Spread of equine lungworm (Dictyocaulus arnfieldi) larvae from faeces by Pilobolus fungi.

Between 10 and 25% of the Dictyocaulus arnfieldi larvae excreted in faeces from a naturally infected donkey were harvested as infective stages from faecal cultures by means of Pilobolus fungi. The faeces were collected between 24 and 56 hours after drenching the donor animal with Pilobolus spores and kept at 16 +/- 2 degrees C. Most larvae were collected between the 5th and the 8th day of culturing during which period fructification and sporangium discharge also peaked. The sporangia and the adhering larvae were collected in Petri dishes inserted between the faecal mass and a light source. All recovered larvae were viable. A mean larval length of 368 microns (range 312-440 microns) and width of 14.6 microns (range 12-20 microns) was recorded for the infective stage. The method was found suitable for the recovery of infective stages for experimental purposes. The authors suggest that the Pilobolus mechanism play an important part in the spread of equine lungworm infection under field conditions similar to the situation in bovine lungworm (Dictyocaulus viviparus) infection.