First case report of lameness due to Halicephalobus gingivalis in the cannon bone of a horse in France

Halicephalobus gingivalis is a free-living nematode that sporadically infects the central nervous system of equids. Cases of H. gingivalis in France are scarce and mostly associated with neurological signs. This paper documents a first case of lameness due to H. gingivalis in the cannon bone of a horse. Acute onset of lameness of the right leg associated with a painful swelling did not improve under nonsteroid anti-inflammatory treatment. X-rays revealed proliferative and osteolytic lesions. Post-mortem histology revealed the presence of H. gingivalis in the cannon bone. The case confirms the great variety of the clinical signs associated with H. gingivalis infection which should be included in the differential of acute foreleg lameness in horses.