Ocular lesions in mink affected with Aleutian disease.

Uveitis, characterized by infiltrates of lymphocytes and plasma cells, was the principal ocular lesion in 122 sapphire and pastel mink affected with experimental Aleutian disease. It was present to various degrees in all but five mink examined five to 164 weeks after inoculation (intraperitoneal or intranasal) with any of four North American strains of Aleutian disease virus. The uveitis, mostly iridocyclitis, was accompanied often by protein-rich fluid in the anterior chamber and less often by fibrin and cells in the vitreous body. Cellular infiltration of the limbus, seldom pronounced, also occurred in about 20% of the mink. In 11 mink with moderate or severe uveitis, the retina was detached by pools of protein-rich fluid. Infiltrates of lymphocytes, plasma cells, and a few histiocytes often were found in the orbital soft tissues, occasionally in association with retrobulbar arteritis. In general, the ocular lesions were more severe in sapphire than in pastel mink. The uveitis accompanies glomerulonephritis, the principal lesion of Aleutian disease, much more regularly than do several other lesions of the disease. Like the glomerulonephritis, it probably results from the deposition of circulating immune complexes.