grass tetany, is a health problem that can affect sheep, especially in the first few weeks after lambing. It happens when there’s not enough magnesium in their blood, which can make them sick or even cause sudden death. Sheep can’t store magnesium in their bodies, so they need to get a steady supply from their feed. They’re most at risk in times when grass is growing quickly, like in spring, because that’s when the magnesium in the pasture can be low.
The solution
Prompt treatment is essential for it to work. It’s best to inject a combined calcium and magnesium solution (about 100ml for sheep) under the skin, just behind the shoulder and over the rib area. Give the spot a good massage after injecting to help spread the fluid and get it absorbed quickly into the bloodstream.
The impact
Sheep with grass staggers (hypomagnesaemia) often show signs like shaking, especially around the face, and may have trouble walking or move with stiff legs. Sometimes they go down and have severe muscle spasms, where all four legs stick out straight. Unfortunately, they can die very quickly — sometimes before you even notice any other signs. To be sure, you can get a blood test done, which will show low magnesium levels.