open access Following infection, the first sign is fever, peaking at 41 Coulomb , followed by various signs such as Lethargy, nasal discharge, "pink eye" (conjunctivitis), swelling over the eye (supraorbital edema), urticaria, and swelling of the limbs and under the belly (the ventral abdomen) which may extend to the udder in mares or the scrotum of male horses.