Over the past week there has been a sharp increase in the amount of grass tetany cases diagnosed and in the Riverina region.

Grass tetany is a metabolic disease that affects cattle and sheep, associated with low levels of magnesium in the blood.

Grass tetany is a complex disorder, but the most common causes around this time of year are cattle under environmental stressors, lactation and mustering. In addition to this, animals rapidly growing on short young grass or lush cereals are most affected.

Often the only signs most farmers note with grass tetany is sudden death. There is usually frothing from the mouth and nose, and there are usually signs of where the animal has moved violently prior to death.

Cows may show signs when disturbed or yarded. These are often displayed as nervous signs: arching of the head back, muscle spasms, convulsions, walking stiffly or galloping madly and going down and unable to get up again.

Treatment focuses on returning magnesium levels back to normal by injecting solutions containing magnesium into the affected animals. 

Prevention of grass tetany focuses on providing animal’s easy access to supplements, such as hay treated with Causmag on an ad lib basis.

The daily requirement of Causmag for cattle is 60g/head/day but up to 100g/head/day may be necessary in some instances. After a feeding regime has begun, it takes 2-3 days for stock to be protected, with protection ceasing once supplementation has ceased.

If you suspect grass tetany is affecting your herd, contact your local vet or nearest Riverina Local Land Services District Veterinarian for further information and advice.