LAUSR

All animal species as well as humans have bacterial and fungal commensal flora in the conjunctival sac (10). Literature reports the presence of fungi such as Aspergillus spp., Penicillium spp., Scopulariopsis spp. and Microsporum spp. in the conjunctival sac of clinically healthy horses (including newborn foals) (1, 10, 15, 17, 19). Bacteria, including Streptococcus spp., Staphylococcus spp., Pseudomonas aeruginosa, Moraxella spp. and Corynobacterium spp., can also be isolated from the conjunctival sac of healthy horses (1, 10, 11). These bacteria exacerbate ulcerative keratitis (1, 10, 11, 16). The identification of the commensal microbiota in the conjunctival sac of horses is essential for a correct diagnosis. There have been no reports to date of the isolation and culture of viruses from the conjunctival sac in healthy horses. The most common viral ophthalmic pathogen in horses is the Herpesviridae group (6). Equine herpesvirus-1, belonging to the alpha-herpesviruses group, in addition to respiratory, nervous and reproductive disorders, may be the cause of retinopathy (8). Viruses belonging to the gammaherpesviruses group are mainly responsible for viral keratitis in horses (8). Moreover, equine herpesvirus type 2 has an affinity for conjunctival epithelial cells (4). Other viruses can also cause conjunctivitis in horses: Equine Arteriritis Virus (EAV), Equine Influenza Virus (EIV) or less frequently adenoviruses (2, 3, 6, 7). The most common ocular signs include eye discharge (mucous to purulent), redness and conjunctival oedema and photophobia (6). The aim of the study was to determine whether viruses responsible for ocular and upper respiratory tract disease (EHV, EIV, EAV) can be isolated from the conjunctival sac of clinically healthy horses.