Ketosis

Introduction

Ketosis occurs in starvation and also in diabetes mellitus, ketosis of cattle and pregnancy toxaemia of sheep. Basically, no carbohydrates are metabolised, in starvation none are available and in diabetes mellitus because there is no insulin present to allow glucose transport into cells. When carbohydrates are not available the body produces energy via the metabolism of fat. Fatty changes can be seen in the liver and kidney following deposition of the mobilised fat. This results in an accumulation of ketone bodies (B-hydroxybutyric acid, acetoacetic acid and acetone) in the blood and other tissues. Two of the ketone bodies are acids resulting in a metabolic acidosis hence the name ketoacidosis.

Signalment

Affects cattle, ewes and deer, diabetic dogs More frequently affecting animals who have a high body condition store.

Diagnosis

This condition can often be diagnsis on clinical signs combined with simple tests. It is possible to test milk or urine on the farm for the presence of ketone bodies. This can be carried out using dipsticks which change colour in the presence of ketone bodies. False positives can occur with these tests and they should be used in conjunction with clinical signs suggestive of ketosis.

Additionally, serum concentrations of NEFAs will be high and glucose levels will be low.

The acetone that is formed during ketosis is a volatile agent which can be blown off and this accounts for the 'pear drop' like smell on affected animals breath.

Clinical signs

Include, depression, lethargy, dehydration, anorexia and decreased rumenal activity.

References

See also: Ketosis of cattle — Pregnancy toxaemia of sheep