Valiant's troubles began when he stepped on a horseshoe nail. Despite prompt veterinary care, a raging bacterial infection developed in his bloodstream and other organs that nearly killed Valiant. Various powerful antibiotics including Penicillin were utilized to treat this overwhelming and potentially fatal infection. The bacteria in the blood also migrated to the inside of his eyes. The eye has weak defense mechanisms against infection. Aggressive therapy for this 'endophthalmitis' could not prevent the destruction of Valiants eyes and the subsequent blindness.