PESTE DES PETITS RUMINANTS (PPR) IN GOATS AND SHEEP. PREVENTION AND CONTROL MEASURES ACCORDING TO THE GUIDELINES OF THE DEPARTMENT OF LIVESTOCK PRODUCTION AND ANIMAL HEALTH

Peste des Petits Ruminants (PPR) in goats and sheep is one of the most dangerous infectious diseases affecting these animals, causing high mortality rates and serious economic losses for farmers. The disease spreads rapidly and can cause severe outbreaks if not properly controlled, directly impacting productivity and herd safety.
In this article, Fivevet shares essential information about PPR, along with response and prevention measures in accordance with the guidelines of the Department of Livestock Production and Animal Health, to help farmers proactively protect their goat and sheep herds. I. Peste des Petits Ruminants (PPR)
Peste des Petits Ruminants (PPR) in goats and sheep is a dangerous infectious disease with transboundary spread potential, caused by the PPR virus. This pathogen belongs to the genus Morbillivirus, family Paramyxoviridae, and is closely related to the human measles virus and the virus causing rinderpest in cattle. The PPR virus consists of six structural proteins (N, P, L, M, F, H) and two non-structural proteins (C, V). Based on partial sequences of the N and F genes, PPR virus strains are classified into four lineages (I, II, III, and IV); notably, strains currently circulating in Asia all belong to lineage IV.
PPR primarily affects small ruminants such as goats and sheep, with goats generally being more susceptible. The disease may also occur in camels. Cattle and buffalo can be infected with the virus but do not show clinical signs and do not shed the virus; therefore, they do not play a role in disease transmission. Importantly, the PPR virus does not infect humans (WOAH, 2022).
PPR is a notifiable disease listed by the World Organisation for Animal Health (WOAH). Furthermore, within the framework of the Global Framework for the Progressive Control of Transboundary Animal Diseases (GF-TADs), PPR is classified as a priority disease for control due to its rapid spread and significant impact on the livestock sector.
II. Epidemiological characteristics
Healthy animals can become infected through direct or indirect contact with infected livestock. The virus primarily enters the body via the respiratory and digestive tracts through contaminated air, feed, drinking water, farming equipment (feed troughs, transport vehicles, etc.), or through contact with feces, urine, milk, and aborted materials from infected animals, all of which contain high viral loads.
Morbidity and mortality rates vary depending on the virulence of the virus strain, susceptible species, age, breed, immune status, and husbandry conditions. In many outbreaks, morbidity can reach 90–100%, while mortality typically ranges from 50–90%. In acute cases, the mortality rate may reach up to 90% of the entire herd.
The disease shows seasonal patterns, with outbreaks occurring more frequently during the rainy season and periods of dry weather. In addition, the concentration, trading, and transportation of livestock significantly increase the risk of disease spread and outbreak occurrence.
PPR virus is mainly transmitted through aerosol droplets, nasal and oral secretions, or contact with body fluids, feces, urine, and contaminated farming environments. The virus can survive for long periods in chilled or frozen tissues but is easily inactivated under normal environmental conditions and by physical and chemical agents.
III. Clinical signs of Peste des Petits Ruminants (PPR) in goats and sheep
The incubation period averages 4–5 days and may range from 3 to 14 days. In the acute stage, affected animals develop a high fever of 40–41°C lasting 3–5 days, accompanied by depression, anorexia, and dry nasal mucosa.
As the disease progresses, animals show lacrimation, nasal discharge, and oral mucosal secretions. Initially, the discharges are serous but later become mucopurulent, often accompanied by excessive salivation. Ulcerative and erosive lesions of the oral mucosa may undergo necrosis; in severe cases, fibrin deposits can be observed on the tongue.
Subsequently, animals commonly develop diarrhea, coughing, dyspnea, weight loss, and progressive emaciation. In severe forms, body temperature may drop rapidly, and death can occur within 5–10 days after the onset of clinical signs. Bronchopneumonia, manifested by severe coughing, usually appears in the late stage of the disease. In pregnant females, PPR may cause abortion. Morbidity and mortality rates in young goats and sheep are consistently higher than in adults.
Some mild cases may recover after 10–15 days and subsequently develop lifelong immunity. The severity of disease, as well as morbidity and mortality rates, depends on the virulence of the virus strain, environmental conditions, and the immune status of the host. IV. Pathological lesions of Peste des Petits Ruminants (PPR) in goats and sheep
4.1. Gross lesions
The disease causes hemorrhage and necrosis of the gastrointestinal mucosa, extending from the oral mucosa down to the ileocecal valve. Lesions are usually more severe in the large intestine, particularly at the ileocecal valve and the cecocolic–rectal junction.
In the large intestine, lesions form longitudinal congested streaks along the mucosal folds, giving rise to the characteristic “zebra stripe” appearance, which is a typical gross lesion of PPR. Intestinal impaction, necrosis of Peyer’s patches, and enlargement of lymph nodes may also be observed.
Other organs commonly show pathological changes, including hemorrhage and necrosis of the liver and spleen, as well as pulmonary edema, interstitial pneumonia, and pulmonary hemorrhage.  4.2. Microscopic lesions
Histopathological examination reveals the presence of multinucleated giant cells and intracytoplasmic inclusion bodies. These cells are commonly observed in the pulmonary epithelium, bronchial epithelium, alveoli, and colonic epithelium.
Hepatocytes show degenerative changes with cytoplasmic vacuolation, accompanied by infiltration of eosinophils and lymphocytes in the portal areas.
The lungs exhibit marked pathological changes, including congestion, petechial hemorrhages, interstitial pneumonia, and increased proliferation of fibroblasts within the pulmonary tissue.
V. Diagnosis of Peste des Petits Ruminants (PPR) in goats and sheep
5.1. Clinical diagnosis
When animals show signs such as fever, ocular–nasal–oral discharge, diarrhea, and oral ulceration, samples should be collected and submitted to an authorized laboratory for testing.
5.2. Laboratory diagnosis
a. Sample collection
- Secretion samples: Use sterile swabs to collect ocular or nasal discharges, or samples from lesions in the oral cavity. Place the swabs in tubes containing PBS supplemented with antibiotics.
- Blood samples: Collect approximately 5 mL of blood from febrile animals suspected of infection. Transfer into tubes containing anticoagulant and gently mix.
- Serum samples: Collect about 5 mL of blood from the jugular vein. After collection, withdraw the plunger slightly to create an air space, label both the plunger and tube, and place the tube at a 45° angle. Allow the blood to clot for 1–2 hours at room temperature, protected from direct sunlight.
- Tissue samples: Collected during necropsy, including lymph nodes (pulmonary and mesenteric), spleen, lung tissue, and intestinal mucosa (ileum and cecum). Each sample should weigh approximately 5–10 g.
b. Sample preservation
Samples must be properly packaged and stored in insulated containers at 2–8°C and transported to the laboratory within 24 hours.
If testing cannot be performed immediately, samples should be stored at −80°C.
c. Laboratory diagnostic methods
- Virus detection tests:
+ RT-PCR or real-time RT-PCR (targeting the N or F gene; high sensitivity)
+ Immunocapture ELISA (IC-ELISA)
+ Rapid field tests (LFD)
- Serological tests:
+ Competitive ELISA (c-ELISA)
+ Virus neutralization test (VNT)
- Virus isolation in cell culture.
- Gene sequencing (partial N or F gene sequencing or whole-genome sequencing) for virus lineage identification.
Positive laboratory results should be interpreted in combination with epidemiological data and clinical signs to accurately confirm and define an outbreak.
VI. Control and response measures for Peste des Petits Ruminants (PPR) in goats and sheep
- Collect samples and submit them to an authorized diagnostic laboratory when goat or sheep herds show signs suspected of PPR infection.
- Upon laboratory confirmation of PPR infection:
+ Isolate the entire infected herd and suspend the movement of goats and sheep within the outbreak area and the buffer zone with a radius of ≥3 km from the outbreak site.
+ Officially declare the outbreak and implement disease control measures in accordance with the Law on Animal Health and relevant guiding regulations.
+ Cull and safely dispose of all infected animals, animals showing clinical signs, and animals that have died from PPR to prevent further spread.
+ Conduct emergency vaccination for all healthy goats and sheep eligible for vaccination within the affected commune and neighboring communes.
+ Carry out thorough cleaning and disinfection:
Once daily for the first 7 days at infected households and high-risk areas.
Then three times per week for the following two weeks.
+ Report the results of the implementation of disease prevention and control measures to the Department of Livestock Production and Animal Health in accordance with regulations.
VII. Prevention of Peste des Petits Ruminants (PPR) in goats and sheep
a. Biosecurity and good farming practices
Strictly apply biosecurity measures and good husbandry practices to reduce the risk of PPR transmission:
- Quarantine newly introduced goats and sheep for 21 days before mixing them with the herd.
- Regularly disinfect housing, feeding troughs, and farming equipment using approved disinfectants.
- Properly manage waste and water sources to ensure they remain clean and uncontaminated.
- Restrict access of people and vehicles to livestock areas to minimize the introduction of pathogens from outside.
- Carry out routine cleaning, disinfection, and sanitation at farms, markets, trading points, and slaughter facilities for goats and sheep using lime powder or approved veterinary disinfectants in accordance with regulations.
- Use appropriate supportive products to enhance the immune resistance of livestock.
b. Vaccination
The World Organisation for Animal Health (WOAH) recommends the use of live attenuated vaccines based on the Nigeria/75/1 or Seungri/96 strains, which provide protective immunity for at least 3 years after vaccination.
- Target animals: Goats and sheep aged 3 months and older.
- Vaccination schedule:
+ High-risk areas: Annual mass vaccination of the entire herd.
+ Low-risk/safe areas: Vaccination every 2–3 years.
In addition to PPR vaccination, full vaccination against other important diseases of small ruminants - such as foot-and-mouth disease, lumpy skin disease, and hemorrhagic septicemia - is recommended to strengthen overall immunity and minimize the risk of disease outbreaks.