Newcastle disease, called Ranikhet in Pakistan, is a fast-spreading virus that can kill a large part of a broiler flock in days. If you see sudden deaths with breathing trouble, green droppings or twisted necks, treat it as an emergency: call your vet, send birds to a lab, close the farm gate, and do not sell or throw out sick and dead birds until you know what it is.
What Newcastle disease is
Newcastle disease is caused by a virus (avian paramyxovirus type 1). Strains differ: mild ones cause little more than a cough, the dangerous ones attack the breathing system, the gut and the nervous system together. The World Organisation for Animal Health lists the virulent form as a disease that must be reported, because it can wipe out whole flocks.
In Pakistan it is one of the most common and costly broiler diseases, and outbreaks are often reported in the cooler months, when the virus survives longer outside the bird. A flock that looked perfect in the morning can be losing birds by evening.
Signs to watch for
Signs usually appear 2 to 12 days after the virus reaches the farm. Not every bird shows every sign.
- Sudden deaths, rising each day, sometimes with few other signs at first.
- Breathing: gasping, coughing, sneezing, a rattling sound at night when the shed is quiet.
- Droppings: greenish, watery, sometimes with white.
- Nervous signs: twisted neck, head drawn back, walking in circles, shaking, one leg or wing paralysed. These often come a few days after the first deaths.
- General: birds dull and sitting, feathers ruffled, feed and water intake falling.
When a vet opens dead birds, bleeding spots in the gut and the stomach lining can point to Newcastle, but only a lab test confirms it.
How it spreads between farms
The virus comes out in the droppings and the breath of sick birds. It sticks to anything that touches them:
- People: shoes, clothes and hands of workers, visitors, vaccinators, catchers and buyers who go from farm to farm.
- Vehicles and crates: broker trucks, feed delivery vehicles, crates and trays from other farms.
- Equipment: feeders, drinkers, egg trays or sacks borrowed from a neighbour.
- Birds: wild birds and pigeons around the shed, and backyard (desi) chickens near the farm.
- Dead birds: carcasses thrown in a canal or field, where dogs, crows and people carry the virus further.
The virus can survive for weeks in litter and dirt, especially in cool weather. This is why one infected farm in an area is often followed by others.
Vaccination basics
Vaccination is the main defence in almost every poultry country. Two types are used:
- Live vaccines, given by eye drop, nose drop, drinking water or spray. They build protection quickly.
- Killed (inactivated) vaccines, given by injection. They give longer protection and are often combined with a live vaccine.
Which vaccines, which days and which route depends on the chick's maternal antibodies, the disease pressure in your area and what the hatchery has already given. Make the plan with your vet; our broiler vaccination schedule guide explains the questions to ask and how to keep the vaccine cold.
Vaccines only work when they are handled right:
- Keep them at 2 to 8°C from shop to shed. A vaccine left in a hot car or bike bag in June may be dead before it reaches the birds.
- Do not use chlorinated water for water vaccines. Your vet can tell you which stabiliser to use.
- Make sure every bird gets its share: enough drinker space, birds slightly thirsty, all vaccine water drunk within about 1 to 2 hours.
- Write down the date, vaccine name, batch number and route for every vaccination.
What to do at the first suspicion
The first hours matter most. Do these in order:
- Call your vet and describe the signs and the number of deaths per day. In Punjab you can also contact the Livestock and Dairy Development department helpline or your nearest government veterinary hospital.
- Send birds for testing. Fresh dead birds and a few sick birds, in a sealed bag, taken by your vet or sent to the district diagnostic lab or a university lab such as UVAS.
- Close the gate. No visitors, no brokers inside, no borrowing or lending equipment. Workers stay on this farm and do not visit other sheds.
- Isolate. If you have more than one shed, use separate workers or visit the sick shed last, with its own shoes.
- Handle the dead properly. Collect them several times a day, keep them in a closed container, and bury them deep with lime or burn them on the farm. Never throw them in a canal or sell them.
- Do not start random medicines. Antibiotics do not kill the virus. Only use what your vet advises for secondary infections. Ask your vet before giving any vaccine to a flock that is already sick.
- Keep records. Daily deaths, feed and water use, and what the vet advised.
If the lab confirms Newcastle, your vet will advise on care for the rest of the batch, selling plans and how to clean the shed. After the batch, clean and disinfect thoroughly and leave the shed empty before the next chicks arrive.
Prevention that works every batch
- A strong farm gate: one entry, foot dip with fresh disinfectant, farm shoes and clothes for anyone entering.
- No contact with backyard chickens, pigeons or birds from other farms.
- Clean crates and vehicles, and keep broker trucks away from the shed door.
- All in, all out: one age of birds on the farm, full cleaning and rest time between batches.
- A vaccination plan made with your vet and followed exactly.
For gate rules, visitors and dead bird disposal, read bird flu, H9 and farm biosecurity. To understand what normal and worrying death levels look like by week, see reducing broiler mortality.
Recording daily deaths and every vaccination in Poultry Curve gives your vet a clear picture in minutes, instead of you trying to remember. If you want to talk through what you see before the vet arrives, Helper can help you organise the facts, but the diagnosis always comes from a vet and a lab.