Canine Distemper Virus Beyond Dogs: A Comprehensive Overview From General Pathology To Wildlife Case Studies On Procyonidae

Canine distemper is a highly contagious infectious disease caused by a morbillivirus of the Paramyxoviridae family that leads to significant implications for both companion animals (such as domestic dogs) and wild carnivores. The aim of this thesis is to provide a comprehensive overview of this virus (CDV), addressing its etiology, pathogenesis, clinical manifestations, diagnostic approaches, prevention strategies and available treatments. It begins with an overview of the virus’s virological characteristics, transmission dynamics, and environmental resistance. The pathogenesis of the infection is then examined in detail: CDV initially gains entrance through the respiratory system, then reaches and replicates in lymphoid tissues before disseminating systemically to multiple organs and systems, including the respiratory, gastrointestinal, epithelial and nervous systems, leading to diverse clinical forms. The resulting clinical presentation varies widely, with signs ranging from fever, respiratory and gastrointestinal symptoms to neurological complications in more advanced or complicated cases. Diagnostic approaches, both clinical and laboratory-based, including PCR, serological tests, and immunofluorescence are outlined alongside differential diagnoses, highlighting the relevance and precision of ddPCR. The work also addresses prevention and treatment strategies, focusing on recommended protocols, supportive care, and prognosis. Finally, two clinical case studies are presented based on real cases encountered during my traineeship. The first involves a raccoon admitted to the clinic showing clear systemic signs of canine distemper and due to the severity of the symptoms and poor prognosis, euthanasia was performed. The necropsy revealed lesions consistent with CDV infection, particularly in the intestine, lungs and thoracic cavity, which we then compared with literature. The second case focuses on CDV prevention in a wildlife setting, involving three juvenile coatis (Nasua) placed in quarantine as a precautionary measure due to their high susceptibility to the virus. These cases emphasize both the clinical impact and the ongoing challenges of CDV control, particularly in wildlife conservation contexts.