Ocular Lesions of Bovine Malignant Catarrhal Fever

Abstract

Abstract. The ocular lesions of bovine malignant catarrhal fever were characterized in 15 naturally occumng and eight experimentally induced cases of the disease. Consistent findings included: lymphocytic vasculitis of retinal, scleral, posterior ciliary, and uveal vessels; uveitis, especially involving ciliary processes, ciliary body, and iris; and keratitis with corneal edema, neovascularization, and epithelial and endothelial degeneration. Lymphocytic ciliary neuritis and optic meningitis were found less frequently. Ultrastructural examination of the ciliary body and iris from one experimental calf confirmed that most infiltrating mononuclear cells were lymphocytes. The uveitis, vasculitis, and keratitis of malignant catarrhal fever were probably immune-mediated.Malignant catarrhal fever is a viral pansystemic vasculopathic disease affecting cloven-hooved animals. In cytes from clinically affected animals were injected intraperitoneally or intravenously into Holstein-Fresian calves. Calves late (4) stages of clinical involvement. Clinical stages were response, lymph node enlargement, degree of ocular and nasal involvement, and physical debilitation.For light microscopic examination, eyes were removed from the orbit, trimmed of extraocular tissue, fixed in Zenker's acetic acid solution, embedded in paraffin, sectioned at 6 to 8 Fm, and stained with either hematoxylin, phloxine, and safranin or hematoxylin and eosin (HE).Tissues from one experimental calf were available for ultrastructural examination. Detailed procedures were previously reported.'' Briefly, tissue was immersion-fixed in Sorensen's phosphate-buffered 3% glutaraldehyde, post-fixed in 2% 0s-mium tetroxide, dehydrated in ethanol and acetone, and embedded in epon. Thick sections were cut with glass knives and stained with azure 11-methylene blue. Thin sections (silver) were cut with a diamond knife, placed on 100 mesh copper grids, stained with uranyl acetate and lead citrate, and examined in an Africa, a virus has been proven to be the etiologic were necroPsied during the early (2 animals), middle (219 O r agent20 and is as an alcelaphine hemesvirus-determined by the occurrence and duration of the febrile 7 based Won the classification Of the in the subfamily Alcelaphinae. 25 In the United States, a specific etiologic agent has not yet been isolated from naturally occurring cases.27Ophthalmic lesions of malignant catarrhal fever have been described in the German 1iterature,l2 but only brief descriptions have appeared in the English literature. ', I5 We review ocular lesions in 15 spontaneous and eight experimentally induced cases of malignant catarrhal fever as a basis for the consideration of pathogenetic mechanisms that may be involved in the genesis of ocular lesions in this disease. Materials and MethodsNatural cases of bovine malignant catarrhal fever that occurred between 1971 and 1983 were selected from the Colorado State University pathology archives. These cases involved beef and dairy cattle and included females and castrated males from ...

Clinical ocular findings in cows with malignant catarrhal fever: ocular disease progression and outcome in 25 cases (2007–2010)

“…The anterior segment abnormalities found in our study were similar to those reported in the literature 1,15–17,19,20,23,25–27,31,32,37,38,44–50,53 …”

“…We have decided to evaluate corneal edema separately, because in cows with MCF, it is not exclusively a consequence of uveitis‐induced loss of corneal endothelial function. In one report, it was stated that peripheral corneal edema was most probably caused by MCF associated vascular and epithelial changes 37 . More importantly, we have tried to establish a practical grading scheme for corneal edema, which can be easily used by general practitioners, since it does not require any special equipment or skills, as are needed for the detection and grading of anterior uveitis.…”

“…Persistent bilateral leucomas were reported to be the most distinct clinical feature in cattle recovered from MCF in one study 25 . Although panophthalmitis is present on histopathology, posterior segment lesions are often difficult to detect clinically due to anterior segment lesions 37,49,50 …”

“…The predominant lymphoid cells are CD8+ T lymphocytes 33–35 . Besides lymphoid organs, the respiratory and alimentary tracts are primarily affected, 36 and the eyes are frequently affected as well 1,23,37,38 . Generalized obliterative arteriopathy was reported as a characteristic feature in cows with chronic MCF, as well as in animals that recovered from the disease 25 .…”

“…The ocular symptoms include exophthalmos, blindness, nystagmus, photophobia, lacrimation and mucopurulent ocular discharge, blepharospasm, eyelid edema, episcleral injection, and other symptoms of conjunctivitis, keratitis, and anterior uveitis 1,15–17,19,20,23,45–49 . Corneal edema is a typical and easy to diagnose symptom of the ‘head and eye’ form, and can vary from mild perilimbal to dense complete corneal edema 23,37,44,47,49 . Corneal ulceration is uncommon, 37 but can result in corneal perforation and iris prolapse 25 .…”