Survey of ERU frequency and its associated factors among different horse breeds in riding clubs in Tehran suburb

Equine Recurrent Uveitis (ERU) is the most common serious ocular disease in horses worldwide. The etiology of ERU is still unknown. A similar pathologic mechanism as human was assumed in ERU. A variety of environmental conditions was assumed as predisposing factors for affection with ERU in susceptible horses. Among these factors, the role of infectious agents particularly infection with leptospirainterrogans in the pathogenesis of ERU is overstated. To evaluate both the prevalence and associated factors of ERU among equine population of Tehran suburbs riding clubs, thorough ocular examination was carried out in 951 horses. ERU was diagnosed in 1.05% of examined horses based on clinical, ophthalmoscopic, Ultrasonographic and historical findings. Sera of these patients and control groups were collected and evaluated for serological survey against leptospira, brucella, toxoplasma, equine infectious anemia, equine influenza, parainfluenza type3 and equine herpes virus type1. Fecal samples were collected for diagnosis large strongylus infestation. Odds-ratio analysis revealed that seropositive horses with Pomona serovar of leptospirainterrogans were 2.67 times more likely to affect with ERU than were seronegative ones.