Immunodeficiency manifested by oral candidiasis and bacterial septicemia in foals.

: Oral candidiasis and bacterial septicemia were diagnosed in 8 foals that had laboratory and/or pathologic evidence of immunodeficiency. Two foals suffered solely from complete failure of passive transfer of colostal immunoglobulins. Six foals had evidence of immune defects but did not meet the criteria for diagnosis of any of the currently recognized primary equine immunodeficiency syndromes. All six of these foals died or were euthanatized due to bacterial infections. One foal with failure of passive transfer recovered and the other died of a mesenteric torsion before the effect of treatment could be evaluated.