II. Retrospective Radiographic Analysis of Pulmonary Disease in Rural and Urban Dogs

Abstract

Chest radiographs made on 1,007 canine subjects at the University of Pennsylvania Veterinary Hospital between 1965 and 1968 were reviewed to determine whether a relationship between nonspecific chronic canine pulmonary disease and the urban environment could be demonstrated. Radiographs were graded for evidence of chronic pulmonary changes without prior knowledge of the animal’s age or residence. The environment was divided into urban and rural segments based upon the concentration of industrialization in the Philadelphia area and available atmospheric pollution data. No significant differences were noted in the urban-rural distribution of absent, moderate, and severe changes in younger dogs. In middle-aged and older dogs, however, significant differences appeared in the distribution of changes between environmental groups.