Magnesium for the treatment of ryegrass staggers

Authors: Allsop TF, Watters SJ
Publication: New Zealand Veterinary Journal, Volume 32, Issue 3, pp 39-40, Mar 1984
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant, Sheep
Subject Terms: Fungal/yeast, Locomotor, Minerals/elememts, Mycotoxicosis, Nervous system/neurology, Pasture/crop, Poisoning - plant, Disease/defect, Treatment/therapy, Toxicology
Article class: Correspondence

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Abstract: The use of orally administered magnesium salts to treat ryegrass staggers seems to have gained some popularity although the evidence for its efficacy appears to be largely anecdotal. In Australia the effects of acute annual ryegrass (Lolium rigidum) toxicity were ameliorated by subsequent intravenous or intramuscular injection of magnesium sulphate at 12-hourly intervals.  However, the risks associated with parenteral administration of strong solutions of magnesium salts make this an unsuitable method of treatment for ryegrass staggers. It is possible that an oral drench of a large amount of magnesium might have a pharmacological effect on the nervous signs of ryegrass staggers, even though the disease is not associated with decreased blood levels of magnesium. In February 1982, an outbreak of ryegrass staggers among calves and sheep at Wallaceville provided an opportunity to assess the effects of magnesium drenching on this disease under controlled conditions. Ten affected 6-month-old calves and 20 affected adult sheep were exercised and the severity of the nervous signs was scored using the scale of Keogh. The animals were then paired on the basis of these scores and one of each pair was drenched with a solution of 80% (w/v) magnesium chloride to give 10 g Mg/calf and 2 g Mg/sheep. Four hours later the animals (which had been left on the same pasture) were gain exercised and the clinical signs scored…

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