Pregnancy tomaemia is a matabolic disorder that affects pregnant ewes late in gestation. Ewes pregnant with multiple foetuses are at a higher risk compared to single bearing ewes.
The condition occurs when blood glucose levels drop and ketone production increases. Pregnancy toxaemia is often fatal. To be successful, treatment must be given in the early stages of the disorder.
Causes
Pregnancy Toxaemia is triggered by a reduction in feed intake. This can occur due to:
The feed available being too low in energy, or there is not enough volume.
An event (yarding, transport, poor weather) interrupting grazing for 12-24 hours.
Lameness
Tooth loss or poor jaw confirmation, particularly in older ewes.
Other metabolic disorders such as hypocalcaemia.
Sudden changes in diet, with or without acidosis
Dog attacks
Overweight and underweight ewes are at increased risk. Overweight ewes (condition score 4/5 or 5/5) may voluntarily reduce feed intake in late gestation. Underweight ewes (condition score is 1/5 or 2/5) do not have body reserves to draw on.
Signs
Signs of pregnancy toxaemia include:
Separation from the flock
Standing still or remaining recumbent when approached
Drowsiness, depression or apparent blindness
Standing in water lapping
Head pulled back or to the side
Tremors and spasms of the head, face and neck muscles
Ewes often progress to recumbency and then death within days.
Treatment
Treatment must be given in the early stages to be successful. The prognosis is poor for ewes showing obvious symptoms, who are no longer eating when feed is offered or are recumbent. In these cases, humane euthanasia should be considered. If unsure, seek veterinary advice.
Pregnancy toxaemia can be confused with hypocalcaemia (low blood calcium levels). The treatment for hypocalcaemia is more frequently successful.
Treatments for individual ewes suffering pregnancy toxaemia include:
Propylene glycol given orally, 50-60ml twice daily or 100-120ml once daily
Glycerol (Glycerine) given orally 120ml every 6-8 hours
Injection under the skin, 120ml of 20% dextrose or 50ml of 50% glucose ( do not give intravenously).
Intravenous infusion of 170ml isotonic saline containing 15% glycerol (vet only)
Glucose Solutions or rehydration solutions, given orally every 4-6 hours as per lavel dose (mild cases only).
For valuable ewes, caesaren section may be considered to remove the demand for glucose.
In all cases continue treating the ewe until she recovers. If the ewe is not responding to treatment, she must be humanely destroyed.
Prevention
A single case of pregnancy toxaemia is a warning to review the mob. Provide additional feed or remove risk factors where possible. Prevention of cases is far better than attempting treatment.
Allocate feed so ewes can maintain their bodyweight at condition score 3/5 throughout pregnancy.
Consider pregnancy scanning so feed resources can be managed and prioritised for multiple-bearing ewes.
Ensure ewes carrying multiple lambs have a high-energy ration during the last six weeks of pregnancy.
Hay is unlikely to be sufficient. Introduce any supplementary feeds carefully. Seek advice from your veterinarian or agronomist as needed.
Monitor ewes in late pregnancy regularly and minimise the stress associated with mustering and yarding. Avoid extended periods off-feed and any sudden changes to feed rations.