Objective—To establish an objective method of determining proventricular diameter in psittacine birds by assessment of lateral whole-body radiographic views.
Design—Retrospective case-control study.
Animals—100 parrots with no signs of gastric disease and 19 parrots with signs of gastric disease.
Procedures—Measurements were obtained for the following variables: proventricular diameter at the level of the junction between the last thoracic vertebra and synsacrum, maximum distance between the dorsal serosa of the proximal aspect of the proventriculus and dorsal border of the sternum, maximum coelomic cavity height at the level of the proximal aspect of the proventriculus, and maximum dorsoventral height of the keel of the sternum. The ratio of proventricular diameter to each of those measurements was calculated and compared among species within the group without signs of gastric disease and between the gastric and nongastric disease groups.
Results—No significant differences were seen among species of parrots without signs of gastric disease for any ratio, but there were significant differences between parrots with gastric signs and those without gastric signs for all ratios. Only the proventricular diameterto-maximum dorsoventral height of the keel of the sternum ratio had no numeric overlap between groups. Sensitivity and specificity of the ratio for detection of proventricular enlargement were both 100%. Six causes associated with proventricular enlargement were identified.
Conclusions and Clinical Relevance—Evaluation of the proventricular diameter-to-keel height ratio is a new method for evaluating proventricular size in psittacines. Ratio values < 0.48 indicate normal proventricular diameter and the absence of proventricular disease.