Outbreak of follicular conjunctivitis associated with the diagnosis of anaplasmosis in a sheep herd.

Objective: To report an outbreak of follicular conjunctivitis in a group of sheep diagnosed with Anaplasma spp., without any other co-infection.

Animals Studied: In all, 18 animals from a sheep head, males and females, from eight months to four years of age, were assessed for follicular conjunctivitis.

Procedures: The procedures performed included general physical and ophthalmological examinations; PCR evaluation for infectious agents; analysis of hematological parameters, microbiological tests of ocular swabs, coproparasitological examination, histopathological examination of conjunctival biopsy.

Results: All 18 animals had uni- or bilateral follicular conjunctivitis, and one animal also had unilateral uveitis. The results of microbiological analyzes were negative for Moraxella spp., Staphylococcus spp., and Pseudomonas spp., and PCR analysis results were negative for Chlamydia spp., Mycoplasma spp., and Toxoplasma gondii. Anemia, thrombocytopenia, lymphocytosis, and an inclusion body in some erythrocytes, compatible with Anaplasma and PCR analysis for Anaplasma spp. were positive.

Conclusion: Anaplasmosis may be associated with follicular conjunctivitis in sheep and should be included in the differential diagnosis list and investigated in cases of conjunctivitis in herds.