If they are already sick it might be too late. See if this helps...
There is no treatment for Newcastle Disease, although treatment with antibiotics to control secondary infections may assist. The virus can remain alive in manure for up to 2 months and in dead carcasses for up to 12 months, however it is easily killed by disinfectants, fumigants and direct sunlight.
Newcastle Disease is a highly contagious viral infection that affects many species of domestic and wild birds to varying degrees. Domestic fowl, turkeys, pigeons and parrots are most susceptible while a mild form of the disease affects ducks, geese, pheasants, quail and guinea fowl. The disease...