Studies on the immunomodulatory effects of bovine colostrum in healthy dogs and dogs with atopic dermatitis

The aim of the study was to investigate the immunological effects of bovine colostrum in healthy dogs and dogs with AD. In the first study part, 10 healthy beagles were fed a basic diet without or with bovine colostrum of quality 1 (IgG concentration = 25 %) or quality 2 (IgG concentration = 30 %) for 4 weeks each, using a cross-over experimental design. The dietary inclusion level of the bovine colostrum was 0.2 % in dry matter. Two-week wash-out periods were considered between the feeding periods. At the end of each feeding period, blood and fecal samples were collected for several immunological analyses (phenotyping of immune cells, proliferation and phagocytosis assays, measurements of Igs and acute phase proteins). In the second study part, 20 client-owned dogs with AD were included in a placebo-controlled, double-blind study. After an adaptation period of 14 days, the dogs were divided into a placebo or bovine colostrum group. For this, either cellulose (placebo) or bovine colostrum (IgG concentration = 30 %) was supplemented to the regular diets of the dogs at a concentration of 0.2 % in dry matter for 4 weeks. A follow-up period of additional 4 weeks was subsequently considered, where the regular food was offered without the supplements. Blood and fecal samples were collected on day 14, 42 and 70 of the study to measure the same immunological parameters as in the healthy beagle dogs, with the exception of a phenotyping of blood lymphocytes. In addition, skin lesions and the pruritus scores of the dogs were assessed on these evaluation days, and the owners were asked to fill in questionnaires on the QoL and QoC of their dogs. The results demonstrated no immunological effects of bovine colostrum in the healthy and diseased dogs. In the dogs with AD, there were also no differences in the examination of skin lesions, the rating of pruritus, or in the assessment of the QoL. For the QoC, only a minor impact of the dietary treatment could be detected, with a slight improvement of the QoC in the dogs of the bovine colostrum group on day 70 compared to day 14, as reported by the owners. Neither the healthy dogs nor the atopic dogs showed any side effects, why an inclusion of 0.2 % bovine colostrum on a dietary dry matter basis can be considered to be well tolerated in dogs. Future studies could evaluate a potential immunomodulatory impact of higher dietary doses or a different composition of bovine colostrum. Moreover, the measurement of additional immunological parameters might provide further insights into the effects of bovine colostrum in the healthy and diseased organism.