6.10 Nematodes - Strongylids - Hookworms and Lungworms Flashcards
the strongylids group contains what worms (4)
Strongyles, trichostrongyles, hookworms, lungworms
most strongyles have how many hosts and what is the exception
1 (exception = lungworms)
what is the general size of strongylids compared to other nematodes
smaller nematodes
which strongylids are slender and which are more stout-bodied
slender: trichostrongyles, lungworms
stout: strongyles, hookworms
what is the morphology of all strongyle eggs
thin-shelled, morulated eggs (GIN eggs, strongyle egg or hookworm egg… all mean the same thing)
what is the main form of transmission of Strongylids
oral transmission of L3s; some penetration of skin
what is the common hookworm of the canine small intestine
Ancylostoma caninum
where is Ancylostoma caninum prevalent and where is it less common
common in south and temperate regions; less common in Ontario
what are the morphological features of Ancylostoma caninum
- stout
- bent at buccal cavity
- buccal cavity has 3 large pairs of teeth
most Strongylid eggs are thin-shelled and morulated… what does this say about their persistence in the environment
egg hatches in the environment
what is the life cycle of Ancylostoma caninum - what type of life cycle is this
DIRECT life cycle
morulated eggs passed in feces -> L1 develop to L3 -> L3 penetrates skin of dogs (or people) -> tracheal migration in young dogs, somatic migration in older dogs, somatic migration can give rise to transmammary infection in lactating dogs
note: ingestion of L3s gives rise to mucosal migration and patent infection
T/F paratenic hosts play a minor role in the Ancylostoma life cycle
T
what is the PPP for Ancylostoma caninum
1) transmammary
2) other routes
1) transmammary: 2 1/2 weeks
2) other routes: 3-4 weeks
what is the pathogenesis of Ancylostoma caninum (6)
- anemia
- hypoproteinemia -> edema
- melena
- emaciation
- enteritis
- death
the same anthelmintics used against ascarids are also affective against hookworms with the exception of:
piperazine
what is the common hookworm of cats
Ancylostoma tubaeforme
what is the morphological appearance of Ancylostoma tubaeforme
similar to A. caninum
- stout-bodies
- bent at buccal cavity
- buccal cavity has 3 rows of teeth
- thin-shelled, morulated egg
what is the life cycle of Ancylostoma tubaeforme - what type of life cycle is this
DIRECT life cycle
morulated eggs passed -> L1 develop to L3 -> L3 penetrate skin of cats -> tracheal migration in young, somatic migration in older, somatic migration can give rise to transmammary infection in lactating cats
what is the pathogenicity of Ancylostoma tubaeforme
little known but presumed similar to Ancylostoma caninum (enteritis, hypoproteinemia, hemmorhage, edema, melena, emaciation, death)
what are good treatments for feline hookworm (Ancylostoma tubaeforme)
pyrantel pamoate-based treatments
what is the name of the northern hookworm
Uncinaria stenocephala
does Ancylostoma or Uncinaria have a larger GIN egg
Uncinaria
what is the life cycle of Uncinaria - what type of life cycle is this
DIRECT life cycle
morulated eggs passed -> L1 develop to L3 -> L3s INGESTED -> mucosal migration
what is the PPP of Uncinaria
2 1/2 weeks
what is the pathogenesis of Uncinaria stenocephala
much less pathogenic vs Ancylostoma
- anemia
- hypoproteinemia
- enteritis
how should you treat a hookworm/roundworm problem in puppies if one is suspected/known
treatment starting at 2 weeks of age and continuing every 2 weeks until 12 weeks of age
what are the hookworms
Ancylostoma and Uncinaria
what do most lungworms shed - larvae or eggs?
larvae
what is the DH and IH of Muellerius
IH: snails, slugs
DH: small ruminants (sheep, goats)
what is the predilection site of Muellerius
alveoli and terminal bronchioles
what is the diagnostic stage for Muellerius
L1 in the feces
what is the life cycle of Muellerius - what type of life cycle is this
INDIRECT
L1 larvae shed -> L1 develop to L3 -> L3 ingested by IH -> DH ingests IH -> L3 travel to alveoli and terminal bronchioles
what is the pathogenesis of Muellerius capillaris
- alveolar rupture
- focal interstitial pneumonia
- granuloma formation
what areas of the lung are mainly affected by Muellerius capillaris
ventral
what are treatment options for Muellerius
ivermectin, levamisole (no registered compounds)
what is the life cycle of Filaroides and Oslerus? What type of life cycle is this
DIRECT
L1 shed into environment -> L1 infective -> tracheal migration -> adults in final site (depends on the species: Oslerus = trachea and bronchi; Filaroides = terminal bronchioles and alveoli)
what is the PPP of
- filaroides
- oslerus
Filaroides: 5 weeks
Oslerus: 10 weeks
what is the pathogenesis of Filaroides
usually asymptomatic
what is the pathogenesis of Oslerus
tracheitis, bronchitis, wheezing cough, dyspnea (from the nodules and released eggs/larvae)
how can we diagnose Filaroides and Oslerus infections
Baermann; visualize Oslerus nodules with endoscopy
how can we treat Filaroides and Oslerus
remove Oslerus nodules surgically; off-label use of anthelmentics
what type of sample is needed to run a Baermann
FRESH, unfixed fecal matter
what is the true lungworm of:
- dogs
- cats
- small ruminants
dogs: Oslerus, Filaroides
small ruminants: Muellerius
cats: Aelurostrongylus
what is the predilection site of Aelurostrongylus
terminal bronchioles and alveoli
T/F Aelurostrongylus requires an intermediate host
T (snails and slugs)
what is the characteristic appearance of Aelurostrongylus
adults have a small bent tail with a dorsal spine
what is the life cycle of Aelurostrongylus
larvae passed in feces -> L1 infect snail/slug -> moves up food chain -> ingested by DH -> moves from stomach to predilection site in lungs
what is the PPP of Aelurostrongylus
5-6 weeks
what is the pathogenesis of Aelurostrongylus
focal granulomatous pneumonia; cough and dyspnea
how do we diagnose Aeourostrongylus
Baermann
what is the IH and DH of Crenosoma
IH: mollusks
DH: dogs, foxes, wolves, racoons
what is the predilection site of Crenosoma
terminal bronchioles and alveoli
what is the characteristic appearance of Crenosoma
anterior cuticle has folds
how do we detect Crenosoma
Baermann
what is the life cycle of Crenosoma
larvae passed in feces (L1) -> L1 infect mollusks -> DH ingests IH containing L3 larvae -> migration to predilection site -> adults in bronchi and bronchioles
what is the pathogenesis of Crenosoma
focal lesions in lungs; rhinotracheitis, bronchitis, may see nasal discharge
