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25 Cards in this Set
- Front
- Back
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Describe the general characteristics of the family Ancylostomatidae
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'hook worms'
buccal end bent dorsad buccal cavity large, cutting plates at outer margin, teeth within stouter nematodes ALL mature in SI ALWAYS direct life cycle eggs typical strongylid percutaneous infection, migration via heart & lungs all SUCK BLOOD |
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Describe the general life cycle of Ancylostomatidae
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percurtaneous [L3] --> blood --> heart & lungs --> SI
other routes (oral) may be used depending on species some can pass to foetus in utero or to suckling young in milk |
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what is cutaneous larval migrans?
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When infective larvae of hookworms penetrate the skin of hosts other than the one in which they will mature. The larvae may migrate in the skin for a time causing irritating lesions, the worms do not mature in abnormal hosts, e.g. A. braziliense
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Name and identify the two species of Ancylostomatidae found in dogs
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Uncinaria stenocephala; more common, less pathogenic, smooth cutting plates, not in milk
Ancylostoma caninum; less common, more pathogenic, toothed cutting plates, can infect via milk |
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Uncinaria stenocephala
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dog (rarely cat)
v.com NZ working dogs 5-12mm long, non-migratory, cutting plates smooth infect oral ore percut, no transmammary or prenatal adult stages cause anaemia and hypoproteinaemia, hypersensitivity may cause severe dermatitis of feet PPP 2 weeks |
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Ancylostoma caninum
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occ in NZ DOGS, more comm in Aussie + tropics
10-16mm, percut, oral, prenatal PPP 2 wks cutting plates toothed, prolific egg layer pathogenicity high due to high blood loss, trigger a degree of eosinophilic enteritis also |
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Name the species of hookworm (Ancylostomatidae) found in NZ cattle
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Bunostomum phlebotomum
stout 12-26 mm long small intestine LC & pathogenesis typical of family Percut more successful than oral PPP 8 weeks |
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Name the species of hookworm (Ancylostomatidae) found in NZ sheep
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Bunostomum trigonocephalum
stout 12-26 mm long small intestine LC & pathogenesis typical of family Percut more successful than oral PPP 8 weeks |
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Name the species of hookworm (Ancylostomatidae) found in NZ pigs
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Globocephalus sp.
has been recorded in rare occasions in NZ- more comm in warmer counteries cutting plates replaced by cuticular ring at the buccal margin |
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Describe the general characteristics of the superfamily Metastrongyloidea
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long slender nematodes
mostly in pulmonary systems LC usually INDIRECT eggs ususally laid with L1 fully developed, may hatch in host and L1 passes in faeces migration via L-P in DH infection via ingestion of infective L3 in IH or occ in secondary PH |
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Metastongylidae
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parasites of pigs, IH earthworms
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Genus Metastrongylus
(M. apri, M. pudendotectus, M. salmi) |
all in pigs, comm esp M. apri
eggs contain L1 when laid and passed in faeces shell mod thick, surface slightly irregular eggs hatch only once ingested by earthworm larvae migrate in earthworm bolld, L3's accm in pseudohearts pig ingests worm --> L-P migration worms mature in DIAPHRAGMATIC lobes of lung PPP 3-4 wks |
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Family Protostongylidae
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parasites of sheep and goats
IH slugs and snails |
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Muellerius capillaris
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comm in sheep and goats NZ
delicate, up to 5cm long terminal bronchioles, alveoli & parenchyma of lungs eggs hatch in lungs; L1 passes in faeces L1 has wavy tail, with 1 or more spines L1 penetrates integument of mollusc (slug), L3 develops here DH infected by accidental ingestion of IH larvae migrate via L-P route |
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Protostrongylus rufescens
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Sheep (recent to NZ, comm overseas)
LC same as Muellerius adult worm in small bronchi not significant cause of disease |
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Varestongylus sp.
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Red Deer NZ
LC as for Muellerius not pathogenic but complicates diagnosis of E.cervi infections |
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Elaphostrongylus cervi
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Red Deer and Wapiti
adults intramuscular connective tissue eggs laid in tissues, L1 develpos, hatches and migrates to lung in blood --> trachea --> alimentary tract L1 passes to faeces --> slugs & snails L3 develops --> accidental ingestion by deer PPP 2-3 months |
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Filaroides osleri
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Dog
nodules beneath tracheal linging at the bifurcation of the trachea occurs in NZ can cause chronic coughing, sometimes pneumonia LC direct, L1 infective (may be in wrong superfamily) |
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Aelurostrongylus abstrusus
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Cat
bronchioles and lung parenchyma L-P migration 7-10mm, very fragile comm in NZ L1 with spine on tail in faeces IH mollusc, usually snail infection usually via PH bird, rodents and reptiles heavy infections cause pneumonia and pleural effusion |
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What protostongylid is commonly found in sheep in NZ?
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Muellerius capillaris
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What is curious about the genus Strongyloides?
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it is able to complete both parasitic and free-living reproductive cycles
Only the females are parasitic |
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describe the diagnostic characteristics of the genus Strongyloides
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only parasitic females
less than 9mm, very slender and delicate oesophagus long, tail bluntly rounded no ovijector apparatus, excretory pore not in notch eggs thin shelled, smaller than typical stongylid, contain L1 when laid, passed in faeces uterus and intestine intertwined |
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Name the species of Strongyloides found in ruminants
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S. papillosus
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Name the species of Strongyloides found in horses
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S. westeri
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Describe the life cycle of a Strongyloides
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percutaneous --> migrate via blood stream to lungs --> SI where they mature
L1 laid in egg --> faeces After being deposited in the faeces larvae may develop either a free-living generation with males and females, or give rise to L3 larvae capable of entering a host animal |
