Ewe metabolic disease
Sleepy sickness and milk fever are metabolic diseases seen in sheep, most often affecting in-lamb ewes in the last few weeks before lambing.
Sudden changes in feed, either feed type or grazing regime, will cause a check in feeding which can lead to either of the above problems. Holding for crutching or shearing heavily pregnant ewes, inclement weather, excessive droving, or diseases reducing intake can also trigger outbreaks.
Ewes with milk fever (being a drop in blood calcium called hypocalcaemia) will initially be staggery, then go down and progress to an apparently comatosed state. Those left untreated will go into a deep coma after 24 hours and die. The response to treatment for milk fever is usually rapid (within half an hour) unless complicated by sleepy sickness.
Sleepy sickness, also known as twin lamb disease, is due to ketosis when there is excessive fat breakdown. It most often occurs in late pregnant ewes carrying multiple lambs. Clinical signs are similar to milk fever but are usually slower to progress. Initially affected ewes lag behind the rest of the mob and appear depressed and/or blind (the classic ‘star gazing' position). Later ewes become staggery, twitchy around the ears, eyes and muzzle, and froth at the mouth. Eventually ewes will become comatose and, generally after several days, will die.
The response to treatment for sleepy sickness is variable and often disappointing. Sheep with the characteristic ‘razorback' and wool pull are very unlikely to respond to therapy. If the ewe is still eating, the prognosis is more favourable, but if she is down and has stopped eating the prognosis is grave.
Milk fever and sleepy sickness can be really hard to tell apart, and ewes will often have both so we tend to treat them the same! It is also important to note that lambs born from recovered ewes are commonly stillborn (sleepy sickness), or have poor survival rates (milk fever).
If you have any questions, or would like further information, please don't hesitate to give the us a call.