Immunity, microbiota & immune-related disorders in German shepherd dogs

Sammanfattning: In an epidemiological study based on insurance data we described a breed-specific pattern of diseases in German Shepherd dogs (GSD) and confirmed that this breed is predisposed to immune-related disorders. A prospective study was performed in order to further investigate immunological changes in the GSD using a large number of dogs, 30 bitches and their litters, from the same kennel under well controlled natural conditions. Changes in fecal and serum immunoglobulins were followed from birth to young adult age and possible relationships between these parameters in dams and their offspring were identified. We also described the composition of gut microbiome in dogs and how it changes in different life stages including pregnancy, lactation and growth. The levels of serum IgE, serum IgA and fecal IgA increased from seven weeks of age and were then stabilized at one year of age, there was no relationship in immunoglobulin concentrations between bitches and their 7 weeks old puppies. Dogs with high fecal IgA had a better vaccine response indicating a favorable systemic immune status. We found profound differences in the gut microbiome between mothers and young dogs. Litter mates had a more similar fecal microbiome compared to unrelated dogs. The 7 weeks old puppies were no more similar to the mothers than to unrelated bitches at partum. However, the fecal microbiome of the puppies were significantly more similar to their mothers than to unrelated bitches at 7 weeks postpartum. We observed a change in the relative abundance of different bacteria during lactation, and an increase of diversity from pregnancy to end of lactation. We also found that the diversity of fecal microbiome was affected by living environment but we were unable to demonstrate an effect of pre- and postnatal exposure to the chosen strain of probiotics. Our results provide information to an area within canine microbiology and immunology which is not studied before -this is the first study to describe the gut microbiome as well as immunoglobulins (and their relation to each other) in pregnant and lactating bitches and their offspring. This information is a needed foundation for further research on the relationship between the microbiome at an early age and immune function later in life and of value for the evaluation of interventions.