Investigation of Serum Cytokine Profiles and Their Association with Disease Severity in Dogs with Naturally Occurring Canine Distemper in Abuja, Federal Capital Territory

Canine distemper virus infection induces a complex immunopathological cascade mediated by cytokines, yet the relationship between serum cytokine profiles and disease severity in naturally infected dogs in Nigeria has not been analytically characterised. This study investigated serum interleukin-6, interleukin-10, tumour necrosis factor-alpha, and interferon-gamma profiles and their association with clinical disease severity in dogs with naturally occurring canine distemper in Abuja, Federal Capital Territory. Sixty dogs confirmed CDV-positive by reverse-transcription PCR were classified into mild, moderate, and severe disease groups based on a validated clinical severity scoring system. Thirty healthy CDV-negative dogs served as controls. Serum cytokines were quantified by canine-specific multiplex enzyme-linked immunosorbent assay. Interleukin-6 and tumour necrosis factor-alpha were significantly elevated in proportion to disease severity, with severe cases showing concentrations six and four times higher than controls respectively. Interleukin-10 was elevated in moderate cases, suggesting an immunomodulatory response, but diminished in severe cases, indicating a failure of regulatory immune mechanisms. Interferon-gamma was elevated in all CDV-positive groups and was not predictive of disease severity. Logistic regression confirmed interleukin-6 as the strongest independent predictor of mortality at day fourteen. These findings provide an empirical cytokine basis for disease severity stratification in canine distemper and suggest interleukin-6 as a priority biomarker for prognostic assessment in clinical settings in the Federal Capital Territory. Keywords: canine distemper, cytokines, interleukin-6, disease severity, Abuja.