Immunoglobulins (Ig) are proteins produced by the immune system, which help to prevent and fight infectious diseases. Four classes of immunoglobulins are known: IgG, IgM, IgA, and IgE. They have different biochemical structures and are specialized for different tasks. Immunoglobulin A is important in protecting mucosal surfaces of the body, including the respiratory, intestinal and urogenital tract.

There is evidence that IgA deficiency might be inherited. Dog breeds that are affected include German Shepherd Dogs, Chinese Shar Peis, Beagles, Irish Wolf Hounds, and Cocker Spaniels. Affected dogs have lower IgA concentrations in serum and duodenal juice when compared to normal dogs.

Dogs with IgA deficiency may not have any clinical signs at all, but if they do, they typically show clinical signs starting at a young age. These include recurrent infections of the skin, respiratory, gastrointestinal, or urinary tract. Allergies, especially food allergies or atopy are frequently observed. It has been speculated that dogs with IgA deficiency are more prone to intestinal diseases such as inflammatory bowel disease (IBD) or small intestinal bacterial overgrowth (SIBO). Immunoglobuline A deficiency might predispose to an infection with enteropathogenic E. coli bacteria, which can cause severe diarrhea, vomiting and fever.

We recently developed a sampling strategy for determintion of persistently low fecal IgA concentrations. Our aims are to determine the prevalence of IgA deficiency in German Shepherd Dogs and to evaluate potential genetic markers associated with IgA deficiency in German Shepherd Dogs. This project might be helpful identifing carrier dogs allowing for them to be eliminated from future breeding programs.

We are looking for purebred German Shepherd Dogs at least 12 months of age from multi-generational family groups. If you are interested in obtaining further information or participating in our study, please contact Dr. Niels Grützner (ngruetzner@cvm.tamu.edu).