Mink. Brain stem. Aujeszky Disease Virus infection
History: In October 2007, a mink farm had numerous deaths after an acute episode of nervous symptoms. Clinically, mink had ataxia and muscular shrinkages. Necropsy findings: At necropsy animals showed non-specific lesions: congestion and hemorrhages (petechiae) in lungs, heart , liver, serosa and meninges. No macroscopic lesions were observed in the nervous system.
Light microscopic examination: All animals submitted for necropsy showed a very mild non purulent ganglioneuritis and encephalomyelitis. These histological findings were located in the trigeminal ganglia and the brain stem. The lesions were sparse and they consisted of slight gliosis, occasional foci of inflammation, and perivascular cuffing by monocuclear inflammatory cells. Some petechiae were presents too in the nervous tissue nex to a vascular fibrinoid degeneration in small leptomeningeal and parenchymal vessels in the brain and cervical and thoracic segments of the spinal cord.
The picture shows a single positive neuron with brown granular deposits in the cytoplasm, axon and dendrites, after an immune peroxidase technique using an anti-Aujeszky Disease Virus rabbit polyclonal antibody (dilution 1:1500). Antigen-antibodies complexes were detected with a peroxidase-conjugated polymer ( En Vision TM+, Dako Cytomation)
Author: José María Nieto