Analysis in horse hair as a means of evaluating selenium toxicoses and long-term exposures.

This research article investigates the use of horse hair analysis as a method to assess selenium toxicity and long-term exposure in horses fed on seleniferous forages.

Research Context

• Chronic selenosis is a condition affecting horses that have been allowed to graze on seleniferous forages for extended periods. This condition is characterized by specific hoof lesions, among other symptoms.
• Selenium, or Se, is an essential trace element for many life forms, but excessive consumption can lead to toxic effects.
• The researchers hypothesized that analyzing hair samples from affected horses could provide a tangible record of selenium exposure.

Methodology

• Horses were allowed to graze in a pasture containing seleniferous forages and water for six months each year, which is from the mid-May to mid-November, for three consecutive grazing seasons.
• Hair samples from the mane and tail were taken from horses exhibiting classical symptoms of chronic selenosis.
• The hair samples were analyzed using inductively coupled plasma mass spectrometry, a highly sensitive technique that can quantify selenium content.

Results

• The segmented hair samples indicated a cyclic pattern of selenium concentrations, which aligns with the timing of the horses’ presence in the contaminated pasture.
• In one horse, selenium levels could be traced back to three grazing seasons of exposure.
• The researchers concluded that, in certain cases, hair samples can offer a valuable tool to determine selenium exposure in horses for up to three years after contact with seleniferous forages.

Implications

• The findings offer a new non-invasive way to detect selenium exposure in horses and could hence improve the disease management of chronic selenosis.
• The research adds to our understanding of chronic selenosis in horses and increases the potential for more effective prevention strategies against selenium toxicity.