Lids Peeled for Eyeworms

Worms? In the eye? What? Gross! Yes, it happens. We recently diagnosed a pet with eyeworms, and fortunately it’s easily treated.

Eyeworms (Thelazia spp) are most commonly found in large animals, though they can also be found in dogs, cats, and even humans! They are transmitted by flies (including the common house fly) that deposit the eyeworm larvae on the eye while feeding on eye secretions.


Adult eyeworms live in the conjunctival sacs (space between the eyelid and the eye itself) and in tear ducts; small animals (dogs and cats) tend to have smaller conjunctival sacs, making them less ideal hosts. They have been described as “angel hair pasta” (white-ish, 0.5-0.75 inches long) and move in a rapid snake-like motion across the eye, though many of our animal patients present with vague eye signs such as watery eyes, inflamed eye, ulcers, changes to the cornea, and/or blindness.

Luckily, our patient’s owners noticed angel-hair-pasta-like worms moving on his eye before he developed eye signs and brought him in for immediate treatment. We sedated him, numbed the surface of his eyes, and were able to find and remove FOUR adult worms! Although physically removing the adult worms is the best way to treat an animal, we started this kitty on Advantage Multi for eliminating any remaining larvae that weren’t flushed out during treatment (and also for flea and heartworm prevention).

If you suspect eyeworms in your pet, please contact your veterinarian for further treatment.

Nataya Chayasriwong, DVM
Country Oaks Pet Hospital