Final Exam Flashcards
(105 cards)

Strongylus vulgaris
Large strongyle
* thrombus formation, damages arterial wall, infarction
* blood feeders- anaemia, eosinophilia, elevated white cell count
* Epi- larve most abundant on pastures in spring, peak egg laying 10 months after infection
* Life cycle: L1 and L2 in faeces feed on bacteria, L3 exsheaths in SI or LI, migrates into intestinal wall- into wall of arteries and ascends to root of cranial mesenteric arteries, remains for several weeks– returns to gut in blood stream– enters lumen
PPP= 6 months.
* Treatment:
What are the important large strongyles?
Triodontophorus, Strongylus equinus, Strongylus vulgaris, Strongylus edentatus
What are the important small strongyles?
Chabertia, Oe. venulosum, Oe. dentatum, Oe. radiatum, P. rufescens, S. dentatus, Cyathostomum
What are nodule worms?
Oe. radiatum (of cattle- caecum), Oe. columbianum (of sheep- colon), Oe. venulosum (of sheep- caecum), Oe. dentatum (of pigs), Oe. quadrispinulatum (of pigs- significant pathogen)

Strongylus vulgaris

Strongylus vulgaris

Strongylus edentatus
Large strongyle
* L3 exsheaths in caecum, burrows into gut wall, enters portal veins, migrates to liver (8 weeks in the liver), migrates to the sub-peritoneal tissues, returns to gut via mesentery
* PPP= 10 months
* effect on host: found in many organs, migrating larvae cause lesions, adults cause anaemia

Strongylus equinus
Large strongyle
* L3 exsheaths in caecum, migrates into gut wall, peritoneal cavity and liver, spends 6-7 weeks in the liver, migrates via pancreas to gut
PPP= 8 months
* Effect on host: anaemia

Triodontophorus

Triodontophorus
* L3 exsheaths in caecum, L3 migrates into gland, moults to L4, L4 emerges into lumen, final moult in lumen
PPP= 9 weeks
* causes ulceration and blood loss, graze on epithelial lining of gut, occurs in groups

Cyathostomum
small strongyle (encysted)– of horses

Cyathostomum
* encysted small strongyles
* L3 exsheaths in caecum, enters caecal glands, moults to L4, L4 re-emerges into lumen, final moult in lumen
PPP= 5 weeks
* Hypobiosis is important- seasonal pattern, following removal of adults, emergence may be synchronous
* effect on host: adults feed on gut content, not pathogenic, very large numbers can cause diarrhoea, normally 115,000 encysted– can be L4 in wall and come out after treatment synchronously– can be fatal if 200,000 at once.
* Treatment: fenbendazole at 10 mg/kg BW for 5 days and then moxidectin at 0.4 mg/kg BW
* Diagnosis: find eggs in faeces, use mcmaster chamber, >300 epg pathogenic, larval culture to ID genera

Chabertia ovina
*small strongyle of ruminants
* Location: colon
* Hosts: sheep, goats, and cattle
* L3 exsheaths in SI, enters mucosal galnds, moults to L4, L4 returns to lumen, migrates to large intestine, final moult in LI
PPP= 8 weeks
* effect on host: feed on mucosa, causes haemorrhage, excess mucous production, diarrhoea, more prevalent in temperate areas, strong immunity develops, usually only a few present… > 200 pathogenic, females lay 3000 eggs/day

Oesophagostomum radiatum
* nodule worms of cattle
* L3 migrates into glands in SI and/or LI, L4 emerges and migrates to LI
PPP= 5-6 weeks
* effect on host: susceptible young host- no reaction and therefore nodule formation (second time larger nodules due to hypersensitivity)… but resistance animals intense reaction of the immune system– eosinophilia.. and less nodules formed… some will migrate into the lumen and develop into adults but not many.
** nodules will interfere with gut motility, anorexia, reduced weight gains, and diarrhoea in adults
* strong immunity by 12 months of age

Stephanurus dentatus
* eggs passed in urine, L3 ingested or can penetrate skin, migrate to liver via portal system (3 days) or aorta (8-40 days), migrate in liver for 2-3 months, migrate to perirenal area…. may migrate anywhere in the body
PPP= 9 months
* effect on host- fibrosis in liver, abscesses in carcass, organs condemned at slaughter, weight loss
* Diagnosis- eggs in urine, elevated liver enzymes

Syngamus trachea
* Eggs coughed up, swallowed, L1-L3 within egg, molluscs, oligochaetes are the paratenic hosts, L3 ingested, migrates to trachea via liver than lungs (in circulation)
PPP= 2 weeks
* effects on host: excess mucus production, block airways, respiratory distress- birds gape, blood feeders
* Diagnosis- eggs in feaces (ellipsoidal thin shelled eggs with a thick operculum at both sides)

Ancylostoma caninum
* encysted strongyles
* treatment: fenbendazole and moxidectin (day 40 pregnancy treatment regime everyday until whelping will kill greater than 90% of larvae)
* skin penetration and transmammary infection important
* adult can be dormant in muscles–> SI (via circulation)
* Effect on host: females 0.1 ml/day, black tarry faeces, microcytic, hypochromic anaemia, heavy infestations (pups) cause death, strong immunity following exposure
* epi: common in warm climates, less common in southern Australia, sandy or loam areas ideal for larva
* Diagnosis: eggs in faeces, egg counts high > 5000 epg, eggs small < 65 micrometers
* older dogs- chronic
* zoonosis (eosinophilic enteritis in man)

Ancylostoma braziliense
* common in tropical and sub-tropical regions
* less pathogenic- can cause hypoproteinaemia and diarrhoea
* primary cause of cutaneous larva migrans or creeping eruption in man
* tortuous erythmatous inflammatory tracts within dermis associated with severe pruritis

Bunostomum phlebotomum- cattle- SI
* found mainly in warm areas, skin penetration, transcolostral infection
* cause anaemia, hypoproteinaemia and 1000 fatal burden!!!
PPP= 7 weeks

Bunostomum trigonocephalum- sheep- SI
* found mainly in warm areas, skin penetration, transcolostral infection
* cause anaemia, hypoproteinaemia and 1000 fatal burden!!!
PPP= 7 weeks

Globocephalus- hookworms of pigs
* found mainly in warm areas, skin penetration, transcolostral infection
* cause anaemia, hypoproteinaemia and 1000 fatal burden!!! Weight loss too
PPP= 7 weeks
General characteristics

Dictyocaulus spp.
* long slender worms
* up to 10 cm long
* location- trachea and bronchi
Main hookworm of dogs

Uncinaria stenocephala
* common in cooler areas
* L3 are ingested
* no extra- intenstinal migration
* less pathogenic
* eggs > 65 micrometers

Strongylus equinus

























































