Influence of Extended Photoperiod Using Blue Light Masks on Hypertrichosis, Coat Condition, and General Health Parameters in Horses with Pituitary Pars Intermedia Dysfunction

The study examined the effects of blue light masks on 52 horses over 15 years old with Pituitary Pars Intermedia Dysfunction (PPID), a condition causing excessive hair growth. Horses were divided into three groups: one with blue light masks, one medicated control, and one unmedicated control. The blue light group showed no difference in hair length compared to the medicated group but had shorter hair than the unmedicated group. However, they began shedding earlier in spring, had improved coat condition, reduced fat coverage, and increased energy. A survey indicated better coat condition, fewer PPID symptoms, and improved quality of life in the blue light group, suggesting blue light masks may help manage PPID symptoms and warrant further research.