Ketosis in cattle is associated with an inadequate supply of the nutrients necessary for the normal carbohydrate and fat metabolism that is seen mainly in times of high milk production in early lactation. The excessive ketone bodies in the bloodstream come from the breakdown of fat when the animal is forced to draw on its bodily reserves for energy. Although the metabolism of body fat provides energy for cows, the nervous system is dependent on glucose, and the ketones produced as a result of excessive fat metabolism can have toxic effects. The excess ketone bodies are eliminated in the urine, milk and breath of the animal.
Ketosis may develop from poor diet or periods of stress such as cold, wet weather. It may also affect apparently well-fed cows producing very large volumes of milk. In pasture-fed cows the condition is usually seen when the grass is drying off and green feed is scarce.
The disease is relatively common in lactating cows in Australia but often goes unnoticed in its mild forms. The mortality rate in affected cattle is low and spontaneous recoveries occur in many cases. The disease is usually seen in early lactation (within the first 2 months after calving) and may cause significant production losses.
Five types of the disease are recognised:
|Signs of the disease|
In the more common wasting form, there is a decrease in appetite and milk yield. There is an associated loss of weight, firm faeces and the cow becomes depressed. With recovery there is a gradual return to normal milk production.
In the nervous form, affected cattle excessively lick and chew or grind their teeth. The cattle may also walk aimlessly and appear blind and become recumbent.
In sub-clinical ketosis, clinical signs are not seen but ketones are present in the milk and urine.
A veterinary examination may be necessary to confirm the presence of the disease. Ketosis is characterised by a high blood ketone level and a low blood glucose level. A test is available which will detect the presence of ketones in the urine and this is a good guide as to the existence of the disease.
Treatment is best undertaken by your local veterinarian.
The aim of treatment is to:
Treatment may include:
Failure to respond to treatment within two days indicates that there may be another, underlying problem which should be identified and treated.
Ketosis causes financial loss through lost production and treatment. It may be prevented by management strategies that maintain a good appetite and supply adequate feed to meet this appetite during the late dry period and immediately after calving. These strategies include:
It is also important to ensure that any health problems (calving difficulties, abomasal displacement, milk fever) are identified and treated as early as possible.