First there was UltraShield and now there's UltraShield EX, the new standard in fly control protection from Absorbine. UltraShield EX is the first weatherproof, sweat-resistant formula that can provide 17 days of fly control. It's the hardest working insecticide-repellent around and it can even be used on dogs.The most advanced, ready-to-use fly, mosquito and tick repellent available. Sweat-resistant, weather proof and contains two sunscreens. Kills and repels insects for 17 days, including mosquitoes that transmit West Nile Virus. Made with natural Pyrethrins (from chrysanthemums), Permethrin and Piperonyl Butoxide. Use on horses, ponies, dogs, stalls and bedding.