Arterial Worm and Food Impaction

Arterial worms, Elaeophora scheideri, parasitize wild ruminants and are usually associated with facial swelling due to food impactions and occasionally cause damage to teeth or jaw bones.  High worm loads result in reduced blood flow to the face which causes facial paralysis.  This paralysis will cause food to collect in the jaw area. 

The adult nematode typically resides in the carotid arteries of the host where females produce larvae which lodge in the capillaries of the skin on the head.  The larvae are ingested by horseflies taking a blood meal, where they continue to develop and are then transmitted back to a deer where they migrate to the brain and then back to the carotid arteries.