Take a sample of your horse’s hair and find out exactly what he needs in his diet, and his current state of health. Sounds great! But is it possible? Sadly, not yet.
Hair can be analysed to detect past drug intake, and this has been investigated by UK researchers. If enough validation is done, it could be used in the future to determine performance enhancing drug use over long periods of time. It can also be used to detect toxin intake. Researcher Dr Mark Dunnett investigated the potential for hair to be used to detect whether or not a horse had eaten ragwort. He looked for the toxic alkaloids from ragwort plants and found that horses who showed clinical signs of ragwort poisoning had detectable levels of alkaloids in their hair, corresponding with the time of intake. The hair colour affected the concentration of toxins in the hair, due to the binding of certain substances with the melanin pigment. Dunnett continues with this work, which needs to be developed further before it is practically useful.
Horse hair has been analysed for toxic heavy metals including cadmium and lead, and also for the essential micromineral selenium, which is toxic in high levels. Horse hair selenium was linked to serum concentrations and it does reflect past intake of this mineral.
Hair could be a very useful indicator of dietary mineral intake or balance. It contains high enough mineral levels to be measured and samples are convenient and easy to take. Hair is not yet, however, a reliable indicator of whole body mineral status. There is not enough research to correlate mineral levels in hair with the mineral status in the body. There are differences in mineral levels of hair from different breeds of horse, and in hair of different colours. Tests of two different colours of hair from one horse showed differences in mineral levels. Increasing dietary calcium in ponies did not cause increased calcium levels in their hair. Hair concentrations of calcium and phosphorus seemed to be linked to the rate of hair growth during different seasons. Researchers showed higher levels of zinc and calcium in the hair of horses with a heart condition called atrial fibrillation, but further validating research is necessary before this could be used practically.
For the time being, the most reliable and accepted method to assess the nutrient status of horses is to investigate and analyse the diet.