Respiratory diseases of poultry are some of the most costly problems plaguing today's poultry industry. These respiratory diseases can be devastating to commercial and backyard flocks. Veterinarians in Iowa are occasionally asked to deal with acute resiratory disease outbreaks in one of the many backyard flocks in the state. One disease that must be considered under these circumstances is infectious laryngotracheitis (ILT). Few cases of ILT are diagnosed each year in Iowa. There may be more ILT cases which are incorrectly diagnosed due to the nondescript clinical signs of this disease.