Understanding peste des petits ruminants

This is a viral disease of goats and sheep that can cause great economic losses to small-stock farmers.

The emergency system for transboundary animal and plant pests and diseases livestock unit of the Food and Agriculture Organization of the United Nations (FAO) launched an awareness campaign on peste des petits ruminants (PPR) as an aid to emergency preparedness for this transboundary disease.

PPR may have passed unrecognised for years in some countries because it is frequently confused with other diseases that cause respiratory problems and mortality of small ruminants. Many veterinarians, animal health workers and livestock owners in areas where PPR is absent or recently introduced are not familiar with its clinical and pathological features. The FAO prepared a manual to help them recognise this transboundary disease as it emerges and evolves.

WHAT IS PPR?

According to the World Organisation for Animal Health (WOAH), PPR, also known as ‘goat plague’, is a viral disease of goats and sheep characterised by fever, sores in the mouth, diarrhoea, pneumonia, and sometimes death. It is caused by a morbillivirus in the family of paramyxoviruses that is related to rinderpest, measles and canine distemper. Cattle and several wild ruminants have been infected most often experimentally, but goats and sheep are the usual targets.

The disease occurs in a band that spreads across Africa between the equator and the Sahara, through the Arabian Peninsula, the Middle East, Southwest Asia and India. China first reported the disease in 2007 and it spread into North Africa for the first time in Morocco in 2008.

TRANSMISSION AND SPREAD

The discharges from animals’ eyes, nose and mouth, as well as the loose faeces, contain large amounts of the virus. Fine infective droplets are released into the air from these secretions and excretions, particularly when affected animals cough and sneeze. Other animals inhale the droplets and are likely to become

infected. Although close contact is the most important way of transmitting the disease, it is suspected that infectious materials can also contaminate water, feed troughs and bedding, turning them into additional sources of infection.

These particular hazards are, however, probably fairly short-term since the PPR virus, like its close relative rinderpest, would not be expected to survive for long outside the host. Trade in small ruminants, at markets where animals from different sources are brought into close contact with one another, affords increased opportunities for PPR transmission, as does the development of intensive fattening units.

A MANUAL IS AVAILABLE TO HELP FARMERS RECOGNISE THE DISEASE

When PPR occurs in an area for the first time, it is possible that acute high fever with extreme depression and death occur before any other typical signs have been seen. A more typical picture, however, is that of a fast-spreading syndrome in sheep and/or goats characterised by the sudden onset of depression, discharges from eyes, nose and mouth, abnormal breathing with coughing, diarrhoea and death.

CONTROL MEASURES

According to the WOAH, when the disease appears in a previously unaffected area, the standard control measures consist of quarantine, movement control, sanitary slaughter, and cleaning and disinfection.

There is no medication available to treat the disease, but supportive treatment may decrease mortality. A vaccine is used where the disease is established, and it provides good immunity.

WIKIMEDIA COMMONS Sheep and goats are the usual targets for the peste des petits ruminants virus.