EN
Small ruminant lentiviruses (SRLV), that is, caprine arthritis-encephalitis virus (CAEV) of goats and maedi-visna virus (MVV) of sheep, are two closely related retroviruses that cause chronic inflammatory disease. SRLV infections are distributed throughout most countries of the world, particularly in Europe, and are characterized by an insidious onset and slow progression. Infection is usually diagnosed by serological testing. The fact that caprine and ovine lentivirus sequences are interspersed within both species supports the existence of cross-species transmission. This paper brings together current information regarding possible impact of genetic diversity and cross-species infection on the effectiveness of serological tests and identifies future use of vaccination.