Preliminary Studies on the Agent of Canine Pharyngo-Laryngo-Tracheitis *

This investigation concerns a study of an upper respiratory disease in dogs which is frequently complicated by pneumonia and encephalitic symptoms. Dr. Leon F. Whitney first reported this syndrome' in 1943 and he described the clinical signs and symptoms, the complications, and the course of the disease. A summary of the initial experimental and pathological studies carried on by workers at the Yale University School of Medicine was also given. The increasing prevalence of this disease has inflicted a serious economic hazard to dog breeders and owners. For this reason, it was considered important to attempt to characterize the etiologic agent. Materials and methods