maedi(redirected from Maedan)
a lentivirus that is the causal agent of a type of pneumonia in sheep.
a chronic pneumonia of sheep caused by a lentivirus, which also causes visna when it invades the brain of sheep. In maedi the characteristic features are a prolonged incubation period of more than 2 years, a progressive pneumonia which lasts for about 6 months, and, at the inevitable death, an abnormally high density and heaviness of the lungs. Called also maedi-visna, Graff-Reinert disease, la bouhite, ovine progressive pneumonia and lymphoid interstitial pneumonia.