Visceral and subcutaneous acariasis caused by hypopi of Hypodectes propus bulbuci in the cattle egret.

Twenty-one of 24 adult male and female cattle egrets (Bubulcus ibis ibis) collected in Geneva County, Alabama had numerous white cyst-like structures (1,466 microns X 354 microns) found within the loose connective tissues of the skeletal muscles of the inguinal region, beneath the serosa of the proventriculus and in the heart beneath the epicardium (one adult male bird). These were identified as hypopi of Hypodectes (Hypodectoides) propus bulbuci. Histologic sections were prepared from the subcutis, proventriculus and heart. The histopathologic changes consisted of cross sections of mites surrounded by macrophages often containing basophilic or clear intracytoplasmic vacuoles and by plasma cells. A minimal fibrous encapsulation was rarely seen surrounding the mites.