First report of canine ocular thelaziosis by Thelazia callipaeda in Portugal.
BACKGROUND
Thelazia callipaeda eyeworms are transmitted by the non-biting insect vector Phortica variegata in Europe and infest the conjunctiva(s) of several mammalians, including dogs and humans. Infested hosts might remain asymptomatic or display clinical manifestations characterized by variable degrees of severity.


METHODS
From July to November 2011, nine dogs were detected with eyeworms at two veterinary clinics in Chaves and Bragança (North of Portugal). Nematodes collected from dogs were morphologically and molecularly characterized at species level.


RESULTS
Nematodes were identified as T. callipaeda. The number of worms collected from each dog ranged from three to 76 (average = 17.9 ± 26.8) and was not associated with the severity of clinical signs. Ocular discharge and conjunctivitis were observed in all dogs and ocular pruritus occurred in six of them. Polymerase chain reaction and sequencing of a portion of target cytochrome c oxidase subunit 1 gene further identified all nematodes as haplotype 1.


CONCLUSIONS
This is the first report of T. callipaeda and associated ocular disease in dogs from Portugal, suggesting that thelaziosis should be included in the differential diagnosis of canine ocular affections. The risk of the infestation spreading from Spain and France to Portugal, through domestic dogs or wild mammals, is realistic.
Os Bichos Veterinary Clinic, Chaves, Portugal.
Lisete
L
Vieira
Filipa T
FT
Rodrigues
Alvaro
A
Costa
Duarte
D
Diz-Lopes
João
J
Machado
Teresa
T
Coutinho
Joana
J
Tuna
Maria Stefania
MS
Latrofa
Luís
L
Cardoso
Domenico
D
Otranto
D000818:Animals; D004283:Dog Diseases / Q000453:epidemiology / Q000469:parasitology*; D004285:Dogs; D005260:Female; D008297:Male; D011174:Portugal / Q000453:epidemiology; D017205:Spirurida Infections / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D013802:Thelazioidea / Q000145:classification / Q000302:isolation & purification*