Diagnostic value of procalcitonin, C-reactive protein, and leukocyte count in canine ehrlichiosis and canine demodicosis

Canine ehrlichiosis ( E. canis ) is an obligate intracellular organism that resides as a microcolony within a membrane-lined intracellular vacuole (morulae), primarily within monocytes and macrophages of dogs. Canine demodicosis ( D. canis ) is an inflammatory parasitic skin disease associated with the presence of excessive numbers of Demodex mites. We aimed to conduct a comprehensive study on blood procalcitonin (PCT), C-reactive protein (CRP), leukocytes count alterations along with hemato-biochemical, and the clinical observations including clinical history and physical examination in dogs infected with canine ehrlichiosis and canine demodicosis compared to the healthy control group. This work was carried out on 41 dogs constituting 11 apparently healthy dogs used as a control, 19 dogs were infected with canine ehrlichiosis, and 11 dogs were infected with canine demodicosis. The dogs showed lethargy, anorexia, pale mucous membrane, weight loss, lymphadenopathy, and hemorrhagic tendencies in canine ehrlichiosis while in canine demodicosis were pruritus, erythema, papules, pustules, and alopecia. Anemia in both groups with a significant thrombocytopenia in E. canis , insignificant leukocytosis with neutrophilia in E. canis , and with a significant leukocytosis and eosinophilia in D. canis . Insignificant hypoalbuminemia and hyperglobulinemia in E. canis along with a significant hyperglobulinemia in D. canis . There is a significant increase in PCT and CRP levels in both groups along with a significant increase in leukocyte count in the canine demodicosis group compared to the healthy group. We concluded that measuring procalcitonin concentration is more effective than CRP and leucocyte count as an inflammatory biomarker in canine ehrlichiosis and canine demodicosis.