My friend has a horse allergy. any remedies?

Yes: Consider allergy immunoherapy (allergy shots) to horse hair.

allergy shot vs med: See an allergist to verify it is a horse allergy and not another allergen at the farm ie hay, grass etc. Medications such as antihistamines and intranasal steroid sprays can help with symptoms. There are no standard for horse allergy shot but there have been cases that report their effectiveness. Trial of horse allergy immunotherapy may provide a more permanent treatment.