Neurological Newcastle Disease
Newcastle disease is a virus infection that causes respiratory disease, depression, nervous system issues, and diarrhea in chickens. The virus has different strains of different mortality rates and virulence. Chickens are the most at risk but geese and ducks do come down with Newcastle too.
The disease is spread through respiration, coughing, and feces of infected birds. Infected birds eating and drinking from the feeders and waterers will spread the disease and wild birds are also carriers of Newcastle.
Newcastle incubation period is rapid, two to twelve days after respiratory contamination and slower if the birds are ingesting contaminated fecal matter from the feeders and waterers. Young birds are the most susceptible.
Signs of the disease depend on which of the three types infected the bird; respiratory, digestive, or nervous system infection. Gasping for air, coughing, sneezing, or throat rattles are signs for the respiratory strain, tremors, paralysis, twisted necks, birds walking in a circle, spasms, or signs of wing/legs paralysis are signs of the nervous system strain, and watery green diarrhea with the swelling of the head and neck are signs of the digestive strain.
The birds will appear depressed, have poor appetite, and egg production might stop completely. Eggs might have abnormal surface texture, color or shape. Mortality is high with Newcastle disease, as high as 100%. Vaccinated bird might not show the symptoms other than egg production slowing but they will be carriers and shed the live virus while the disease runs it course. Body and head tremors are signs of a vaccination that didn’t quite take but those birds have a mild form of the disease and might recover with some nursing.
Vaccines for turkeys and chickens are available but they serve to produce antibodies, not full immunity, but will lessen the effects of the disease. Mass vaccination can be done through the drinking water but it can be less effective at ensuring all birds received a dose of the weakened or inert virus.
Vaccinating chicks after hatching is good but waiting a few weeks for the maternal antibodies to drop off is more effective. Some chicks will have a reaction to the vaccine due to bacteria colonies in their lungs or digestive system.