Stress and Immune System
Immunglobuline A a promising non-invasive stress parameter
Stress hormones like the glucocorticoids lead to attenuation of immunological functions like the inhibition of immunoglobulin A (IgA). This negative correlation was revealed in stressed dogs with increased salivary cortisol and decreased IgA. Therefore IgA seems to be a marker for animal welfare and stress (Skandakumer et al. 1995). Transfer from home cage to metabolic cage for 3 days resulted in a decrease of faecal IgA in rats during the days after metabolic cage, whereas the faecal corticosterone concentrations remained unchanged during the experiment (Eriksson et al. 2004). These results demonstrated that determination of IgA-secretion is useful in the assessment of potential mid-stressful situations. In horses, particularly in the intestine the IgA-containing cells are more abundant than others like IgM- or IgG-containing cells. Hence determination of faecal IgA seems to be a promising immunological parameter for the assessment of horse welfare.