Background: There is a lack of consensus regarding which markers of disease resolution to prioritise when assessing treatment response in client-owned dogs with aspiration-induced lung injury. This study describes the change over time and the agreement between the clinical markers used to determine disease resolution. Methods: Physical examination (PE), owner-reported clinical signs (CS-O), thoracic radiographs (TXR) scores and C-reactive protein (CRP) concentrations were determined at enrolment, after 24, 48 and 72 hours, and after 7, 14 and 28 days. Results: PE scores were significantly improved at 48 hours, while CRP initially increased (24 hours) and then decreased (48 hours). PE, CS-O and CRP significantly improved earlier (7 days) than TXR (14 days). The median number of days to marker normalisation was 7, 9 and 14 for PE, CRP and CS-O, respectively. Marker agreement was excellent/very good at enrolment and fair/poor during disease recovery. Limitations: Analysis did not control for differences aetiology of aspiration or the lack of standardisation in treatment approach. Conclusions: PE was the earliest and most consistent marker indicating disease resolution. Serial CRP monitoring (72 hours) may provide an objective marker of early treatment response. Alongside PE normalisation, improvement in CS-O, CRP and TRX may assist in determining disease resolution and guide treatments, including limiting antibiotic exposure in dogs with aspiration-induced lung injury.