Keratoconjunctivitis Associated with Neisseria Ovis Infection in a Herd of Goats

Clinical signs appeared in a herd of 18 goats 6 weeks after being collected and placed in a research holding facility.Three goats developed bilateral epiphora, photophobia, and blepharospasm.One goat walked into objects in the pen.Affected animals were not separated from normal ones because of housing limitations.Twelve days after the initial signs were observed, there was 100% morbidity.An ophthalmic examination and consultation were requested.Each goat had bilateral ocular disease, but severity varied among animals.Photophobia, blepharospasm, and a serous discharge from the medial canthus were present.Several 0.5to 1-mm raised, transparent conjunctival follicles were present at the dorsal limbus (Fig. 1).Increased peripheral cornea1 relucency from stromal edema and subepithelial cornea1 neovascularization was present (Fig. 2).One severely affected doe had full thickness cornea1 edema that prohibited observation of the left anterior chamber by focal penlight examination.In the right cornea, there was superficial uptake of fluorescein stain.a The pupils were normal in goats with only conjunctivitis but were miotic in goats with keratitis.All goats with severe cornea1 involvement were examined by direct ophthalmoscopy and were normal.No other abnormality was found on physical examination.Etiologic agents considered in this herd included 1) Mycoplasma spp.(M.agalactia, M. mycoides mycoides), 1,8,12 2) Chlamydia psittaci, 8,12 3) aerobic bacterial.1,12 (Neisseria ovis, Staphylococcus spp., Streptococcus spp., Moraxella spp., Escherichia coli, Pseudomonas spp., Corynebacterium pyogenes, Listeria monocytogenes), [3][4][5]8,10,12 4) Colesiota conjunctivae ("Rickettsia conjunctivae"), 1,12 and 5) infectious bovine rhinotracteitis virus (IBR).8,12 Parasitic keratoconjunctivitis, resulting from Oestrus ovis, Trypanosoma spp., or Thelazia spp., and fungal keratoconjunctivitis 8 were considered unlikely.Trauma was excluded because of herd history and clinical findings.Toxicosis and topical irritants were also considered.Conjunctival swab specimens from all goats were submitted for bacterial, viral, mycoplasmal, Chlamydial, and rickettsial isolation prior to administration of topical anesthetic.b Neutrophils and occasional gram-negative coccobacilli were