Demodicosis is a parasitic disease of domestic and wild animals and humans. The mite, Demodex canis, is the causative agent of 2 inflammatory skin disease in dogs. Canine demodicosis is a example of immunosuppression associated with a defect in T cells and production of serum suppressor factor. Two forms of demodicosis, the localized and generalized, are recognized. Immunoglobulin quantitation, the measurement of total globulin fractions, determination of hematalogical and serum biochemical values in dogs with skin problems is the purpose of this study. Serum samples were collected from 12 healthy dogs, 15 dogs with non-infections and non-parasitic dermatitis, 6 dogs with localized and 12 dogs with generalized demodicosis. Total serum IgG and IgM were measured by single radial immunodiffusion using rabbit antiserum to canine IgG and monoclonal antibody to canine μ-chains. Standard hematological and serum biochemical tests, serum electrophoresis on cellulose acetate paper have been used. Mean total serum IgG concentrations in healthy dogs, and in the dogs with dermatitis, localized and generalized demodicosis were 9.25 mg/ml, 13.24 mg/ml, 12.33 mg/ml and 16.8 mg/ml, respectively. Mean total serum IgM concentrations were 2.67 mg/ml, 2.08 mg/ml, 2.86 mg/ml and 2.61 mg/ml in the four groups. The lower lymphocytes and higher neutrophils values in dogs with generalized demodicosis were found. Besides, our results showed, that the Demodex canis skin infection of dogs is characterized by an elevated level of the proteins in the β region of serum electrophoresis patterns, where immunosuppressor factor may be located. An additional data in facilitating the understanding of the immunopathogenesis of the skin diseases in dogs were obtained.