Wormopedia - Eyeworms

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Eyeworm slide

Eyeworm (Thelazia callipaeda)

Eyeworm (Thelazia callipaeda) occurs in dogs, cats and humans in southern Europe and is transmitted by deer flies picking up the infection from the tears of animals and humans.
- AT RISK -
Eyeworm slide

Eyeworm (Thelazia callipaeda)

Eyeworm was first discovered in the eyes of a dog in China in 1910*
*Railliet, A.; Henry, A. (1910). "Les Thelazieo, Nematodes parasites de l'oeil". Comptes rendus des séances de la Société de biologie et de ses filiales 68: 213–216, 783–785
Eyeworm slide

Eyeworm (Thelazia callipaeda)

Symptoms
As the name suggests symptoms are generally confined to the eye area, but they can range from teariness, conjunctivitis and discharge to inflammation and ulcers on the cornea.
Eyeworm slide

Eyeworm (Thelazia callipaeda)

Lifecycle...
In both dogs and people, larvae (L3) mature into adult worms on the eye/under the eyelids; adults release first stage larvae (L1) into the tears
Fly feeds on dog's tears and transmits infective L3
L1 matures within fly to L2 and then L3 - this takes about 3 weeks
Fly picks up L1 while feeding on dog or human tears
Eyeworm slide

Eyeworm (Thelazia callipaeda)

Infection stages
It can take about 3 weeks from infection to the development of symptoms in dogs.
Eyeworm slide

Eyeworm (Thelazia callipaeda)

Risk to humans
Humans can occasionally become infected by the flies that spread the infection to pets.
Eyeworm slide

Eyeworm (Thelazia callipaeda)

Spread in Europe
Eyeworm is increasingly being found throughout Europe, notably in Italy, Switzerland, France, Germany, Spain and Portugal.
Eyeworm slide

Eyeworm (Thelazia callipaeda)

How to get rid of them
A 'vet strength' wormer can be effective at treating eyeworm in cats and dogs.

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