Pulmonary Abnormalities in Dogs with Renal Azotemia

BACKGROUND: Clinical signs associated with respiratory tract disease are regularly encountered in people with kidney failure, and have been anecdotally reported in dogs. OBJECTIVES: To compare clinical signs indicative of pulmonary disease, clinicopathologic findings, radiographic abnormalities, and histologic findings in dogs with acute kidney injury (AKI) or International Renal Interest Society Stage 3 or 4 chronic kidney disease (CKD) to nonazotemic dogs. To determine associations between abnormalities indicative of pulmonary disease and outcome in azotemic dogs. ANIMALS: One hundred sixty-seven pet dogs (54 AKI dogs, 50 CKD dogs, 63 nonazotemic control dogs diagnosed with intracranial disease). METHODS: Retrospective cohort study comparing signalment, clinical signs, clinicopathologic variables, prevalence, and severity of pulmonary radiographic patterns, histopathologic findings, and survival times in AKI, CKD, and control dogs. RESULTS: Clinical signs of pulmonary disease were significantly more common in AKI dogs. Prevalence of an alveolar lung pattern was greater in AKI and CKD dogs. Alveolar mineralization was the most common pulmonary histologic lesion in AKI dogs (6 of 8 dogs), with concurrent alveolar concretions or mineralization of pulmonary vessels or bronchioles noted in 1 dog each; mineralization of lung tissues was not noted in control dogs. Neither clinical signs nor presence of an alveolar pattern were associated with likelihood of survival to discharge or median number of days from discharge until death. CONCLUSIONS AND CLINICAL IMPORTANCE: Abnormalities indicative of pulmonary disease are more common in azotemic dogs than in control dogs; however, prognosis is not associated with presence of clinical or radiographic pulmonary dysfunction.