Strongyloides vulgaris - The Damage Done

The internal thoroughfares through which large strongyles travel in their migration through the horse suffer greatly from the traffic. The "footprints" these destructive worms leave can include:

·        Rapid weight loss, loss of appetite, fever, lethargy, dull hair coat, poor performance, a "pot-bellied" appearance, diarrhea and/or constipation--the classic signs of a severely parasitized horse;

·        Localized hemorrhage, swelling, and small bleeding ulcers in the lining of the cecum and colon, thanks to adult large strongyles attaching with their damaging mouth parts and sucking blood (the worms might move to several different sites over their life spans);

·        Anemia and hypoproteinemia (decreased levels of protein in the blood);

·        Irritated and thickened arterial walls in the cranial mesenteric artery and its branches, which supply blood to the small intestine, colon, and cecum (S. vulgaris);

·        Restricted blood flow to the gastrointestinal tract, thanks to partial (or complete) blockages by worms, which can lead to infarctions (areas of dead tissue) (S. vulgaris);

·        Ballooning of the mesenteric artery, called a verminous aneurysm (a sac formed by the stretching of the wall of an artery), can occur in the intestine, heart, kidney, liver, or legs, which can lead to thrombi (blood clots) gathering there like clusters of grapes. If these clots break free, they can block vessels further downstream (S. vulgaris);

·        Severe thrombo-embolic colic due to disruptions of the blood supply to the intestine (S. vulgaris); and

·        In rare cases, complete rupture of the mesenteric artery, which is usually fatal (S. vulgaris).