Evaluation of infection with N protein-specific Immunoglobulin M and G in naturally occurring distemper in dogs

In dogs, canine distemper has a worldwide distribution with high morbidity/mortality, despite the widespread usage of vaccines and has no specific treatment. In susceptible animals with the canine distemper virus, respiratory, gastrointestinal and nervous system disorders, immunosuppression and cutaneous lesions can also be seen. Especially puppies and unvaccinated dogs are prone to get the viral infection. IgM and IgG antibodies constitute the major component of the natural antibodies produced during the primary and secondary antibody response that have long been recognised to inhibit viral infections. In the present study, the presence of the viral N protein-specific IgM and IgG was investigated by indirect ELISA in naturally infected dogs. Moreover, the rate of outbreaks in naturally infected dogs was shown by the detection of new and re-infections. In the Western Mediterranean region, blood serum samples were collected from 50 unvaccinated dogs for the mentioned infection between 2015 and 2017. At 0-12 months, in the dogs with clinical symptoms, the indirect ELISA detected 4% acute, 54% early convalescent, 40% late convalescent and 2% no infections phases. The clinical manifestations were studied in four main groups follow as: respiratory, gastrointestinal, nervous and cutaneous symptoms. The evaluation showed that the canine distemper virus N protein-specific antibodies detection by the indirect ELISA is quick and safe in naturally infected dogs. In conclusion, the method is very useful for the pre-diagnosis of the disease when evaluated together with the clinical symptoms. It helps to distinguish acute and convalescent (early/late) phases. Distinguishing these phases of infection is important for monitoring the spread of the outbreaks and identifying the risk of severe forms of canine distemper.