Twin lamb disease
During the last six weeks of a ewe’s pregnancy there are huge energy demands placed on her – her lambs are growing extremely fast and she has to start producing protein-rich colostrum (first milk). Add to this a lack of space in her abdomen due to large lambs pressing on her stomachs, it can be difficult for the ewe to physically eat enough food to meet her energy requirements at this time.
Twin lamb disease is caused by this negative energy balance and can be fatal if not treated promptly. It gets its name as it is mostly seen in ewes carrying multiple lambs and usually in older, thin ewes. Commonly a stressful event such as housing, inclement weather conditions or handling can trigger the disease in at-risk ewes.
Spotting twin lamb disease
Often in the early stages of twin lamb disease the ewe will isolate herself and appear lethargic. As the condition progresses the ewe may show muscle tremors, she may appear blind (disorientated, bumping into things) and she will become unable to rise and stop eating.
How to treat the disease
Treatment needs to be administered ASAP to save the ewe and her lambs. The sick ewe should be penned on her own and offered plenty of palatable roughage, concentrates and a constant supply of clean, fresh water. In order to restore her energy levels, oral energy solutions should be administered. Propylene glycol is a good choice of energy drench and 100ml should be given by mouth on day 1 of the disease and 50 ml on day 2 and day 3.
Twin lamb disease can be very difficult to distinguish from hypocalcaemia, which is a calcium deficiency in late pregnancy. Therefore it is advisable to administer 80ml of calcium injection under the skin at the same time. If in any doubt or if the ewe does not improve or deteriorates during treatment, veterinary assistance should be sought. Ewes with twin lamb disease need to be closely monitored for any signs of lambing or abortion as they may be too weak to lamb by themselves.
In some instances where the ewe isn’t responding to medical treatment, the vet may induce her to lamb or even consider a caesarean section. The reason for this is that once the ewe has lambed the energy demands placed on her will drop and she will be able to recover.
Prevention is better than cure
Having ewes in an appropriate body condition score during pregnancy will provide them with a good energy reserve to help prevent twin lamb disease. For lowland flocks the target body condition score during pregnancy is 3 out of 5 (a good resource on body condition scoring ewes can be found online in the AHDB manual ‘Managing ewes for better returns’).
Because of this lack of room in the abdomen for ewes carrying multiple lambs, concentrate feeds need to be fed to meet the energy demand. The exact energy requirement will depend on how many lambs the ewe is carrying, therefore pregnancy scanning can be a useful tool to find this out and feed accordingly.
Chat to your vet to make a nutrition plan for lambing and remember minimising stress in late pregnancy is critical in preventing twin lamb disease and other complications.
Down ewes should be bedded on deep straw and offered fresh water and feed
is key Managing nutrition lamb to preventing twin flock disease in your