Valeria Regia Sousa

By Valéria Régia F. Sousa, Naiani D. Gasparetto and Arleana B.P.F. Almeida

Canine demodicosis is a common and often severe dermatopathy of dogs. It is caused mainly by Demodex canis, a parasitic mite of the skin of dogs of the genus Demodex, of the order Acarina and family Demodecidae. This study is aimed to review the clinical-pathological presentation of canine demodicosis and the cytokine-mediated immune response to the cutaneous density of the mite. Only dogs with a defective immune response will present the disease, whether localised or generalised. Microscopically, the dermal inflammatory response is similar among dogs. Localised and generalised demodicosis and pyoderma associated with a high cutaneous density of mites are factors associated with aggravation of lesions in both forms of disease presentation. In addition, the participation of cytokines has been investigated in the induction of the immune response in the different forms of the disease. Although different research groups have invested in studies aimed at elucidating the canine demodicosis pathogenesis, there is still insufficient data to understand the important role of the host immune system in triggering clinical signs and the reproductive management is still an effective preventive method for disease perpetuation.

Part of the book: Parasitology and Microbiology Research

By José Nivaldo da Silva, Valéria Régia Franco Sousa, Arleana do Bom Parto Ferreira de Almeida, Adenilda Cristina Honorio-França and Eduardo Luzía França

Visceral leishmaniasis (VL) is a zoonotic parasitic disease caused by Leishmania infantum (L. chagasi) that infects cells of the monocyte-phagocyte system. This work aims to describe the bone marrow parasitism in dogs naturally infected by L. chagasi, and to correlate with serum concentrations of cytokines and antibody level. It evaluated 42 dogs, 21 uninfected and 21 infected by L. infantum, of both sexes and of different ages; dogs were classified into three clinical stages: stage I, mild disease; stage II, moderate disease; and stage III, severe disease. Parasitic index was determined by real-time polymerase chain reaction (PCR) and cytokine serum concentration by flow cytometry. The average parasitic index of infected dogs was 4.59 × 1010 copies/μl. IL-4 and TNF-α concentrations were higher in infected dogs than in the control group. Antibody levels were positively correlated with IL-4 expression. There was a significant positive correlation of IL-6 cytokine levels with the evolution of stages I and III. Antibody levels were positively correlated with IL-4 expression. There was a significant positive correlation of IL-6 cytokine levels with the evolution of stages I and III. However, this cytokine can be used as a marker to distinguish between different clinical stages.

Part of the book: Parasitology and Microbiology Research