Onchocerca lupi is a nematode that causes ocular onchocerciasis, an eye disease, in canines and felines.

Females are 275-420 μm in diameter but the total length are unknown while the longest fragments recorded were 160–165 mm.

The morphology and molecular analysis of its partial cox1 and 12S ribosomal DNA sequences were studied to identify.

The magnetic resonance imaging (MRI) scan revealed that a soft tissue mass was running from C2 through C4.

It was suspected that the biopsy process might have killed the worm because the mass reduced in size.