ACQUIRED B-LYMPHOCYTE DEFICIENCY AND CHRONIC ENTEROCOLITIS IN A 3-YEAR-OLD QUARTER HORSE

This case report describes a 3-year-old American Quarter Horse with ac quired immunodeficiency. Clinical signs included chronic diarrhea due to Salmonella typhimurium and bacterial pneumonia, Characterization of the immunodeficiency involved in vivo phytohemagglutinin (PHA) intrad ermal testing, in vitro lymphocyte proliferation in response to concan avalin A, immunofluorescence flow cytometry data on blood lymphocytes, serum protein electrophoresis and immunoglobulin (Ig) quantification. A diagnosis of B lymphocyte deficiency with resulting deficiencies in serum IgG, IgA and IgM and a concurrent decrease in T cell function w as made based on these tests, Postmortem examination revealed no evide nce of lymphosarcoma, This case represents a variation of young adult- onset B cell deficiency not previously described in the literature. (C ) 1997 Elsevier Science B,V.