NEMATODES: Metastongyloidea spp. Flashcards
What general systems of the body are affected by final hosts in metastrongyliodea infections?
Respiratory, vascular, and nervous systems
While most metastrongyloidea spp. have _______ life cycles, some will not including some metastrongylus sp., f. osleri, and f. hirthi.
Indirect
What diagnostic stage is associated with the identification of metastrongyloidea in Baerman tests?
L1
What shapes can the tails of metastrongyloidea be seen in?
Kinked or Straight
What is the common name of the Muellerius spp.?
Lung worm
Who are the intermediate and final hosts of Muellerius sp. infections?
IH = molluscs
FH = Sheep and goats
Where would you expect to find adult Muellerius spp. parasites?
Lung tissues
What is the PPP and life cycle of Muellerius spp.
PPP = 6 - 10 weeks
L1’s are passed in the feces, cutaneously migrate through feet into IH, where they develop into L3’s
The IH is ingested by the FH, and the L3’s are now free to migrate to the lungs and lymph nodes where they develop into adults
Which final host is more affected by severe infections of Muellerius spp.?
Goats; clinical signs of pneumonia in sheep are rare
At necrospy, thickened nodules can be seen along the lungs, what metastronglyoidea spp. would you expect was the parasitic cause?
Muellerius spp.
If an intermediate host for a parasite is an earthworm or mollusc, will control be difficult?
Yes, due to the long life spans of these IH’s
True or False: Strong antihelminthic resistance is associated with Muellerius spp.
False, several antihelminthics have been reported as effective
What is the common name for Parelaphostrongylus tenuis?
Meningeal worm
Who are the IH’s and FH’s of Parelaphostrongylus tenuis, or the meningeal worm?
IH = mollusc
FH = White-tailed deer
What abherrant hosts are associated with Parelaphostrongylus tenuis infections?
Equids, Caprini, and Camelids
Are clinical signs displayed in FH’s or AH’s in Parelaphostrongylus tenius, or meningeal worm, infections?
AH’s, as they display neurological signs due to larval migration tracts and inflammation which can be fatal.
How would one go about diagnosing meningeal worm infections in a camelid?
Observing clinical signs and the presence of white-tailed deer
What is the the life cycle of the meningeal worm?
Adults normally reside in the venous sinuses and subdural sinuses of the brain in white-tailed deer.
Eggs are laid into the blood vessels and move to the lungs for hatching. Occasionally, eggs hatch in the brain, after which the larvae migrate through the blood vessels into the lungs.
First-stage larvae are coughed up, passed in feces, and infect the feet of small terrestrial slugs and snails,
Larvae within the gastropods mature over 3 to 4 weeks to their third stage and are released into the gut of their gastropod host, or possibly its slime trail.
Infective material may then be accidentally ingested by a ruminant, cervid, camelid, or, occasionally, horse.
Larvae penetrate the gut and migrate through the abdomen to the spinal cord, through which they migrate to the brain to complete their life cycle.
What is the PPP of Parelaphostrongylus tenuis in white-tailed deer?
around 3 months
What is the common name for Metastrongylus sp.?
Lungworm of Pigs
Who are the IH’s and FH’s for Metastrongylus sp. infections?
IH = Earthworm
FH = Pig
True or False: In Metastrongylus infections of swine, L1’s are within eggs at the time of elimination via the excretion of feces.
False, they can be found either in the eggs or free in the feces
What typical life cycle do Metastronglyus sp. have?
Indirect predominantly, but some direct life cycles have been reported
What is the PPP associated with Metastrongylus sp.?
1 month
What areas within the lungs would you expect to find Metastronglyus adults?
A) Bronchi
B) Bronchioles
C) Both A and B
D) None of the above
C) Both A and B
What conditions are associated with Metastronglyus infections?
Lung migrations of tissues leading to inflammation and lesions, coughing, and secondary infections
How would a Metastrongylus infection be diagnosed in a fecal examination?
The identification of the L1
Even though there are several antihelminthics, why are young piglets often the most severely affected?
Due to a long exposure, as a result of the IH
What is the common name of Aelurostrongylus abstrustus?
Cat lungworm
Who are the IH’s and FH’s of the cat lungworm, or Alerostrongylus abstrusus?
IH = Snails, slugs
FH = Cats
How might a cat become infected with Aelurostrongylus abstrusus?
Consumption of the IH (snail or slug), or of the PH’s (birds, rodents, frogs)
What tail shape does a L1 Aelurostrongylus abstrusus have?
Kinked
Why are birds, frogs, snakes, lizards, and rodents, considered paratenic, or transport, hosts for Aleulrostrongylus abstusus?
They transport a deceased IH, where the L3 larvae have already developed into and been freed from. The freed L3 does not continue its life cycle until the FH has consumed the transport/ paratenic host.
What is the life cycle of the cat lungworm (Aelurostrongylus abstrusus)?
L3 migration to the lungs leads to further maturation and development into adults, when reproduction can begin.
Eggs are laid into the parenchyma, and develop into L1’s which are then coughed up, swallowed, and defecated out.
L1’s are ingested by an IH and develop into L3’s. The IH at this time can be eaten by a PH and then the FH, or immediately by the FH.
FH ingestion leads to the L3 larvae being liberated in the intestine, penetrating the mucosa, and migrating to the lungs.
True or False: Infection of Aleurostrongylus abstrusus is confirmed by the demonstration of the first-stage larvae in fresh feces, via a fecal flotation or a Baermann, which can also be performed on sputum.
True
4 - What is the PPP of Aleurostrongylus abstrusus?
4 - 6 weeks
What areas of the lung are affected by cat lungworm infections?
Aleurostrongylus abstrusus infections are seen in the lung parenchyma and bronchioles, resulting a chronic mild cough
Who are the FH’s of Filaroides and Angiostrongylus?
Dogs and wild carnivores (foxes, etc.)
Which of the following does not have present with an L1 with a kinked tail?
A) Angiostronglyus vasorum
B) Filareoides hirthi
C) Crenosoma vulpis
D) Filoraoides osleri
C) Crenosoma vulpis
What is the common name of Angiostrongylus vasorum?
French Heartworm
Do F. osleri and F. hirthi have indirect life cycles, or is it A. vasorum and C. vulpis?
Angiostrongylus vasorum and Crenosoma vulpis, their IH’s are snails
What age group of dogs do both Filaroides osleri and Filaroides hirthi affect?
Young dogs
What age group of dogs do both Angiostrongylus vasorum and Crenosoma vulpis affect?
Older dogs, but also foxes!
What predilection site does Filaroidea osleri have in young dogs?
The trachea and bronchi
What predilection site does Filaroides hirthi have in young dogs?
The lungs
What predilection site does Angiostrongylus vasorum (French heartworm) have in older dogs and foxes?
The pulomary arteries
What predilection site does Crenosoma vulpis have in older dogs and foxes?
The bronchi
Upon necropsy, you obsere severe, nodulated bronchii and trachea. Given that the patient presented for respiratory distress, what lungworm would you expect was the cause?
Filaroides osleri
A referred, 8yr MN Labrador Retriever patient is en route for additional cardiac diagnostics, but arrests and dies upon arrival. Given that the patient has been on several medications due to previously diagnosed heart failure, respiratory dysfunction, and a positive fecal test, what parastic agent do you suspect?
Angiostrongylus vasorum
What is the common name for Crenosoma vulpis?
Fox bronchial worm
What is the common name for Filaroides osleriI?
Canine tracheal and bronchial nodular worm
What is the common name for Filaroides hirthi?
Canine lungworm
Which of the following would be most likely responsible for a dry, nonproductive and persistent cough?
A) C. vulpis and F. olseri
B) A. vasorum and F. hirthi
C) F. osleri and A. vasorum
D) F. hirthi and C. vulpis
D) F. hirthi and C. vulpis
Which of the following have the longest prepatent period?
A) C. vulpis
B) F. osleri
C) F. hirthi
D) A. vasorum
B) F. osleri (6 to 7 months)
- C. vulpis* = 19 days
- F. hirthi* = 5 weeks
- A. vasorum* = 1 - 3.5 months
What is the life cycle of the canine tracheal and broncheal nodular worm?
The adults live in nodules in the trachea and bronchi, usually at bifurcations, where they reproduce and females lay their eggs.
Since it requires no intermediate host, the first stage larvae are passed in the feces (L1s are coughed up, swallowed and excreted) or through the saliva (being infective to another dog as L1s can be coughed up and expelled in the sputum).
A ____________, can be used to observe the bronchii when there is a suspected case of Filaroides osleri infection in a dog.
Bronchoscope
A Baermann can be completed on what samples collected from a dog with a suspected Filaroides osleri infeciton?
Fresh feces and sputum
True or False, Crenosoma vulpis has the least antihelminthic resistance, as it can be treated with Fenbendazole, Milbemycin oxime, and Moxidectin.
False, C. vulpis can not be treated with Fembendazole
Which of the following medicaitons would be considered a more broad specturm antihelminthic drug?
A) Milbemycin oxime
B) Moxidectin
C) Praziqunatel
D) Fendebdazole
D) Fendebdazole
Treats for A. vasorum, E. aerophilius (haven’t learned yet), F. osleri, F. hirthi, and P. kellicotti (haven’t learned yet)
