Neem oil has many benefits for horses. It can create a waterproof barrier, ensuring that your horse does not get mud attached to it, and keeping it clean. It can also promote hair growth, and help scabs and itching heal. Another benefit of neem oil for your horse is the smell can serve as a natural repellent for insects and flies that can cause irritation or harm to your horse. It is perfectly safe to use.
To apply neem oil to your horse, mix 1 part of oil with 20 parts of water, and spray. It is safe to use when the sun is shining, and when diluted.