Taking blood is a procedure very commonly performed and is done for a number of reasons. Sometimes it is to test for a certain disease in particular- for example evidence of strangles, although most of the time we take blood in order to get more information that allows us to work out what condition your horse may be suffering from.

Most of the time we will ask the laboratory to perform two types of test.

• Haematology
• Biochemistry

Haematology involves testing the cells found in blood (red blood cells, white blood cells, platelets). By measuring these we are able to identify anaemia, infection and inflammation.

Biochemistry involves measuring enzymes and chemicals within blood that are produced by different organs and metabolic processes.

The normal levels of enzymes are well known, so when blood results are produced we compare your horse’s enzyme levels with those deemed normal for another horse of the same age.

The main organs we access are liver, kidneys, and muscles, in addition to inflammatory enzymes sometimes associated with infection.

For example- if we found a horse had elevations in its liver enzymes we may suspect it of having a problem with its liver.

The horse below appeared very stiff and reluctant to move after exercise. Bloods were taken which are shown. AST and CK are both enzymes produced by muscles. As you can see they are massively elevated compared with normal levels. This would be consistent with tying up (exertional rhabdomyolysis).

Sometimes we will monitor the progression of a disease through repeated blood tests. By monitoring enzyme levels we are able to recognise whether a horse is getting better/ worse and hence tailor treatment according to the results obtained.