Blood Tests in Horses
- Sampling conditions and methods. There are many things that can change the parameters of blood values. These include stress, excitement (even just walking to the track), exercise and feeding. Try to standardise the conditions under which you sample the horse – ideally in a quiet box at rest, after a day of lighter work. If the horse has worked, or was fractious for sampling, please let the vet know so results can be interpreted as needed. Blood should also be collected straight into the vacutainer tubes or if a syringe is used, transferred immediately. The blood should then be taken to the clinic promptly so it doesn’t sit around in the tubes. This can cause cells to deteriorate and artificially change the results.
- Generally (with the exception of selenium) it’s not as simple as taking a blood tests to see if a horse is lacking anything. Blood levels are mostly kept very constant even if there is insufficient intake for requirements.
- It isn’t possible to use a blood test to tell you how fit a horse is. They are not helpful to predict performance except to detect subclinical disease.
- For some conditions, the blood test may not show any change, even though there may be obvious disease. This can happen with localised disease e.g cough, or when an organ such as the liver has a large reserve function.
- Blood tests are mostly not able to diagnose specific diseases such as stomach ulcers, and lameness.
- Routine blood tests performed at the clinic are a great place to start. Sometimes further tests are needed to delve more deeply into an issue. Good communication between vets and horse owners and trainers is essential to get the most out of any diagnostic testing.