Pulmonary hair embolism in monkeys.

Among 184 rhesus and cynomolgus monkeys treated daily for 28 consecutive days by injection into cephalic or saphenous veins, 14 animals (7.6%) had pulmonary emboli with fragments of skin or hair in arterial thrombi or in giant cell granulomas. 167 monkeys (91%) showed lesions at the site of injection, predominantly bleeding and chronic periphlebitis, whereas particles of skin or hair were rare around the veins (2.2%). 2 or 8 weeks after cessation of treatment no pulmonary lesions were observed and healing at the sites of injection was nearly completed in 11 of 12 monkeys allowed to recover.