Introduction/Causative Agent: Peste des petits ruminants (PPR) is a viral disease similar to rinderpest. It most commonly affects ruminants including sheep and goats. Rinderpest (cattle plague) is a highly fatal viral disease of cattle, which occasionally also affects sheep and goats. Humans are not affected. PPR is found in Africa, the Middle East, and India. Rinderpest is common in India, Africa, the Middle East, Pakistan, and Nepal; it has never been established in the Americas, Australia, or New Zealand. Both diseases are caused by viruses belonging to the family Paramyxoviridae.
Clinical Signs: Most cases of PPR in sheep and goats cause a sudden fever, followed by lethargy, loss of appetite, reduced milk production, nasal and eye discharges, labored/rapid breathing, and diarrhea. The lining of the nose, mouth, and genital tracts are covered with irregular erosions (ulcers). Death occurs 5-10 days after clinical signs begin. In outbreak situations, death rates may reach nearly 100 percent. Rinderpest infections in sheep and goats are usually less severe, but may produce similar signs. Rinderpest in sheep and goats is considered a rare disease.
Disease Transmission: PPR is highly contagious from one animal to another. The disease is often transmitted 1-2 days before any clinical signs are observed. It is found in expelled airborne droplets from the respiratory tract, eye and nose discharges, saliva, feces, urine, and milk. An animal becomes infected when it contacts one of these secretions. Because the virus is not hardy (only surviving 2-3 days in the environment), PPR is less-likely to be transmitted indirectly through environmental contamination. Rinderpest has a similar mode of transmission; however, many sheep and goats become infected, but do not spread the virus to other animals.
Diagnosis: Virus isolation, identification of viral antigen, blood titers, and histopathology can all be used to help detect infections. Samples from a living animal that can be used for testing include lymph node biopsies, nasal and eye secretions, and blood samples. In necropsied animals, samples from internal lymph nodes and the spleen can be used. All tissue samples should be placed on ice when shipped. PPR causes lesions in the intestines and rectum that are often called "zebra stripes" due to areas of congestion.
Treatment: Isolate the affected animals and disinfect contaminated areas with a disinfectant or heat. The virus is rapidly inactivated at 56 degrees Celsius (132 degrees Fahrenheit). Many animals may require supportive care (antibiotics, anti-inflammatory agents) and rehydration. Animals infected with PPR will often die in spite of treatments.
Prevention: In places where these diseases are a problem, vaccination is the best way to prevent infections. When outbreaks do occur, quarantine, slaughter, and decontamination are essential in controlling the problem.