There have already been a few cases of sleepy sickness and milk fever occurring and the inevitable queries on how to tell them apart and what to treat them with. The essential features of each condition are as follows:
Sleepy Sickness (Pregnancy Toxaemia): The energy demand on a ewe carrying multiple lambs over the last 6 weeks, in particular, the last 4 weeks before lambing, are huge. If, through under nutrition, she cannot eat enough feed to provide that energy she utilises body fat as a source of energy – this can be more pronounced in fat ewes. A by product of this process is the production of ketones which are toxic. Mild underfeeding in the last 2 - 3 weeks pre-lamb can, even in the absence of obvious symptoms of sleepy sickness, produce enough ketones to depress newborn lamb survival.
More extreme cases of underfeeding result in the classical signs of sleepy sickness progressing as follows:
Treatment: This needs to be given early in the course of the symptoms to have any chance of success. Due to brain damage, it is hopeless once the ewe is down and stopped eating. Give energy in the form of 160ml Ewelife orally. Either repeat this a few hours later, or follow up with Ketol or Ketovet. Other products farmers have used with some success are Headstart and Ewe Reviver. Put on good feed.
Milk Fever (Hypocalcaemia): Occurs mainly in good condition ewes before lambing, but can occur up to a month after lambing and often occurs within 24 hours of a sudden feed check, as after changes in feed, sudden storm or short periods of fasting following yarding.
It is more sudden in onset than sleepy sickness and likely to involve greater numbers initially.
Treatment: 120 – 150mls Glucalphos, Calpromag (or similar products containing 25% Calcium borogluconate, and preferably, some magnesium & dextrose. Some of these products now contain Vit B12 which may help as well. Give under the skin over the ribs in at least two sites and massage in well. The response to treatment is usually rapid (within 30 mins) unless it is complicated by sleepy sickness as well, so treatment can be used as an aid to diagnosis.
It is possible to have both conditions occur together. If this is the case or you are not sure, treat for both bearing in mind you are not going to have a great success rate once ewes with sleepy sickness are down.
Written by John Smart BVSc
Extract from September 2008 - Sheep Newsletter
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