OCULAR HALICEPHALOBUS (SYN MICRONEMA) DELETRIX IN A HORSE

Ocular contents from a horse with a 4-week history of severe unilatera l uveitis were submitted for histopathologic examination. A severe uni lateral granulomatous chorioretinitis with intralesional Halicephalobu s deletrix was diagnosed. The horse developed progressive neurologic s igns several days following the surgery to remove ocular contents and implant a prosthesis and was subsequently euthanatized. A severe multi focal granulomatous encephalitis with intralesional H. deletrix, local ized primarily to the optic chiasm, thalamus, and brain stem, was diag nosed from tissues acquired at necropsy. The other eye was not affecte d. This is the first report of ocular parasitism by H. deletrix and su ggests possible systemic dissemination from a primary site in the eye.