Pulmonary contusion in dogs and cats

Pulmonary contusion in dogs and cats is caused by blunt trauma and is a common finding in animals that have been hit by cars. Hemorrhage into the interstitium and alveoli occurs, usually in localized regions of the lungs. Pneumothorax, hemothorax, and rib fractures can also occur. Thoracic involvement should be considered in any animal with evidence of severe trauma, even if there are no external signs of trauma in that region of the body.
Historical or physical examination evidence of trauma is generally present in dogs and cats with pulmonary contusions. Although increased respiratory efforts may be noted, pneumothorax, pain from rib fractures, cardiovascular shock, or neurologic damage may also affect breathing patterns. Crackles may be auscultated over the contused areas.

Pulmonary contusions are diagnosed on the basis of evidence of trauma and the finding of typical radiographic signs, although the latter may not be evident until almost a day after trauma. Large localized ares of alveolar and interstitial opacities are seen in dogs and cats with pulmonary contusions.

Dogs and cats with pulmonary contusions receive treatment for trauma-related problems as indicated by clinical signs. The contusions themselves are not treated directly. Although antibiotics have been recommended to prevent infection in damaged tissue, they are more effectively used to treat animals that have developed actual signs of infection. It is recommended that radiographs be obtained periodically to monitor the resolution of abnormalities. The frequency of this depends on the severity of the initial abnormalities and the clinical signs. Complications that may arise in animals with pulmonary contusions include a secondary bacterial infection, abscesses, lung lobe consolidation, and cavity lesions.

The prognosis for recovery from pulmonary contusions is excellent, provided that the animal's condition can be stabilized after the trauma. The possible complications of contusions noted earlier are rare.