title: Maedi-visna and biosecurity.
authors: G T
authors: GT
authors: Edwards
mesh_terms: D000818:Animals; D005260:Female; D015994:Incidence; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000453:epidemiology* / Q000635:transmission; D012756:Sheep; D006113:United Kingdom / Q000453:epidemiology