Grass tetany

Grass tetany, also known as hypomagnesemia, is a critical metabolic disorder affecting primarily ruminants, such as cattle, sheep, and goats. It is characterized by low levels of magnesium in the blood, leading to neurological and muscular symptoms. Grass tetany is most commonly observed in grazing animals during the spring when they are feeding on rapidly growing, lush pasture grasses that are low in magnesium. This condition can be fatal if not promptly diagnosed and treated.

Causes

Grass tetany is primarily caused by a deficiency of magnesium (Mg) in the diet. Magnesium is essential for many bodily functions, including nerve transmission and muscle contraction. Factors contributing to the development of grass tetany include:

• Consumption of pastures with low magnesium levels, often due to rapid grass growth in the spring or after fertilization with high levels of nitrogen and potassium.
• Poor absorption of magnesium from the rumen, which can be exacerbated by diets high in potassium or nitrogen, as these elements interfere with magnesium absorption.
• Increased magnesium demand, such as during lactation, when animals are under stress, or in conditions of high humidity and cold weather.

Symptoms

Symptoms of grass tetany can vary from mild to severe and may include:

• Nervousness and hyperexcitability
• Muscle tremors and spasms
• Incoordination and difficulty walking
• Collapsing
• Convulsions
• Coma
• Death

Early detection and treatment are crucial for the recovery of affected animals.

Prevention

Preventative measures for grass tetany focus on ensuring adequate magnesium intake. Strategies include:

• Supplementing diets with magnesium, either through mineral blocks, licks, or by adding magnesium oxide to feed.
• Avoiding the use of high nitrogen and potassium fertilizers on pastures where susceptible animals graze.
• Providing access to older, more mature pastures that have higher magnesium content.
• Monitoring and managing the condition of animals, especially those at higher risk such as lactating females.

Treatment

Treatment for grass tetany involves the administration of magnesium, usually in the form of an intravenous solution of magnesium sulfate, by a veterinarian. This treatment can rapidly reverse the symptoms of magnesium deficiency if administered promptly. In severe cases, additional supportive treatments may be necessary.

See Also

• Ruminant nutrition
• Metabolic disorders in animals
• Hypocalcemia

References

This veterinary-related article is a stub. You can help WikiMD by expanding it.