Grass tetany

Weidetetanie also called pasture fever is a disease in ruminants, which results from a magnesium deficiency of the organism. Magnesium is required in the muscle, to provide the cyclic relaxation of the muscles. In magnesium deficiency leads to muscle spasms.

Causes and Occurrences

Grass tetany can be caused by too little magnesium in the diet occur (primary magnesium deficiency), but in addition also, if the inclusion of magnesium is reduced from the feed (secondary magnesium deficiency). A secondary magnesium deficiency occurs especially when the potassium content of the diet is far too high (for example, instead of 1 % more than 3% of dry matter). Magnesium absorption takes place in ruminants almost exclusively in the rumen. For the recording of Mg from the interior in the Pansenepithelzelle there is a potential dependent transport (presumably through an ion channel) and a potential- independent, which presumably proceeds via a cotransport with chloride ions. The levy on the Mg from the rumen to the blood occurs by a Na -Mg - exchanger.

Grass tetany occurs mainly at pasture buoyancy of the animals as young grass in the potassium content is much higher than in older. In addition, particularly cold spells in spring mean by their effects on the growth of young grass, and thus on its potassium content a danger. Typical clinical picture is the so-called " downer " animals, meaning they are no longer to be in the situation and are (depending on Schwere-/Mangelgrad ) in breast or side position on the ground.

Due to the relatively balanced feed rations in cattle farming, the disease now plays in dairy cattle a completely subordinate role or is of other metabolic disorders ( milk fever, displaced abomasum, etc.) have been displaced.

Clinical picture

A clinically manifest Weidetetanie shows up in spasms that usually start with ears flapping and vigorous wink and later shows with stiff, intersecting hind legs. Occur frequently twitching muscles of the limbs and an elongated head by spasms of the neck muscles. There is often strong excitation that can go up to running against obstacles and increased aggressiveness. Within minutes to hours it comes to recumbency with head stretched back and flailing legs, and apathy. Each external stimulus can trigger renewed seizures. Finally, the animals are drowsy or even fall into a coma. Typical are heart palpitations and severe dyspnea. Death occurs without treatment by cardiovascular failure.

Treatment

The success of treatment properly on how quickly therapy is initiated. Already kicking convulsions, is not expected to self-healing, with timely veterinary intervention can save 70 % of the animals. Initial treatment is by administering Mg -containing infusions under constant control of heart rate. Subsequently, the oral administration of magnesium oxide is possible.

Prophylaxis

• Mg administration: Supplementary feeding a magnesium- rich mineral feed Before to pasture.
• Beifüttern no abrupt diet change from winter to summer ration or feed structure.
• Improvement of Mg absorption: feeding of NaCl, increase fiber content of the ration, omission extreme K- and N- fertilization
• Avoiding stress