Three experiments were conducted to evaluate the effects of different supplements (lactoferrin, carotenoids, vitamins E and C) on immune function of adult dogs.
In all three experiments blood was sampled to assess blood traits, lymphocyte proliferative response, lymphocyte subset distribution and immunoglobulin concentrations of plasma. The lactoferrin study further included a faecal microbiology. In the lactoferrin study the differential blood count showed a reduction of neutrophils and an increase of lymphocytes. Proliferation of lymphocytes was variable, only the stimulation index of lymphocytes with ConA increased. CD4+-, CD8+- and CD5+- T-lymphocytes were significantly increased during the treatment phase. Plasma immunoglobulins A and G were not affected by treatment. A reduction of faecal concentrations of E. coli and Cl. perfringens was shown. Carotenoids lutein and lycopene neither increased lymphocyte proliferation nor modulated composition of the lymphocyte population. The concentration of IgG in canine plasma increased only in the first section of the trial in one group. Vitamins E and C did not affect differential blood count or the expression of cell surface markers of lymphocytes. Lymphocyte proliferation numerically increased after treatment with 60mg vitamin E and 30mg vitamin C. For the other two groups, a significant decrease of lymphocyte proliferation was observed. The IgG-concentration increased after administration of vitamins E and C.
In conclusion, lactoferrin, carotenoids, vitamins E and C showed no significant influences on the tested traits of the immune system. The results of the lactoferrin study suggest an effect on cellular immune response and a modulation of canine faecal microflora.
Lactoferrin / Carotenoids / lutein / lycopene / vitamin E / vitamin C / dog / immune system / flow cytometry / lymphocyte