Time to say good-bye to fungi with Fungasol Fungal Treatment Horse Spray! This gentle water-based spray includes Biopolysan—a patented coconut-derived booster ingredient that helps improves efficacy—and tea tree oil to help treat various skin conditions. A go-to product for a number of skin ailments including rain rot, dry skin, bacterial wounds and ringworm, Horse Spray is formulated to penetrate thick coats. Simply spray it on, concentrating on infected areas.