 |
This article has been peer reviewed but is awaiting expert review. If you would like to help with this, please see more information about expert reviewing. |
| Strongylus vulgaris | |
|---|---|
| Kingdom | Animalia |
| Phylum | Nematoda |
| Class | Chromadorea |
| Order | Rhabditida |
| Family | Strongyloidea |
| Genus | Strongylus |
| Species | S. vulgaris |
Introduction
Strongylus vulgaris is a clinically important parasite of the family Strongyloidea. It causes verminous arteritis and was a very common cause of colic in horses. Its prevalence has been on the decrease since the use of wormers containing ivermectin.
Hosts
Horses and donkeys.
Identification
The adult worms are dark red. The male has a well developed buccal capsule. Both the male and the female worms have rounded teeth, which enable them to hold onto the intestinal mucosa.
The eggs are 100μm x 50μm.
Life cycle
The S. vulgaris eggs are shed in the faeces. Under optimal conditions of high humidity and temperatures over 10 degrees, the eggs will transform into rhabditiform L1 larvae within a few days.
They then transform into L2, and subsequently L3 without leaving the parasite envelope. L3 are ingested by the host when feeding on pasture. L3 enter the small intestine, where they shed their envelope, and then begin migration across the mucosal surface, where they transform into L4.
L4 reach the arterioles of the intestine. Around 2 weeks after the eggs were first ingested they reach the colic and caecal arteries, and then finally the cranial mesenteric artery.
L4 then transforms into the immature adult and returns to the L1 via the blood vessels. Here they form nodules on the wall of the caecum, and occasionally the colon, and are then released into the lumen.
The prepatent period for S. vulgaris is 6-7 months.