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Thelazia callipaeda: infection in dogs: a new parasite for Spain

Guadalupe Miró1*, Ana Montoya1, Leticia Hernández1, Diana Dado1, María Victoria Vázquez2, Marta Benito3, Manuel Villagrasa4, Emanuelle Brianti5 and Domenico Otranto6

Author Affiliations

1 Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, de Madrid, Spain

2 Clínica Veterinaria "El Mundo Animal", Villanueva de la Vera, Cáceres, Spain

3 Clínica Veterinaria Candeleda, Candeleda, Ávila, Spain

4 Centro Veterinario Oftalmológico Goya, Madrid, Spain

5 Dipartimento di Sanità Pubblica Veterinaria, Facoltà di Medicina Veterinaria, Università degli Studi di Messina, Messina, Italy

6 Dipartimento di Sanità Pubblica e Zootecnia, Università degli Studi di Bari, Valenzano (Bari), Italy

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Parasites & Vectors 2011, 4:148  doi:10.1186/1756-3305-4-148

Published: 27 July 2011



Thelazia callipaeda (Spirurida, Thelaziidae), eyeworms, are known as the causative agents of thelaziosis, initially described in Asia and, later on, over the last decade, also in some European countries (e.g., Italy, France, Germany and Switzerland). In June 2010, the first case of canine thelaziosis was observed in central western Spain (La Vera region, Cáceres) and subsequent epidemiological investigation is reported in the present study.


This study describes the first autochthonous cases of infection by T. callipaeda in dogs from central western Spain where the first case of eyeworm infection was reported.

A total of 456 dogs was examined in this geographical area. Thelazia callipaeda eyeworms were observed in 182 (39.9%) animals, of which 28 showed apparent clinical signs (i.e., conjunctivitis, oedema, epiphora and petechiae). A total of 762 adult nematodes (214 males, 548 females; mean infection rate of 4.18; SD 4.74) were collected with cotton swabs or by flushing of the conjunctival sac of infected animals using physiological saline solution. Nematodes were identified as T. callipaeda according to the morphological keys and molecular analysis of sequences of a portion of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. The sequences were identical to those representing T. callipaeda haplotype 1, previously reported in Europe.


The high infection rate of canine thelaziosis herein reported suggests that practitioners should include this eye infection amongst differential diagnoses of ocular diseases in dogs from this area of Spain or those moving across this area of Spain. Based on the high infection prevalence recorded, the potential public health risk to humans from this region is also discussed.