Massive mandible osteolysis caused byHalicephalobus gingivalisin a mare

Abstract

Halicephalobus gingivalis infects equines and humans and is reported to be usually fatal in equines. Generally, a diffuse granulomatous inflammation is seen with neurological signs. The authors here present the case of an infected mare that had to be euthanased due to extensive mandible osteolysis, with only bony remnants left. The nematode was clearly identified on histological kidney samples. Interestingly, the affected mare did not present any neurological or renal signs. The only sign noticed was severe mandible deformation, which led to the original referral for suspected mandible fracture. No previous reports describe such a massive mandible osteolysis provoked by this nematode.

Parasitic nephritis and meningoencephalomyelitis in a horse

“…The presence of nematode in the spinal cord and kidney of this horse does not represent the normal distribution of any recognised parasite species, but such lesions have occasionally been described as a result of infection by environmental/commensal parasites in various animal species including horse. The microscopic appearance of the larvae in this horse was morphologically consistent with those representing the free-living opportunistic panagrolaimid nematode, H gingivalis which has been reported as a cause of several cases of neurological disease in horses, in many of which focal renal lesions were also described associated with granulomatous inflammation in various countries including Japan (Akagami and others 2007), USA (Kinde and others 2000), Iceland (Eydal and others 2012), Italy (Cantile and others 1997), France (Roullet and others 2014) and, occasionally over decades, the UK (Khalil and others 1979, Blunden and others 1987, Hermosilla and others 2011). The parasitic/granulomatous nature of the clinically inapparent renal lesion was a surprise.…”

“…Anthelmintic treatment is ineffective and diagnosis of H gingivalis infection is often made by histological examination following autopsy. Fatal meningoencephalomyelitis has recently been reported in human beings (Papadi and others 2013), and there have been recent reports of equine disease in several European countries including Iceland (Eydal and others 2012), France (Roullet and others 2014) and the UK (Hermosilla and others 2011). Increased exposure of animals and human beings to potential infection by the saprophytic nematode may be increased by changing environmental conditions.…”