Possible immunodeficiency in related rottweiler dogs

A litter of eight rottweiler pups is described in which two dogs died before the age of six months from systemic inflammatory disease, and two further pups developed inflammatory skin disease. All seven pups tested had a markedly low serum immunoglobulin A (IgA) concentration (< 0.1 mg/ml) and six of these dogs also had subnormal serum IgG (< 0.1 to 6.4 mg/ml). Tissues taken from three diseased pups were examined immunohistochemically using a number of lymphoid markers. Secondary lymphoid tissues had a paucity of CD3+ T lymphocytes, although T cells were found within some inflammatory foci. B-lymphocyte follicles were present within lymphoid tissues, but there were irregularities of plasma cell development and a lack of plasma cells of all classes within mucosal and cutaneous sites. Inflammatory lesions were dominated by macrophages expressing class II molecules of the major histocompatibility complex. Serum immunoglobulins were also investigated in eight related, clinically normal adult dogs. Five of these dogs, from two separate breeding lines, had subnormal serum IgA (< 0.1 to 0.15 mg/ml). The spectrum of disease within the affected litter may be consistent with an underlying inherited immunological defect, and the observed immunological abnormalities suggest a more complex disorder than simple IgA deficiency.