Click Here to Order Online!
While very rare, cases of Thelazia lacrymalis commonly known as the Eye Worm do occur, most often in the summer months. They are often noticed while a horse is being examined for another issue as many horses infected with Thelazia show no clinical symptoms whatsoever, other than the presence of these tiny worms in their eyes.
- 28 – 38% of horses in the United States are infected and most show no outward signs.
- Spirurid nematode found on the surface of the eyeball, under the eyelids and nictitating membrane (third eyelid), under the conjunctiva and in the tear ducts.
- Musca autumnalis, the Face Fly, is the most important vector or transmitter of Thelazia. Eye worm larvae are transmitted when flies feed on horses’ eye secretions.
- Adult worm males are usually 8 – 12 mm in length; females are usually 14 – 18 mm in length.
- Transmission is seasonal – occurs in summer months when flies are out and about.
- Symptoms of Eye worm infection include mild to severe conjunctivitis, lacrimation (tearing) and photophobia (light sensitivity), corneal opacity and/or corneal exudates and pus which can progress to keratitis, corneal ulcers and blindness.
- Diagnosis is via recognition of Eye worms – either adults in conjunctival sac after administration of topical anesthetic or larval forms in lacrimal secretions.
- Only treatment includes removal of any adult worms found. Most conventional anti-parasitic drugs are not effective.
- Fly control is the most important strategy to combat this parasite.
Enjoy this article?
If you enjoyed this article, please take a second to share it via the various social bookmarking sites in the "Share This" link to the right. Don't forget to subscribe to our RSS Feed . Thanks again for visiting us!
Reader Comments
0