Feedback
Lambing sickness and milk fever in ewes
Lambing sickness (pregnancy toxaemia or twin lamb disease) and milk fever (hypocalcaemia) are 2 metabolic diseases affecting ewes in the late stages of pregnancy.
Lambing sickness is the most common of the 2 diseases. In severe cases, it can cause a high loss of ewes and lambs.
These diseases initially appear similar: they can be triggered by similar factors and can occur together. It’s important that you correctly identify the early symptoms for the treatment to be affective. If left untreated or not treated early enough, these diseases are fatal. Prevention of lambing sickness and milk fever is far better than trying to cure them.
This guide explains the causes of lambing sickness and milk fever, as well as how to prevent them, identify symptoms, and treat them.
Causes of lambing sickness and milk fever
Lambing sickness (pregnancy toxaemia) and milk fever are metabolic diseases often caused by poor nutrition.
Lambing sickness caused by poor nutrition
Lambing sickness is caused by an imbalance between energy supply and demand due to poor nutrition. It occurs in the last 2 months of pregnancy when 70% of lamb growth is happening. It more commonly affects ewes pregnant with twins, even if they haven't had nutritional problems earlier in their pregnancy.
Ewes suffering from lambing sickness might look like they're in good condition, but their nutritional levels will have fallen due to a variety of reasons, such as pastures lacking nutrients.
Milk fever caused by calcium deficiency
Milk fever is caused by a calcium deficiency in the bloodstream, usually occurring in the last 6 weeks of pregnancy and the first 3 months of lactation when calcium needs are the highest. Ewes could already be prone to a calcium deficiency due to a lack of calcium in the diet.
For example, ewes feeding on poor quality pastures or grain diets without added calcium, or grazing oxalate-containing plants that bind calcium in the intestines, preventing absorption, are susceptible. Older ewes are more susceptible to milk fever.
Dietary and environmental triggers of lamb sickness and milk fever
Certain dietary and environmental factors can place extra stress on ewes and trigger the onset of lambing sickness and milk fever. These factors in late-pregnant ewes include:
- mustering for shearing or crutching
- holding off feed for long periods such as in the yards for shearing or crutching, or while trucking
- severe cold, rain or wind that cause ewes to seek shelter rather than graze, and the extra muscular contractions required for shivering and maintenance of body heat that exhaust low energy reserves
- sudden change of diet, for example onto lush pastures, resulting in dietary upsets or being held in eaten-out holding paddocks.
Also consider...
- Find out more about sheep health and disease prevention.
- Learn how to manage ewes for successful sheep breeding.
Symptoms of lambing sickness and milk fever
Symptoms of lambing sickness and milk fever in heavily pregnant ewes are often very similar.
You can identify early signs of the diseases during mustering or yarding for the pre-lambing shearing or crutching. Signs include drooping of the head, lagging behind the rest of the flock and walking aimlessly.
You'll need to examine ewes displaying these signs and consider their recent history to work out the right diagnosis. Then you should start treatment as soon as possible while it can still be effective.
Identifying the typical symptoms of lambing sickness and milk fever
Lambing sickness | Milk fever | |
---|---|---|
Disease progression | Slow progression of the disease with death after 5-7 days. | Rapid progression of the disease with death after 6-24 hours. |
Early and late signs |
Earliest signs:
In the later stages:
|
Earliest signs:
|
Recumbency (lying down) |
|
|
Response to treatment |
|
|
Post-mortem findings |
|
|
Diagnosing and separating sick ewes
Milk fever can also be involved in the death of a ewe that you see displaying rapid signs of lambing sickness.
If you run more intensive sheep-raising conditions, it's a lot easier to tell the diseases apart. You'll be able to observe the sheep more often and over longer periods of time, letting you differentiate between the early signs more easily.
If you see any of the early signs during mustering, don't force affected ewes to continue. Retrieve them in a vehicle, hold them in the yards or a small holding paddock and follow the appropriate treatment.
Also consider...
- Find out more about sheep health and disease prevention.
- Learn how to manage ewes for successful sheep breeding.
Preventing and treating lambing sickness and milk fever
Early treatment of lambing sickness and milk fever results in the best outcomes for ewes and lambs; however, prevention is always preferable.
Preventing lambing sickness
You can avoid lambing sickness by recognising and anticipating any decline in the level of nutrition in the pasture. You can then provide better pastures or energy and protein supplements to meet the increased nutritional requirements of pregnant ewes. Avoid periods when the ewes won't be feeding, such as yarding.
You should feed your ewes energy supplements 2-3 weeks before mustering, shearing, crutching or lambing to ensure their energy status is improved in time. If necessary, continue feeding the supplements during shearing or crutching.
Preventing milk fever
To help prevent milk fever, you should minimise any stress to heavily pregnant ewes. Provide a well-balanced diet and avoid placing hungry stock and/or pregnant ewes in paddocks with lots of plants containing oxalate. Feed as much calcium as possible to your ewes after lambing, for example, in clover-dominant pasture. Provide supplementary feed if necessary. If you supplement feed with grains (which are low in calcium) you can include the 1.5% finely ground limestone (calcium carbonate) to increase the levels of calcium.
Where possible, only hold the first run of heavily pregnant ewes in the yards overnight when shearing or crutching and minimise the time they are in the yards.
Treating lambing sickness
If you can treat ewes with lambing sickness soon after you notice the earliest signs and while they are still reasonably alert, they are more likely to recover. Once ewes have become drowsy, treatment is less effective.
You can give ewes an energy solution (e.g. molasses) or a glucose or propylene glycol drench, followed by a subcutaneous injection of a commercial calcium solution (with added glucose). Always follow the doses and instructions on the label. Follow-up treatments may be necessary.
You should administer the commercial calcium solution injections under the skin of the neck, shoulder or over the ribs. You can massage the area you injected to help distribute the solution. If you're administering larger doses, you should inject in different places.
These injections aren't recommended as the only treatment for lambing sickness as relapses often occur, but they have the advantage of also treating any milk fever that may be present.
You may need to drench affected ewes with up to 1L of water to help overcome dehydration. Make sure that there is accessible water and shade for them. You also need to provide adequate soft feed such as grain or lucerne hay which is necessary to keep the digestive system working and provide enough energy.
Once your ewes start showing signs of lambing sickness, you should provide energy supplements to the rest of your stock as soon as possible to minimise the risk of further cases.
Treating milk fever
You can treat milk fever with an injection of a commercial calcium solution. You will see a rapid response (within half an hour) after injecting affected ewes.
Milk fever can be accompanied by lambing sickness, so commercial calcium solutions with added glucose, magnesium and phosphorous are the ideal medication to keep on hand for both conditions. These include Calcigol Plus and Flopak Plus (4 in 1) that are readily available from your local agent. Always follow the doses and instructions on the label.
Also consider...
- Find out more about sheep health and disease prevention.
- Learn how to manage ewes for successful sheep breeding.
- Learn more about sheep health, grazing and pasture on the Making More From Sheep website.
Supplementary feeding for sheep
Supplementary feeding is the additional supply of feed containing energy, protein or vitamins and minerals to grazing sheep that may be lacking in the pasture. It is important to ensure that the whole diet of the animal, including supplement and pasture, is balanced.
Supplementary feeding can be used to meet the nutritional needs of sheep at varying stages of their life, to increase their consumption of dry pasture, specific nutrients, or to improve growth rate, fertility, meat production or wool quality. Nutritional needs of sheep vary depending on age, size, pregnancy and lactation.
Feeding supplements has benefits and costs. If used effectively to overcome a nutritional deficiency or meet additional nutritional needs, the result can be healthy sheep that grow, reproduce, rear offspring and produce quality wool. However, supplementation can be expensive, time consuming and, if done incorrectly, can have severe impacts on the health of the sheep, even resulting in death.
This guide explains when and how to use supplementary feeding to improve production and keep sheep farms viable in dry season or drought. It will also help you decide when supplementation is likely to be cost-effective.
© The State of Queensland 1995–2024
- Last reviewed: 08 Sep 2021
- Last updated: 08 Sep 2021