Prevent pregnancy toxaemia this season

With many local flocks already lambing and others about to start, district vets with the Riverina Livestock Health and Pest Authority are reminding producers about the prevention of pregnancy toxaemia in sheep.

Gabe Morrice, Riverina LHPA district vet, says early cases of pregnancy toxaemia have been reported around Barellan and further west, serving as a timely reminder to local producers to initiate strategies to prevent the condition.

"The main cause of pregnancy toxaemia is inadequate nutritional energy intake in the last trimester of pregnancy. This is usually due to decreased rumen capacity as a result of the growth of the foetuses, low energy value of the feed, and a higher energy requirement of the ewe carrying multiple lambs in the last few weeks of pregnancy," said Dr Morrice.

"However it can be compounded by any other problem which causes a ewe to reduce her intake of food in late pregnancy. Examples of this include foot abscess, handling for shearing, crutching or drenching and inclement weather conditions."

Dr Morrice said to look out for the tell-tale signs of pregnancy toxaemia – lethargy, separating off from the mob, not eating and drinking, progressing to blindness, incoordination, then recumbency, coma and inevitably death.

"The disease is often confused with hypocalcaemia (low blood calcium) which can also occur in late pregnancy or early lactation in ewes. The treatment and prevention of these two diseases differs, so it is important to have them correctly diagnosed," Dr Morrice said.

"Treatment needs to be given as soon as possible for the best chance of success. Treatment in advanced cases is often unrewarding and it is important to see the first few cases as a reminder to put preventative measures in place to avoid further new cases.

"Preventive measures are aimed at increasing the nutritional energy levels of the feed being supplied to affected sheep. This is usually done by a staged introduction of grain feeding, from approximately 6 weeks before lambing. Ideally, ewes should not reach the last trimester of pregnancy in greater than a body condition score of 2.5.

"Avoid yarding late pregnant sheep unless vital and in particular avoid holding them in yards overnight.
If other stress factors are present (e.g., foot abscess) try to implement treatment measures as early as possible to avoid prolonged periods of reduced feed intake."

For more information on the management of pregnancy toxaemia and other metabolic diseases of livestock contact your local LHPA district vet.

Media contact: Kylie Dunn 6391 3720 / 0428 465 378