Immunopathological Disorders in Sheep, Goat, Wild Animals, and Laboratory Animals

Immune system protects the body from various infectious agents, toxic and allergic substances. It contains two interrelated responses i.e., innate immune response and acquired immune response. Immunopathological disorders arise when there is defect in the immune system, which are characterized by hypersensitivity, immunodeficiency, and autoimmunity. Hypersensitivity reaction is an exaggerated or elevated immune responses against any antigen and are categorized into four types namely, Type I (immediate or IgE mediated); type II (cytotoxic); type III (immune-complex mediated); and type IV (delayed-type) hypersensitivities. The first three hypersensitivity reactions are the antibody-mediated, while Type IV is T-cell mediated hypersensitivity. Immunodeficiency occurs due to failure or absence of essentials of the immune system such as complement system, lymphocytes, and phagocytes. Autoimmunity is defined as an immune response of the body against self-antigens or own tissues of body. Reactivity against self-antigen can arise either by triggering the receptors directly by autoantigen or through cross-reaction between foreign and self-antigens. In sheep, goat, wild and laboratory animals there are several immunopathological disorders that may prove fatal to animals including acute systemic anaphylaxis, allergic rhinitis, blood transfusion reactions, hemolytic diseases, immune complex mediated glomerulonephritis, transient hypogammaglobulinemia, bluetongue disease, mouse mammary tumor virus infection, simian immunodeficiency virus infection, murine leukemia virus infection, pemphigus foliaceus, autoimmune hemolytic anemia, autoimmune encephalitis etc. Cytokines plays major role in the modulation of immune responses results in development of several immunopathological disorders.