Ketosis in cattle
Also called Hyperketonaemia, acetonaemia
An energy shortage in early lactation. The cow burns body fat faster than she can use it, ketones build up, and she eats less and gives less milk.
Cause and spread
- Cause
- Heavy fat breakdown together with a very high demand for glucose, typical of the first weeks after calving in high-yielding dairy cows.
- How it spreads
- It is not infectious. It is a feeding and metabolic problem, most common where dairy animals are bred and managed for high production.
Signs to watch for
- Reduced appetite and falling milk yield
- Weight loss and loss of body condition
- Firm, dry dung
- Sometimes nervous signs: unusual licking, staggering, bellowing, aggression
- Hidden (subclinical) ketosis with no obvious signs, only raised blood ketones
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
Ketones, especially beta-hydroxybutyrate (BHB), can be measured in blood, milk or urine. A blood BHB result is the most reliable way to tell whether a cow has hidden or clinical ketosis, and to monitor a herd.
Prevention and control
- Manage body condition in late lactation, when cows tend to become too fat; trying to slim cows in the dry period can backfire
- Protect feed intake around calving: cows eat less in the last 3 weeks of pregnancy, so reduce stress and keep feed always available
- Check cows in the first weeks after calving, and test cows that go off feed
- Treat promptly under your veterinarian's guidance
Where this information comes from
- Hyperketonemia in Cattle · Merck Veterinary Manual
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.