Sheep producers with pregnant ewes have been warning that cases of hypocalcaemia, or milk fever, a deficiency of calcium in the blood, were expected at this time of year.
Hypocalcaemia might be prevented by adding a calcium supplement, or by giving dry roughage to sheep on lush feed," according to Agriculture Victoria.
Milk fever usually occured in mature, fat ewes during the last six weeks of pregnancy or the first 10 days after lambing, although other classes of sheep may also be affected.
Hypocalcaemia often followed time off feed or stressful events such as shearing, crutching, transport, mustering, yarding. Cases of hypocalcaemia could also occur during exposure to inclement weather.
Hypocalcaemia usually occured in sheep on either rapidly growing pasture, green cereal crops, when feeding grain, or on pasture that had oxalate containing plants such as sorrel and soursob.
Cases of hypocalcaemia were often weak or down ewes and could be confused with pregnancy toxaemia (twin lamb disease).
The notable differences between the two conditions was that hypocalcaemia had rapid onset, that affected sheep remained alert and there was a good response to appropriate treatment.
Sheep affected with hypocalcaemia should be treated as a matter of urgency with calcium solution, often known as 4-in-1, given under the skin. Calcium solution was available from veterinary practices or rural merchandisers.