Feline morbillivirus-1 in dogs with respiratory diseases.

Feline morbillivirus-1 (FeMV-1) is a viral pathogen associated with kidney disease in domestic cats and wild felids. We initially identified the FeMV-1 from the lung of a necropsied dog with severe pulmonary disease by the reverse transcription polymerase chain reaction (RT-PCR). Thereafter, we investigated FeMV-1 in nasal and oral swab samples from 73 healthy and 113 dogs with respiratory illnesses. We found polymerase chain reaction (PCR)-positive FeMV-1 from only 14/113 (12.39%) dogs with respiratory disease (p = .001). Of these 14 dogs, six were co-infected with other canine respiratory viruses (6/14; 42.86%). Two independent immunohistochemistry procedures, using antibodies against matrix and phosphoprotein of FeMV-1, confirmed the presence of FeMV-1 in lung tissues of two necropsied dogs (out of a total of 22 dogs, 9.09%) that died from respiratory disease. This finding corresponded to transmission electron microscopy findings that paramyxoviral particles exist in lung epithelia. FeMV-1 antigen localization was also evident in the kidney, lymphoid and brain tissues of two deceased dogs. FeMV-1 was successfully isolated from a necropsied dog and from two living dogs, all with respiratory illnesses, which supports FeMV infection in dogs. The detection of FeMV-1 in dog tissues expands the known tropism of this virus to a non-felid host. Our findings indicate that FeMV-1, alone or in co-infection with other viral pathogens, might contribute to respiratory illness and death in dogs.