by: Dr. G.F. Kennedy
Bloat is simply an over distention of the rumen by gas. It can occur as either free gas bloat or as frothy bloat. Frothy Bloat generally occurs when sheep are grazed on lush legume pasture such as alfalfa or clover. These plants produce a substance that will cause foaming in the rumen and the animal is unable to eructate or relieve their gas. Bloat is diagnosed when there is severe distention of the abdomen on the left side behind the last rib. To relieve free gas bloat you can either pass a stomach tube into the rumen or stick a 16 gauge by 1 ½ inch needle into the rumen behind the last rib. To treat frothy bloat you need to administer 50ml of vegetable oil orally or injected into the rumen. This will break up the foam and allow the animal to eructate. Commercial anti-foaming agents such as Therabloat are more effective.
Grass Tetany occurs when sheep are grazing lush on heavily fertilized pasture. Fast growing plants have low levels of magnesium and since ruminants store very little magnesium they become deficient. Affected sheep will show a stiff gait, abnormal coordination, convulsions when stimulated, and may be found dead. Successful treatment for Grass Tetany is to administer subcutaneously 50-100 ml of a magnesium containing solution such as calcium boroglucanate (CMPK) Magnesium enemas are also rapidly absorbed and successful. Feeding magnesium in mineral free choice mineral mixes for 30 days prior to pasture turnout is helpful, as is allowing sheep to fill up on dry hay immediately prior to pasture turnout. Limiting grazing for the first few days is also beneficial. Up to 20% of the affected animals may die even with therapy. Grass Tetany is most prevalent in the Southern United States.