Contagious agalactia in small ruminants

Abstract

Contagious agalactia (CA) is an infectious syndrome caused by several species of mycoplasma and classically characterized by the triad of mammary, joint and eye symptoms, although further symptoms may also appear. CA is the most serious disease of whatever they affect in small dairy ruminants and so there is an urgent need for administrative bodies and farmers to join forces and design serious strategies with the final aim of completely eradicating the disease. CA is endemic in the Mediterranean and certain Asian and African regions, while in America it is described as sporadic. The emergence of CA in a non-infected herd is almost always linked to the introduction of carriers of CA or to contact with infected herds. It normally implies the rapid spread of clinical problems in the herd coinciding with the period of parturitions and the start of lactation. In endemic areas, this disease provokes subclinical or mild clinical symptoms, and the lack of an established, systemized diagnostic procedure implies, that many infected herds pass unnoticed and may act as a permanent source of infection. Enzyme-linked immunosorbent assay (ELISA) techniques are recommended for the detection of antibodies, but the systematic vaccination of herds in endemic areas prevents the use of serology to detect infected herds. Then, culture and polymerase chain reaction (PCR) techniques must be used. In clinical outbreaks, control measures should be directed towards limiting the economic losses of the herd and avoiding the spread of the disease by isolating the infected herd, antibiotic treatment, selective culling, disinfection measures and the classic prevention measures for mastitis (correct functioning and maintenance of milking equipment, the milking routine, teat dipping, etc.). In chronically infected herds, control measures should be directed to restrict disease spread by way of prevention measures for mastitis, detection and culling of animals with lesions, the administration of antimycoplasma drugs to all animals at the end of lactation, adequate management of replacement animals and, perhaps, vaccination. (c) 2006 Elsevier B.V. All rights reserved.