Potential re-emergence of the large strongyles

Large strongyle parasites are also referred to as Strongylinae and comprise Triodontophorus spp., Craterostomum acuticaudatum, Oesophagodontus robustus and the three Strongylus species; S. edentatus, S. equinus, and S. vulgaris. Of these, only the equine bloodworm, Strongylus vulgaris, has been associated with a defined clinical syndrome. This parasite is notoriously considered the most pathogenic helminth intestinal parasite of horses, and has been named ‘the horse killer’. The classic disease caused by S. vulgaris is a so-called thromboembolic colic characterised by a verminous endarteritis in the cranial mesenteric artery accompanied by local ischaemia and infarction of segments of the large intestine. Clinically, this is traditionally described as a very painful colic presentation that is associated with a guarded to poor prognosis for survival. However, more recent observations suggest that a majority of cases do not necessarily present with pronounced pain manifestations and some may not be categorised as colic patients at all. Instead, the primary finding is peritonitis caused by bacterial overgrowth of the devitalised intestinal segment. Nonetheless, attempts to medically or surgically treat the condition are often unrewarding and the large majority of cases are euthanised for ethical reasons ...