1. Causes of Newcastle Disease
Newcastle disease, or avian pneumoencephalitis, is caused by the Newcastle virus, which belongs to the Paramyxovirus group. This RNA virus can affect all types of poultry, including ducks, geese, and various chicken breeds such as domestic, industrial and fighting chickens.
2. Symptoms of Newcastle Disease in Chickens
The incubation period of Newcastle disease is 3-5 days, though as short as 2 days or extend beyond a week in some cases. The disease progresses through three main stages: Very acute, acute, and chronic.
2.1. Very acute Stage
- Chickens are depressed, ruffled feathers.
- Rapid spread with a 100% mortality rate within a few hours.
- Coughing, rapid breathing, bloody feces, twisted neck.
- Swollen head, cyanotic comb and wattles.
- Neurological symptoms, unsteady walking, pecking at feed inaccurately.
- Reduced egg production, soft eggshells.
- High fever of 42.5 – 43°C.
2.2. Acute Stage
- Sudden outbreak, rapid spread.
- Reduced egg production, decreased feed intake, lower egg quality.
- Neurological symptoms, twisted neck, circling, convulsions, inaccurate pecking at feed.
- High fever of 42.5 – 43°C.
- Green diarrhea, coughing, high mortality rate up to 100%.
2.3. Chronic Stage
- Due to cerebellar damage, chickens exhibit abnormal behavior, death from starvation, inaccurate pecking at feed.
- Reduced egg production in laying hens.
- Disease duration ranges from a few days to several weeks.
- Watery eyes, depression.
3. Pathological Lesions in Chickens with Newcastle Disease
Upon necropsy, many typical lesions of Newcastle disease can be observed:
- Very acute Stage: Lesions are not clear, only hemorrhages in the pericardium and respiratory tract mucosa.
- Acute Stage: Emaciated chickens, cyanotic comb and wattles. Nasal and oral cavities contain a lot of cloudy mucus. Hemorrhages and inflammation in the mucosa of the mouth, pharynx, larynx, and trachea covered with fibrin pseudomembrane.
- Digestive Tract: Hemorrhages at the tip of the glandular stomach mucosa. Hemorrhages under the keratin layer of the muscular stomach. Hemorrhages and catarrhal inflammation in the small intestine mucosa. Ulceration in lymph nodes at the cecal junction.
- Liver: Some pale-yellow necrotic spots.
- Oviduct and Ovary: Streaked and clustered hemorrhages.
- Serous Membranes: Hemorrhages in the pericardium, thoracic cavity, and sternum surface.
- Brain: Hemorrhagic inflammation.
4. Diagnosis of Newcastle Disease in Chickens
Diagnosing Newcastle disease is crucial for determining appropriate prevention and treatment measures. Diagnosis methods include clinical symptoms and characteristic pathological lesions.
5. Prevention of Newcastle Disease in Chickens
5.1. Farm Hygiene
Regular cleaning, disinfection, and sterilization of barns and equipment using lime powder or specialized disinfectants such as
Five-Iodine,
Five-BGF,
Five-B.K.G,
Five-Perkon 3S, etc.
Mix litter with
Five-Prozyme probiotics to absorb moisture, reduce toxic gases released from manure decomposition, and inhibit pathogens.
Regularly clean barns, wash feeding and drinking troughs, and poultry-specific equipment.
Strictly control farm entry and prevent poultry from contacting pathogens. Quarantine newly acquired chickens for 10-14 days for monitoring. Do not house other poultry species with chickens.
5.2. Prevention with Newcastle Vaccine
- Using the Newcastle vaccine for chickens is the most effective prevention method. Use products such as
Five-LaSota,
Five-LaSota HR,
Five-ND.IB,
Five-Newcastle G7,
Five-Newcastle,
Five-ND.IB.AI (H9N2),
Five-ND.IB.EDS to vaccinate farm chickens, selecting the appropriate vaccine based on the farm's epidemiology, scale, and chicken age to achieve effective Newcastle disease prevention.
- Fully vaccinate against other diseases to prevent Gumboro, fowlpox, avian flu, IB, ITL, Coryza, etc.
- Regular preventive treatment with antibiotics for gastrointestinal and respiratory diseases, along with supportive drugs to enhance resistance, improve digestion, detoxification, and reduce stress.
6. Treatment of Newcastle Disease in Chickens
When a flock of chickens tests positive for Newcastle disease, interventions should be made to reduce losses according to the following steps:
Step 1: Determine the age of the affected chickens, the season of occurrence, severity, and disease stage to decide the treatment approach:
* If chickens have not been vaccinated against Newcastle disease during the chick and grower stages, use the Five-ND.IB vaccine immediately, administered via eye drops or orally at double the dose.
* If grower and broiler chickens (over 2 months old) have been vaccinated with basic vaccines such as
Five-LaSota and
Five-ND.IB, use the
Five-Newcastle vaccine injected directly into the outbreak.
* For flocks with poor condition:
- Use Newcastle antibody injections.
- When the chickens' health improves, re-administer the
Five-LaSota or
Five-ND.IB vaccine.
Step 2: Use products that reduce fever, detoxify the body, and enhance resistance such as
Five-Para.C,
Five-Lyte Oral,
Beta-Glucan.C,
Five-Bogama,
Five-Orgamin, etc.
Step 3: Use antibiotics to prevent secondary infections:
Five-Ampicon,
Five-Amoxcin super,
Five-AmoxClav,
Five-Sultrim,
Five-Anticoc,
Five-Coryza,
Five-Doxyl 750, etc.