Ketosis in the Dairy Cow

What is ketosis?

Ketosis is a metabolic disease that usually affects dairy cows

in the first month after calving. It occurs when there is a mismatch

between a cow’s energy intake (i.e. food) and energy output

(i.e. energy used for maintenance and milk production).

This is called ‘Negative Energy Balance’ (NEB).

Cows then compensate by mobilising fat stores,

which in turn leads to the production of ketones.

High levels of these result in disease.


Ketosis can also occur in cows that are too fat when calving down.

Cows with a body condition score (BCS) of 3+ are likely to have

poor appetites after calving. This puts them at risk of NEB.

They also mobilise more fat more quickly, which can damage their livers.

This in turn causes ketosis.


Signs to look out for:

Cows with ketosis may:

  • Be thin/ losing condition (‘milking off her back’)
  • Show a drop in milk production (Can start out gradually then suddenly drop off rapidly).
  • Refuse to eat concentrates.
  • Have a sweet ‘pear drop’ smell to their breath (not everyone can smell this!!).
  • Show nervous signs (RARE) – head pressing/licking/circling/anxious.

Cow with Ketosis, 6 weeks post calving. Note the poor body condition. 


Treating a case of ketosis involves drenching with propylene glycol, injecting steroids and vitamins. One clinical case of ketosis is often the ‘tip of the iceberg’, with many more subclinical cases being present within the herd. As such, prevention is better than cure.


Why is ketosis important?

Ketosis is costly! It has been estimated that the effects of ketosis cost 2.9p per litre of milk produced.

Direct costs include:

  • Vet bills
  • Stockman’s time
  • Discarded milk

Indirect costs include:

  • Increased risk of disease associated with calving- 3 times more likely to be ‘dirty’ cows
  • Increased risk of LDA
  • Increased risk of Culling
  • Decreased Fertility- 6 times more likely to be cystic
  • Decreased Milk yield and quality


Steps  to help prevent Ketosis

Aim to calve down at BCS 2.5 -3.0.

To accurately calculate a cow’s BCS, use the Dairy Co Condition Score System. We have free laminated copies of these charts in the surgery (ask a vet or receptionist). Any changes to BCS should be made in late lactation, with thin cows being fed to gain weight, and fat cows to lose weight. Cows should then maintain their weight through the dry period.


Focus on diet

  • Introduce transition diet (e.g DCAB/adjusted milking ration) to the dry cows from 2-3 weeks before calving to allow the cow’s rumen time to adjust.
  • Maximise palatability- Feed good quality forage or TMR to improve feed intake.
  • Maximise feeding time- Keep food ‘pushed up’ and ensure appropriate amount of feeding space.
  • Avoid sudden changes to the diet


Kexxtone boluses

These can be used as a one off preventative measure in high risk cows during the dry period.  High risk cows include overfat (BCS 3+), thin (BCS <2.5), or older cows (3+ lactations) and those carrying twins. The active ingredient in the boluses is Monensin. This works on the rumen to aid conversion of food to energy, thus helping to prevent ketosis. The boluses can be used 3-4 weeks before calving, in order to give the rumen sufficient time to adjust. They are slow release, so will also cover the cow for the first 70 days of lactation. They have 0 day withdrawal period for both milk and meat. They cost under £30 per bolus, and require an applicator.


Identify cases

Ketotest milk sticks offer a simple way to test for ketones in milk. Simply dip the stick into a sample of milk, and if ketones are present a colour change will occur. These tests are available from the practice and can be used in cows from 2-21 days of calving.

Remember, early detection= early treatment = early cure

For any further advice or information regarding ketosis or Kexxtone, please ask a member of the large animal team.