Concomitant virus-induced gastrointestinal infection in dogs

Many viruses are involved in concomitant infections, which are prevalent in nature. In mixed infections, one or both infectious agents may be increased, reduced, or both may be increased while the other is suppressed. Canine distemper virus (CDV) and Canine parvovirus- 2 (CPV-2) are important causes of gastroenteritis in dogs. Detection of these viruses is challenging since the symptoms are very similar. CDV is a member of the morbillivirus genus in the Paramyxoviridae family, and CPV-2 is a member of the Protoparvovirus genus in the Parvoviridae family; and both predominantly affect puppies and induce gastrointestinal symptoms in dogs. The purpose of this study was to contribute to the differential diagnosis of dogs with gastrointestinal symptoms. A PCR technique with specific primers was used to identify CDV and CPV-2 infections in gastroenteric dogs, and clinical changes in the infected dogs were monitored. The VP2 structural gene of CPV and the nucleocapsid gene of CDV were partially amplified in the study. PCR amplified the partial fragments of the CDV nucleocapsid (287 bp) and CPV-2 VP2 proteins (583 bp) from feces. In total, 3 out of 36 stool samples were positive for CDV and CPV-2 in the same dogs. Gasterointestinal symptoms also supported the diagnosis of concomitant infection with CDV and CPV-2 in these dogs. Dehydration and diarrhea in dogs can be signs of various diseases, such as viral, bacterial, and parasitic infections. After the elimination of non-viral pathogens, CDV and CPV-2 should also be simultaneously investigated to establish what is causing these symptoms. This study demonstrates the potential utility of correct diagnosis for the control of viral infection in dogs, but more research with a broader use of PCR-based detections is needed to assess its impact on differential diagnosis for concomitant infections.