Poultry refers to birds that people keep for their use and generally includes the chicken, turkey, duck, goose, quail, pheasant, pigeon, guinea fowl, pea fowl, ostrich, emu, and rhea. Due to modern systems of management, usually with high poultry densities, these diseases are able to readily spread.n older birds, the disease is called aspergillosis. Species affected: All birds (domestic poultry, pigeons, canary and zoo bird species), animals, humans, and plants are susceptible. Clinical signs: Aspergillosis occurs as an acute disease of young birds and a chronic disease in mature birds.