Thelazia - Cattle

Thelazia species:

• Bovine "eyeworm", a spiruroid nematode (white thread-like, 1-2cm long; prevalence approximately 40% in dairy cattle)
• Found in conjunctival sac, inner aspect third eyelid, lachrymal duct
• Indirect life-cycle (intermediate host: nuisance flies, Musca spp.)
• Heavy infections may cause lachrymation and conjunctivitis.