SARS-CoV-2 and distemper co-infection in a domestic ferret. Case report

Background : Canine distemper virus (CDV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) both infect domestic ferrets, with CDV causing severe and fatal illness, and SARS-CoV-2 presenting with variable clinical signs ranging from subclinical to gastrointestinal and respiratory symptoms. Case description A four-month-old castrated male ferret, housed in a pet store, was presented with anorexia, depression, respiratory signs (eye and nasal discharge) and diarrhea lasting 6 days. The physical examination showed blepharitis , pale mucous membranes and abdominal algesia. Bloodwork showed neutrophilia with a left shift, lymphopenia , hyperbilirubinemia, hypercholesterolemia , increased ALP/GGT and azotemia . The animal was euthanized and lung and tracheal slides were used to diagnose canine distemper by immunohistochemistry and electron microscopy . SARS-CoV-2 diagnostic was performed in pharyngeal and conjunctival swabs as well as lung tissue. These samples were cultured in Vero cells and RNA was analyzed by RT-PCR and high-throughput sequencing. SARS-CoV-2 variant B.1.1.519 was confirmed. Conclusions and clinical relevance This report presents the first documented case of co-infection with SARS-CoV-2 and CDV in a ferret, highlighting the need to include SARS-CoV-2 as a differential diagnosis in ferrets with respiratory disease, especially in cases where multiple pathogens may be involved.