Abstract
Central nervous system lesions were studied by light microscopy in 43 farmed mink, aged 5 months to 2 1/2 years, with spontaneous encephalitozoonosis and showing cataractous eye changes. Lesions were found in the brain and spinal cord of all animals examined but were generally mild and chronic. The lesions were consistent with those previously described in spontaneous encephalitozoonosis in other carnivores. Parasites in parasitophorous vacuoles and free or phagocytosed in necrotic and granulomatous lesions were demonstrated in animals aged 5 months to 1 year. The occurrence of arterial lesions of the polyarteritis nodosa type found in the youngest animals probably indicates fetal infection. In animals aged 1 1/2 and 2 1/2 years active lesions were usually lacking and the changes were characterized by arterial sclerosis, sometimes with aneurysmal formations, small perivascular lympho-plasmacytic cuffings and focal gliosis.
Keywords: Encephalitozoon cuniculi, neuropathology, light microscopy
Sammendrag
De patoanatomiske forandringene i sentralnervesystemet ved spontan encephalitozoonose ble undersøkt hos 43 mink. Dyrene som var i alderen 5 mdr til 2 1/2 år, hadde alle katarakt. Forandringer ble påvist i hjerne og ryggmarg hos alle de undersøkte dyrene, men var generelt moderate og for det meste av kronisk type. Forandringene tilsvarte i store trekk de som er beskrevet tidligere ved spontan encephalitozoonose hos andre rovdyr. Parasitter ble påvist hos mink i alderen 5 mdr til 1 år og forekom enten i parasittofore vakuoler eller fritt eller fagocyttert i nekrotiske og granulomatøse foci. Forekomst av arterieforandringer i form af polyarteritis nodosa tyder på føtal infeksjon. Aktive prosesser manglet for det meste hos dyrene i aldersgruppen 1 1/2–2 1/2 år og forandringene var her karakterisert av arteriosklerose med aneurismedannelser, små perivaskulære lymfo-plasmacyttære infiltrater og fokal gliose.
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