First report of canine thelaziosis caused by Thelazia callipaeda in Bhutan
5 affiliations
- 1District Veterinary Hospital, Punakha, Bhutan
- 2Department of Food Science and Technology, College of Natural Resources, Royal University of Punakha, Bhutan
- 3Department of Veterinary Medicine, University of Bari “Aldo Moro”, Valenzano, Italy
- 4Department of Veterinary Clinical Sciences, City University of Hong Kong, SAR, China
- 5Parasitology Unit, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
Abstract
Thelazia callipaeda is a vector-borne zoonotic nematode causing ocular infection in animals and humans, with an expanding geographical range across Asia, Europe, and North America. Although the parasite is endemic in neighbouring countries China and India, no cases of canine thelaziosis have previously been reported in Bhutan. Here we describe the first case of canine ocular thelaziosis, in a 7-year-old mixed-breed dog from Punakha District presenting with bilateral lacrimation and epiphora, conjunctival hyperemia, and blepharospasm. Thirty-two whitish, thread-like nematodes were recovered from the conjunctival sacs of both eyes and identified morphologically as T. callipaeda based on cuticular striae, buccal capsule morphology, and characteristic male and female reproductive structures. Molecular confirmation was achieved by sequencing a fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, which showed 99.6% identity to an isolate of T. callipaeda from India. Phylogenetic analysis placed the Bhutan isolate within the Asian clade, clustering most closely with the Indian isolate. This report describes the diagnosis and successful management of the first confirmed case of canine ocular thelaziosis in Bhutan, underscoring the need for veterinary and public health surveillance of thelaziosis in this region.
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BibTeX
@article{tshering2026first,
title = {{First report of canine thelaziosis caused by Thelazia callipaeda in Bhutan}},
author = {Rinchen Tshering and Karma Wangchuk and Domenico Otranto},
journal = {Current Research in Parasitology \& Vector-borne Diseases},
year = {2026},
month = oct,
doi = {10.1016/j.crpvbd.2026.100450},
url = {https://doi.org/10.1016/j.crpvbd.2026.100450},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - First report of canine thelaziosis caused by Thelazia callipaeda in Bhutan
AU - Rinchen Tshering
AU - Karma Wangchuk
AU - Domenico Otranto
PY - 2026
DA - 2026/10/20
JO - Current Research in Parasitology & Vector-borne Diseases
DO - 10.1016/j.crpvbd.2026.100450
UR - https://doi.org/10.1016/j.crpvbd.2026.100450
AB - Thelazia callipaeda is a vector-borne zoonotic nematode causing ocular infection in animals and humans, with an expanding geographical range across Asia, Europe, and North America. Although the parasite is endemic in neighbouring countries China and India, no cases of canine thelaziosis have previously been reported in Bhutan. Here we describe the first case of canine ocular thelaziosis, in a 7-year-old mixed-breed dog from Punakha District presenting with bilateral lacrimation and epiphora, conjunctival hyperemia, and blepharospasm. Thirty-two whitish, thread-like nematodes were recovered from the conjunctival sacs of both eyes and identified morphologically as T. callipaeda based on cuticular striae, buccal capsule morphology, and characteristic male and female reproductive structures. Molecular confirmation was achieved by sequencing a fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, which showed 99.6% identity to an isolate of T. callipaeda from India. Phylogenetic analysis placed the Bhutan isolate within the Asian clade, clustering most closely with the Indian isolate. This report describes the diagnosis and successful management of the first confirmed case of canine ocular thelaziosis in Bhutan, underscoring the need for veterinary and public health surveillance of thelaziosis in this region.
SN - 2667-114X
ER -