Oxyspirura mansoni

Oxyspirura mansoni, referred to often as the eyeworm, is a parasitic roundworm that infects the eyes of birds. They live on the surface of and/or behind the eyeball in the lacrimal duct and its associated glands. The disease caused by Oxyspirura worms is called oxyspiruriasis or oxypirurosis.

Distribution: O. mansoni are frequently found in tropical and subtropical regions worldwide.

Identification of eyeworm eggs
O. mansoni are small (approximately 15mm long, ranging from 8 to 22 mm) white worms that are covered in a cuticle. They have a rounded anterior and pointed posterior.

Eye Worm Life Cycle: O. mansoni have an indirect life cycle and use cockroaches as intermediate hosts. Chickens become infected by eating contaminated cockroaches. After digestion infective larvae are released in the bird's gut. They migrate along the esophagus the pharynx and the mouth to the lacrimal duct and the eyes. Once there, they complete development to adult worms and start producing eggs. The prepatent period (time between infection and first eggs shed) is 4 to 5 weeks.



  • Order: Spirurida
  • Family: Thelaziidae
  • Genus: Oxyspirura


  • wild birds
  • poultry
  • cockroaches