Ocular disease in horses with confirmed ocular or central nervous system Borrelia infection: Case series and review of literature

Abstract

Objective To describe the clinical presentation, treatment, and clinical outcome of horses with ocular disease and evidence of systemic or ocular Lyme disease. Animals Studied Five horses met the inclusion criteria of ocular disease with evidence of B burgdorferi present in ocular or CNS tissues. Procedure The goal of this study was to describe the clinical presentation and progression of ocular disease when associated with ocular or CNS B burgdorferi infection in horses. A retrospective review of medical records was performed on horses admitted for ocular disease with evidence of B burgdorferi infection between 1998 and 2015. The diagnosis of B burgdorferi‐associated uveitis was based on histopathologic lesions of lymphohistiocytic and suppurative uveitis/endophthalmitis and intralesional argyrophilic spirochetes in either ocular or CNS tissue consistent with Borrelia. Leptospiral uveitis was ruled out by PCR. Results All five horses in the current study had intraocular inflammation at the time of presentation. Medical management with anti‐inflammatories was successful in controlling uveitis in the two horses in which treatment of uveitis was attempted. Systemic treatment with oral tetracyclines was unsuccessful in a single case in which treatment of Borrelia was attempted. Four horses were euthanized due to progression of neurologic disease. The surviving horse had an enucleation performed and did not show systemic signs. Conclusions Infection with Borrelia burgdorferi should be considered in endemic areas as a differential for horses with ocular disease, in particular, uveitis. The prognosis for uveitis and neurologic disease associated with Lyme disease was poor in the current study.

Genomic hybrid capture assay to detectBorrelia burgdorferi: an application to diagnose neuroborreliosis in horses

“…9 The reasons might be early infection prior to production of measurable serum antibody, an immune deficiency, or infection only in privileged sites, such as the eye and CNS. 9,13,16 Detecting B. burgdorferi in the CSF can be crucial in the antemortem confirmation of equine neuroborreliosis. Antigen or DNA detection tests such as PCR, fluorescent in situ hybridization, and silver staining of diseased tissue have successfully confirmed neuroborreliosis in deceased horses.…”

“…7,9,13 Antemortem detection of B. burgdorferi DNA by PCR in ocular fluid has been successful in documenting Lyme uveitis in horses and, in some cases, the organism could be seen on cytologic examination of the aqueous fluid. 14,16 As noted, conventional PCR testing of CSF from horses and humans with B. burgdorferi neuroborreliosis has low sensitivity, likely because of low numbers of B. burgdorferi in CSF. 2,9,17 Although the specific genomic hybrid capture methodology that we used was able to identify B. burgdorferi in the CSF of a horse with acute onset neurologic signs, finding DNA of an organism in fluid from a diseased animal does not confirm causation of disease.…”

“…9 The reasons might be early infection prior to production of measurable serum antibody, an immune deficiency, or infection only in privileged sites, such as the eye and CNS. 9,13,16…”