Chemically-induced delayed cutaneous hypersensitivity in dogs infected with Demodex canis

Demodex canis 감염이 화학적으로 유발된 지연형 피부과민증에 미치는 영향

To observe the effect of Demodex canis infection on the cellular immune response and hematological profile, 8 Doberman pinschers experimentally infected with D cains and 4 uninfected control dogs were sensitized with 2, 4-dinitro-chlorobenzene(DNCB) on the skin and were challenged with DNCB 14 days after the initial sensitization to elicit allergic contact dermatitis. Histological and hematological changes of these dogs were then observed. Macroscopic changes of skin challenged with DNCB in D canis-infected dogs included significantly reduced area of allergic reaction(p<0.05) than in uninfected control group. Infiltration of inflammatory cells in the D canis-infected group was also significantly reduced(p<0.05) than in the uninfected control group. These changes indicated that the cell-mediated immune response of the animals was suppressed by the infection with D canis. Total white blood cell count in dogs infected with D canis was increased when dogs were sensitized with DNCB (p<0.01). The result appeared to be caused by stress due to D canis infection, secondary bacterial infection and decreased efficacy of general body defense system. Blood eosionophils were increased in D canis-infected dogs which appreared to be caused by the allergic contact dermatitis. Blood chemistry analysis revealed that total protein and globulin were increased(p<0.05), while albumin level was decreased. This result appeared to be caused by secondary bacterial infection.