Grass staggers occurs due to magnesium deficiency. It occurs when the intake of magnesium is exceeded by its output. It is common in spring due to an increased requirement of magnesium for lactation and the decreased magnesium content of lush green pasture.


Magnesium has many important roles in the body and is involved in calcium metabolism. There are no reserves of magnesium in the body so normal functioning is dependent on dietary intake. Hypomagnesaemia occurs most commonly in adult cows which are lactating heavily and grazing on lush grass pastures. It can also occur in ewes in late pregnancy due to poor nutrition.

Grass staggers is not just restricted to the first few days of lactation. As with all metabolic conditions it is important to act fast. Contact Franklin Vets immediately if you notice the following symptoms

  • Hyper-excitability and restlessness
  • Unsteadiness and lack of coordination
  • Over-alert appearance

Response to treatment can be variable. Contact your veterinarian as soon as you suspect hypomagnesaemia. Magnesium solutions must only be administered under the skin. Many cases will require calcium treatment as well.