Strongyloidea Flashcards
Strongyloidea (strongyles and hookworms)
Bursate
Adults feed on plugs of mucosa
Most in intestinr
Large buccal capsules
Large strongyles of horses and donkeys
Now uncommon in UK as suscept to macrocyclic lactones
Strongylus spp esp vulgaris (most pathogenic)
Tridomtophorus spp
Direct illifecycle
Migratory
Long prepatent periods
Well dev buccal capsule and prominent bursa
Adults in caecum and colon
Eggs passed in faeces
Dev to L3 takes 2wk in summer
Strongylus vulgaris
L3 penetrate intestinal mucosa and moult to L4 in submucosa after 7d
L4 enter small arteries and migrate to cran mesenteric arrteryafter mnths L4 moult to L5 and return to intestinal wall via arteries
Nodules form around them that rupture and release adult parasites into the gut lumen
Ppp 6-7mnth
Most serious dam caused by migrating larvae cause thrombus inflam thickening of artery wall infarction necrosis
Clin signs ill thrift fatigue anorexia colic
Strongylus dis
Dep on stage
Adult dam intest mucosa by feeding cause incidental haemorrhage and ulcers
High burdens cause anaemia poor condition and colic
Small strongyles
Cyathostomins
Ubiquitous Infect horses and donkeys of all ages Caecum and colon Direct nonmogratory lifecycle L3 exsheath and invade l intest wall L4 emerge into gut lunen and moult to adults Adults are plug feeders on intest mucosa Min ppp 2-3mnth usually longer due to L4 qrrest
Arrested L4 dev of small strongyles
Several species become hypobiotic as L4 when acquired as L3 in autumn
All emerge en masse to complete dev to adults in spring
Larval stage may enter lumen of intest tubular glands and may be reaction upon emergence
Skmilar epidemiology to type 2 oo in cattle
Level of L3 overwintering on pastures dep on prev grazing management and animal treatments
Small strongyle diagnosis
FEC informative but may have low fec but high burden so not used to diagnose
No reliable methods of larvae detection in host
Grazing and worming history and clin signs
Ruminant strongyles
Chabertia ovis
Low nos in colon Direct lifecycle with long ppp Adults ingest mucosa Rare cause clin dis on own Contrib to gastro ent complex White V large buccal capsule
Pig strongyles
Caecum and colon Direct lifecycle Long ppp L4 arrest dev in autumn Adults ingest mucosa Rare cause clin dis in UK Small buccal capsule White
Bird strongyles
Gapeworm
Key parasite of non aquatic game birds and domestic fowl Upper resp tract Form permanent y shape copilae Large red Large buccal capsule
Gapeworm lifecycle
Adult f in bronchi and trachea lay fertilised eggs
Eggs carried up trachea by mucus swallowed and passed in faeces
L3 dev in eggs
Eggs either ingested or hatched L3 ingested or invert transport host eaten
L3 penetrate intest and migrate to lungs
2 moults in lungs
Copilate in trachea and bronchi
Gapes
Excess mucus Haemmorrhagic tracheitis Airway occlusion Pneumonia Clin signs most severe in young birds in outdoor units Control targetted at this grp Keep adults and young separate Goid hygiene Anthelmintic drug prophylaxis pver periods of expected outbreak
Hook worms of dogs foxes and cats
Ancylostoma and uncinaria
High prev in puppies on earth floor kennels
Resp for cutaneous larva migrans in children
Uncinaria stenocephala
Northern hookworm
Dog cat fox Oral ingest L3 Non migratory L3 can penetrate skin but dont continue cycle Prev in sporting dogs
Ancylostoma caninum
Direct
Infect by skin penetration or ingestion of L3
Percutaneous infect:
Pulmonary migration
Moult to L4 in bronchi and trachea, swallowed and pass to s intest where moult to adults
Oral infect:
L1 penetrate buccal mucosa
Pulmonary migration or pas straight to small intest and complete non migratory lifecycle or migrate to skel m and become dormant until react in pregnancy and either pass via milk as L3 or finish lifecycle yrs later migratin to small intestine as hosts get older stressed or debilitated
