Background <p>Analog radiographic techniques traditionally focus on collimation to enhance diagnostic quality by limiting the field to the area of interest. With digital radiology systems, this study hypothesized that whole-body radiographs are diagnostically equivalent to collimated thoracic radiographs. Conducted at a university teaching hospital from November 2019 to April 2021, the study involved 40 client-owned small-breed dogs and cats presenting with respiratory or cardiovascular complaints. Each animal underwent both whole-body radiographs and collimated thoracic radiographs, and the radiographs were evaluated by three board-certified radiologists and three general practitioners in a blinded, randomized manner, based on a 12-question Likert scale survey.</p> Results <p>Diagnostic assessments of thoracic findings were equivalent between whole-body radiographs and collimated thoracic radiographs, with no significant differences identified by the six reviewers, irrespective of their level of expertise. These findings confirm that whole-body radiographs and collimated thoracic radiographs are diagnostically comparable for identifying thoracic abnormal findings, including cardiomegaly (<i>n</i> = 19), bronchial pattern (<i>n</i> = 12), esophageal dilation (<i>n</i> = 7), alveolar pattern (presumably pneumonia) (<i>n</i> = 6), narrowing of the trachea and bronchi (<i>n</i> = 5), left-sided congestive heart failure (<i>n</i> = 4), pleural effusion (<i>n</i> = 4), rib fractures (<i>n</i> = 2), pulmonary mass/nodule (<i>n</i> = 2), transitional vertebrae (<i>n</i> = 2), intrathoracic lymphadenopathy (<i>n</i> = 1), and hypovolemia (<i>n</i> = 1).</p> Conclusions <p>The study supports whole-body radiographs as a practical alternative to collimated thoracic radiographs for evaluating thoracic abnormal findings in small animals. WBR offers a simpler imaging approach without compromising diagnostic accuracy, providing a flexible and reliable option in clinical practice.</p>