Onchocerca lupi is an emerging, zoonotic filarioid nematode
associated with ocular disease in companion animals. We report the first
autochthonous case of O. lupi in a dog from Hidalgo County,
southern Texas, USA. An 11-year-old, castrated male, Pitbull dog from
McAllen, Hidalgo County, southern Texas with no travel history, was
diagnosed with a perforating corneal ulceration of the right eye.
Enucleation was performed, and tissues submitted for histopathology.
Sections of two filarioid nematodes were observed. Parasite
identification relied on morphological features seen on histopathology
and molecular confirmation by PCR of the cox1 gene of the mitochondrial
DNA, followed by sequencing and phylogenetic analysis. Our finding
suggests Texas as an additional endemic state for this zoonotic
nematode. Further investigations are required to understand the
epidemiology of this parasite along the United States/Mexico border.