Selenium is a crucial element in more than 30 metabolic processes in horses. We explain the topic of selenium deficiency in horses and reveal not only the symptoms and causes but also how to treat it.
Selenium in horses — what is meant by it?
Before we can discuss selenium deficiency, we first have to explain what selenium is. Selenium is a trace element and vital for the body. It protects the cell membranes from harmful influences and helps the horse form antibodies and messenger substances. Furthermore, selenium affects numerous metabolic processes such as fertility, liver detoxification, thyroid function and hair and coat growth.
The daily selenium requirement of a horse is 0.1 to 0.2 mg per kilogram of ingested dry matter. For example, a horse weighing 600 kilograms and consuming approximately nine to eleven kilograms of dry matter needs 0.9 to 2 mg of selenium per day.
Selenium deficiency in horses — symptoms
It is not easy to recognise a lack of selenium in a horse. A slight deficiency often leads to an impaired immune response to infections or an increased tendency to allergies. In addition, a drop in performance is also often noticed. Some horses may develop diarrhea or watery stools too. Selenium deficiency can also cause stiffness, even mild lameness, and disturbances of the entire metabolism.
If a zinc deficiency is also present, this has a strong effect on the horse’s skin or hair. If your four-legged friend suddenly develops sweet itch, hair breakage or hair loss, this could indicate either a zinc deficiency, a selenium deficiency or a combination of both.
Foals, in particular, are often affected and can suffer from muscle loss as a result. Selenium deficiency in foals is often caused by an undersupply in the womb, either due to a disorder in the umbilical cord or due to a selenium deficiency in the pregnant mare. The foal then appears weak, wobbles and, in the worst case, goes lame.
If you suspect that your horse has a selenium deficiency, you can easily verify this by taking a blood sample.
Causes — these may be the reasons
There is too little selenium in the soil, for examle, in Germany, which means that the selenium content in hay or haylage is also insufficient. Within Germany, the content in the soil decreases from north to south, so there can be high regional differences. Other causes are high levels of protein and sulphate in the feed and the increased need for antagonism such as sulphur.
Correcting selenium deficiency in horses — treatment options
If your horse lacks selenium or you want to provide sufficient trace elements as a preventative measure, you can opt for a specially enriched mineral feed. This way, you ensure your horse gets a balanced micronutrient supply and the essential supply of trace elements is given. Beetroots or nuts, for example, have a high selenium content.
Alternatively, the pasture can be enriched accordingly, as there are special fertilisers with sodium selenate.
It is important to feed selenium responsibly so that there is neither a deficiency nor an oversupply, which can also be dangerous. It is best to discuss the matter with an expert who is familiar with the subject before the first dose.