Lecture 5 1/29/24 Flashcards
What are the general characteristics of the Strongylida subfamily Stryongyloidea?
-males with caudal copulatory bursa
-males and females with buccal capsule
-large, heavily sclerotized buccal capsule
-corona radiata/leaf crown of cutting teeth around mouth
What are the characteristics of subfamily Strongyloidea eggs?
-thin-shelled
-morula stage
What are the characteristics of subfamily Strongyloidea general life cycles?
-live in large intestine
-direct lifecycles
-species with both migratory and nonmigratory life cycles
What are the two subfamilies of importance for the Strongyloidea?
-Strongylinae
-Cyathostominae
What are the characteristics of Cyathostomes/small Strongyles species?
-DH is horses
-6-22 mm adult size
-PPP of 6-12 weeks
-eggs 70-100 x 40-50 um*
What are the charactersitics of Cyathostominae/small Strongyles life cycle?
-adults in cecum and colon
-direct life cycle
-non-migratory in body
-develop in nodules in mucosa
-arrest as early L3 in submucosal nodules
-can remain in nodules up to 2 years
-resume development with outside stimulus
What are the characteristics of Small Strongyle Disease/Larval Cyathostominosis?
-large numbers of worms in otherwise healthy horses
-occurs during prepatent period
-predisposition in young horses and those recently dewormed
-often seen in the fall
-death in 50% of cases
What is the infectious stage for Cyathostominae/small Strongyles?
L3
What clinical signs are seen with Small Strongyles Disease?
-diarrhea
-cachexia
-colic
-anorexia
-protein-losing enteropathy
-ventral edema
What leads to clinical signs in Small Strongyles Disease?
mass emergence of encysted larvae
What findings on a CBC can help indicate a small strongyles infection?
-neutrophilia
-anemia
-eosinophilia
What findings on a chemistry panel can help indicate a small strongyles infection?
-hypoalbuminemia
-hyperglobulinemia
-elevated total protein
How can ultrasound be used in diagnosing small strongyles infection?
it can reveal a thickened large intestinal mucosa
What are the large strongyles species of importance?
-Strongylus vulgaris
-Strongylus edentatus
-Strongylus equinus
What are the characteristics of Strongylus vulgaris?
-females 11-16 mm
-males 20-24 mm
-PPP of 6 months
What are the characteristics of Strongylus edentatus?
-females 23-35 mm
-males 33-44 mm
-PPP of 11 months
What are the characteristics of Strongylus equinus?
-females 26-35 mm
-males 35-50 mm
-PPP of 9 months
How does the life cycle of large strongyles differ from that of small strongyles?
-large strongyles have extensive larvae migration within the host before maturation
-in small strongyles, larvae go straight to the intestine and do not migrate
What are the steps of the Strongylus vulgaris life cycle?
-enters wall of distal small intestine, cecum, and ventral colon
-penetrates to submucosa and molts to L4
-L4 penetrates adjacent arterioles and migrates to anterior mesenteric artery
-L4s continue to grow and migrate through vessels
-return to small and large intestine carried by the blood
-occlude arteries, leading to inflammation and arterial wall destruction
-enter submucosa and encapsulate in nodule to molt into adult
-immature adults enter cecum and colon lumen and mature
What clinical signs are seen due to Strongylus vulgaris migration?
-peritonitis
-arteritis
-thrombosis
-embolism
-ischemia
-infarction
-verminous aneurysms
What is the clinical significance of Strongylus vulgaris?
-seen in young horses
-disease occurs during PPP
-pathology associated with larval stages
-most pathogenic of the large strongyles
What are the characteristics of Strongylus edentatus larval migration?
-larvae go to liver first
-from there, migrate through abdominal tissues
-return to colon
What are the characteristics of Strongylus equinus larval migration?
-larvae go to liver first
-migrate through abdomen, primarily pancreas
-return to colon
What are the pathologic characteristics of Strongylus equinus?
-causes pancreatic dysfunction
-associated with peritonitis
-liver pathology occurs
-extremely rare in US
