Nematodes IV: Equine Strongyles Flashcards
What are the large strongyles?
Strongylus vulgaris
Strongylus equinus
Strongylus edentatus
What distinguishes Strongylus vulgaris?
Oval buccal capsule
Ear-shaped teeth at base
What is the life cycle of Strongylus vulgaris?
Females lay eggs, eggs hatch L1 emerges --> L2 --> L3 L3 exsheath in SI ---Enter submucosa of cecum/colon ---Enters walls of submucosal arterioles L4 cecal and colic aa ---Cranial mesenteric artery ---Small arteries of intestinal wall ---Enter tissue (nodules) Adults in nodules ---nodules rupture ---adults enter lumen of cecum/colon
What is the pathology associated with Strongylus vulgaris?
Migrating larvae: Arteritis Thrombi Emboli Intestinal nodules
Adults:
Intestinal nodules
Promote granulation, scarring
What is the larval damage caused by Strongylus vulgaris?
Arteritis
Verminous arteritis
What is the pathology in the arterial system caused by Strongylus vulgaris?
Inflamed/thickened walls
Thromboemboli
Posterior aorta
—aneurysms of cranial mesenteric artery
What is Strongylus vulgaris acute syndrome?
Infarction and necrosis of intestine
Damage to smooth endothelial surfaces
Inflamed/thickened arterial walls
Thromboemboli
What distinguishes Strongylus equinus?
One large tooth and 2 smaller teeth
Dark red or black
What is the life cycle of Strongylus equinus?
Females lay eggs, eggs hatch L1 emerges --> L2 --> L3 ---ensheathed in infective stage L3 exsheaths in SI ---Migrate to cecum, colon ---Encapsulate in subserosal nodules L4 enters peritoneal cavity ---Migrates to liver ---Migrates back to SI through abdominal cavity (pancreas) ---Forms nodules in gut wall ---Nodules rupture into cecum/colon Adults: mature in cecum/colon
What is the pathology with Strongylus equinus mainly due to?
Larvae
What distinguishes Strongylus edentatus?
No teeth
What is the life cycle of Strongylus edentatus?
Females lay eggs, eggs hatch
L1 emerges –> L2 –> L3
—ensheathed in infective stage
L3 exsheaths in SI
—Migrate to cecum, colon
—R ventral colon; through gut wall, enter vessles
—Hepatic portal vein to liver; L3 wander in liver
L4: exit liver through hepatic ligamens
—Tissue under parietal peritoneum to right abd flank
Adults: via mesentery
What is the pathology with Strongyl edentatus mainly due to?
Larvae
What are specific signs for Strongylus vulgaris?
High fever Inappetence Colic ---Gangrenous enteritis ---Intestinal stasis, torsion, or intussusception ---Possible rupture, arteritis ---Especially cranial mesenteric artery
How can you diagnose large strongyle type infections?
Fecal flotation
S. vulgaris: palpation of cranial mesenteric artery