Ketosis / Pregnancy toxaemia

Ketosis, or pregnancy toxaemia, occurs in cattle, sheep and goats. It is caused by the abnormal metabolism of carbohydrates and volatile fatty acids. Ketosis usually occurs in animals in good condition that suffer a sudden deterioration in their nutritional status.

Conditions when ketosis is likely to occur

• late pregnant cows, ewes and does in the last six weeks of pregnancy grazing:
  • dry poor quality pasture of less than 1,000-1,500kg DM/ha
  • stubbles or green pasture of less than 800kg DM/ha
• fat cows, ewes or does with a fat score greater than 3.5-4 or light cows, ewes or does on very poor pasture
• twin-bearing ewes or does
• previous history of pregnancy toxaemia
• cold, wet, windy weather
• extensive grazing situations where the last third of pregnancy coincides with a late break in the season, followed by cold weather that leads to poor pasture growth
• short periods without feed such as yarding
• stress due to climatic conditions, handling, being chased or management procedures
• heavy worm infestation

Identification and diagnosis

Clinical signs that would lead you to suspect ketosis include the following:

• cattle – pregnant and recumbent or showing neurological signs such as staggering, aggression or delirium (often associated with another disease)
• sheep and goats –pregnant and apparent blindness, staggering, star gazing, drowsiness or convulsions.

Prevention

An integrated approach to prevent ketosis should consider the following:

• avoiding grazing of cows, ewes and does on pasture when rapid weight loss is likely in late pregnancy or supplementing to avoid rapid weight loss
• avoiding cows, ewes and does getting too fat (i.e. fat score greater than 3.5-4) or too thin (i.e. fat score less than 2-2.5) in late pregnancy
• avoiding handling heavily pregnant animals