Acute Respiratory Distress Syndrome in a Dog With Canine Respiratory Coronavirus Infection

To describe the clinical progression of acute respiratory distress syndrome (ARDS) associated with canine respiratory coronavirus and suspected aspiration in a previously healthy young dog.

A 1.5-year-old neutered male Rottweiler was presented for acute respiratory distress. The dog had a productive cough 2 weeks prior that was reported to have improved. While at a boarding facility, the dog developed decreased appetite and lethargy, regurgitated, and became acutely dyspneic. The dog was taken to the veterinarian on site, where thoracic radiographs revealed severe consolidation of the cranioventral lung lobes. The dog was presented to a university referral hospital approximately 12 h after regurgitation with fever, hypotension, hypoglycemia, and leukopenia, and was treated with positive pressure ventilation after failing high-flow oxygen therapy. The dog remained profoundly hypoxemic, developed acute kidney injury, and was euthanized after 24 h. Necropsy revealed diffuse alveolar damage consistent with a diagnosis of ARDS. Bacterial cultures were negative. Real-time polymerase chain reaction results from upper respiratory and fresh lung samples, as well as metagenomics analysis from a lung sample, confirmed the presence of canine respiratory coronavirus.

Canine respiratory coronavirus is primarily associated with mild upper respiratory signs and has not been previously associated with ARDS. Direct pulmonary damage from the virus, decreased mucociliary clearance secondary to viral ciliary damage followed by aspiration, and secondary pulmonary damage from systemic inflammation and coagulation disturbances are all possible in this case. The practical use of metagenomics, an emerging diagnostic screening tool that provides characterization of a virus's entire genome, is also demonstrated here. Metagenomics has not been previously described in small animal clinical medicine and may aid in surveillance of infectious canine respiratory disease and provide better understanding of the role of "milder" pathogens in patients with multifactorial respiratory failure.