Be on the watch out for twin lamb disease

It’s been a tough couple of days for sheep farmers; especially those whose flocks were exposed to the elements. With this in mind, farmers need to watch out for twin lamb disease (pregnancy toxemia).

The most common cause of this metabolic disease is inadequate feeding in late pregnancy – a critical period for foetal development.

During the final six weeks of gestation alone, 75% of total foetal growth occurs. Failing to meet the ewes’ dietary needs for energy can result in cases of twin lamb disease occurring. It must also be noted that ewes carrying multiples are most at risk.

It occurs predominately in the period right before lambing when the lambs are growing at their most rapid levels in the uterus.

However, stress also has a role to play in the onset of the disease and housing can trigger its onset.  In addition, last’s weeks snow may also have placed ewes under stress. Given this, farmers need to be vigilant of the symptoms.

The symptoms

When the ewe’s energy requirements are not met, she begins to mobilise fat reserves. This leads to the production of ketones, which impair the ewe’s normal bodily functions.

An affected ewe can be easily identified, as she isolates herself, looks dull, will not eat, appears blind and lies down. In many cases, the ewe’s breath will also be sweet smelling.

If the condition is untreated, it results in death.


The response to treatment is usually poor and mortality can be as high as 90%. However, ewes suffering with the disease will require glucose treatment as soon as they go off food.

This provides the best chance of survival for both the ewe and the lambs. The oral administration of glycerol or propylene glycol is also warranted. The induction of labour may also be considered, as this immediately reduces the ewe’s energy requirement for foetal growth.