These two diseases are both caused by a viral infection that affects the respiratory system and can be highly fatal. It is something that we vaccinate our flocks for. Vaccination should take place twice, within 2 weeks of age and again 2 weeks later. This vaccine is added to water and very easy to administer. Two seperate bootles are shipped to cover both vaccinations. 1,000 doses per bottle. We ship vaccines 2nd Day Mon-Wed to avoid week end. Indirect signature required.