Unit 3 - Strongyloides & Ascarids Flashcards
Strongyloides ransomi
swine
Strongyloides westeri
equids
Strongyloides papillosus
ruminants
Strongyloides stercoralis
canids
Strongyloides tumefaciens
felids
What is the strongyloides infective stage?
L3
The free living stages of Order Rhabditida (strongyloids) are:
L1 & L2
Free living life cycles are associated with:
heterogenic
parasitic life cycles are associated with:
homogenic
Which stage of the life cycle is passed in the feces for the free living strongyloides?
L1
Which stage of the life cycle is passed in the feces for the parasitic strongyloides?
larvae
Strongyloides larvae in contaminated soil:
penetrate the skin
For the strongyloides parasitic life cycle, what is the only gender of parasite that is actually parasitic?
females
What are the two ways the preoral transmission can move through the body?
- penetrate oral mucosa and migrate (as percutaneous does)
2. ingest infective L3; go directly to SI
What are the routes of infection utilized by S. ransomi (swine)?
- percutaneous *
- preoral
- transmammary **
- transplacental
What are the routes of infection utilized by S. westeri (equids)?
- percutaneous
- preoral
- transmammary **
What are the routes of infection for S. papillosus (ruminants)?
- percutaneous
- transmammary
What are the routes of infection for S. stercoralis (canids)?
- percutaneous
What are the routes of infection for S. tumefaciens (felids)?
- percutaneous
- preoral
What is the primary route of infection for S. papillosus in sheep/goats?
percutaneous
What is the primary route of infection for S. papillosus in cattle?
transmammary
What type of infection of S. ransomi is key to epidemiology in swine?
transmammary
S. ransomi pathogenicity is usually in:
nursing piglets (b/c of transmammary infection)
What are the clinical signs of S. ransomi in piglets?
- acute enteritis
- bloody diarrhea, anemia, severe weight loss, stunted growth
What is the best way to manage S. ransomi infections in pigs?
- high level of hygiene esp. in pens
Which horses most commonly see infections of S. westeri?
suckling and weanling foals
What is the most important transmission method for S. westeri in horses?
transmammary transmission
When do foals shed S. westeri eggs?
10-14 days after birth
S. westeri clinical signs (3):
- usually inapparent
- catarrhal enteritis
- diarrhea
What is the zoonotic potential of S. westeri?
creeping eruption - allergic response to free-living L3 in humans
Which strongyloides spp. have zoonotic potential?
- ransomi
- papillosus
- westeri
What are some of the clinical symptoms of S. papillosus?
- usually inappetent
- usually warmer climates
- diarrhea
- anorexia
What is the peak time of infection for calves with S. papillosus?
1-3 months
What is the peak time of infection for lambs/kids with S. papillosus?
2-6 weeks
Transmission route for S. papillosus?
Percutaneous - bacteria readily enter inter-digital skin (foot rot)
S. papillosus, is more generally seen in (geography):
warmer climates
What are the more prominent clinical symptoms of S. papillosus in kids/lambs/calves?
ataxia due to brain lesions (also diarrhea, dehydration, anorexia, and emaciation)
What is the appropriate diagnostic method for S. ransomi, westeri, and papillosus?
fecal flotation
Describe the visual characteristics of S. ransomi, westeri, and papillosus eggs:
- oval
- thin-shelled
- larvated
Give me the two most important characteristics of the adults of S. ransomi, westeri, and papillosus:
- embedded in SI mucosa
2. generally nee skin scraping of the mucosa
What is the most important prevention method for S. ransomi, westeri, and papillosus?
maintain clean, dry environment
What is the most rare form of infection associated with S. stercoralis?
autoinfection
What are the infective stages of S. stercoralis?
L3a (auto-infection) and L3i (infective)
What is the path/development of L3a of S. stercoralis?
- develop within the intestine of dog
- invade dog through wall of large intestine
What is path/development of L3i of S. sterocralis?
- develop in environment
- invade dog through skin
S. stercoralis can be asymptomatic to serious. What are some of its clinical symptoms?
- dermatitis
- catarrhal enteritis
- necrosis of intestinal mucosa
- mucoid/bloody diarrhea
- dehydration
- bronchopneumonia (cranioventral)
- death
Where can the L3a of S. stercoralis be found for diagnosis?
lung of host
Although only a few S. stercoralis L3a can be found in the lung at any one time, damage to the lung can be:
severe
What stage of S. stercoralis will be seen in feces of infected host?
L1
What is the technique of choice for diagnosing S. stercoralis?
Baermann - use fresh L1
Diagnosing of S. stercoralis by using the adults can be done using what 4 tests?
- mucosal scraping
- parasitic female
- IFAT
- ELISA
Where is S. stercoralis most often a problem?
kennels
What is a major problem associated with S. stercoralis?
its zoonotic potential
Which strongyloides species is a rare infection seen in cats?
tumefaciens
What clinical signs are seen with S. tumefaciens?
grossly visible tumor-like nodules
Where can S. tumefaciens be seen in the host?
large intestine (colonoscopy)
Which ascarids are found in poultry?
- Ascaridia galli
- Heterakis gallinarum
Which ascarids are found in swine?
Ascaris suum
Which ascarids are found in equids?
Parascaris equorum
Which ascarids are found in raccoons and dogs?
Baylisascaris procyonis
Which ascarid is found in both dogs and cats?
Toxascaris leonina
Which ascarid is found only in dogs?
Toxocara canis
Which ascarid is found only in cats?
Toxocara cati
What is the PH of both Ascaridia galli and H. gallinarum?
earthworm
Clinical symptoms associated with Ascaridia galli?
- anorexia
- unthriftiness
- diarrhea
- dull plumage
- decreased egg production
What causes the symptoms associated with H. gallinarum?
the protoza that transfers it - Histomonas meleagridis
Which species is most important when dealing with H. gallinarum and H. meleagridis?
turkeys
What’s the difference in the PH of Ascaridia galli and H. gallinarum?
- Ascaridia: PH ingests L3
- Heterakis: PH ingests L2
Where are the L3, L4, and adults located for Ascaridia galli?
All are in SI
Where are the L3, L4 and adults located for H. gallinarum?
All are in Ceca
What is the most significant lesion assocaited with H. gallinarum?
typhlitis (inflammation of cecum)
How do you diagnose Ascaridia galli and H. gallinarum?
fecal flotation for eggs
What are the paratenic hosts for Ascaris suum (swine)?
- dung beetle
- earth worm
Where are the infective L3 of Ascaris suum released?
SI mucosa (then undergo hepato-pulmonary migration)
What stage of Ascaris suum is ingested by the PH?
L3
Ascaris suum pathogenesis associated with the liver:
- cellular destruction
- interstitial hepatitis
- “milk spots” (localized fibrotic areas)
Ascaris suum pathogenesis associated with the lungs:
- hemorrhage, bronchitis, edema
- pneumonia in young pigs
Ascaris suum pathogenesis associated with SI:
- catarrhal enteritis
- adult worms interfere with nutrition
- obstruction or perforation
Ascaris suum clinical signs (5):
- coughing
- “thumps” (rapid, shallow breathing)
- unthriftiness
- colic
- weight loss
Diagnosis of Ascaris suum is dependent upon:
fecal float - eggs
adult stages - necropsy
clinical signs
Different clinical signs associated with Parascaris equorum are due to:
different stages
P. equorum larvae cause what clinical signs (2):
coughing
bilateral mucopurulent nasal discharge
How can you diagnose Parascaris equorum?
eggs - fecal float
adults - necropsy (in SI)
What is the only difference in life cycles for Ascaris suum (pigs) and Parascaris equorum?
A. suum has a potential paratenic host
What is one of the most significant parts of the T. leonina life cycle?
no somatic migration
Why is there no mammary or transplacental transmission associated with T. leonina?
no somatic migration
Which is more common: Toxocara spp. or Toxascaris?
Toxocara spp.
Very rarely are Toxascaris leonina infections reported in:
humans
How do you diagnose Toxascaris leonina?
eggs - fecal float
adults - necropsy, vomit, feces
What is the most important route of infection for Toxocara cati?
transmammary - infection ONLY when queen is lactating
Clinical signs of Toxocara cati:
- often asymptomatic
- pot-bellied
- failure to thrive
The L3 for Toxocara canis ALD and reactivate for which two routes of infections?
- mammary
2. transplacental
What happens when Toxocara canis infects puppies?
transplacental –> fetal liver –> neonatal lungs; L3 to stomach
What are the clinical symptoms associated with Toxocara canis in puppies?
- verminous pneumonia
- enteritis
- Ulcers in SI
- occlusion of SI (uncommon)
- death possible
Toxocara canis diagnosis:
eggs - fecal float
Describe what Toxascaris leonina looks like on fecal float:
- smooth surface
- empty space within the egg
What is the PH for Baylisacaris procyonis?
small mammals, birds
What is the pathology for Baylisacaris spp. in the DH?
usually none
What is the pathology for Baylisacaris spp. in other species?
- mechanical damage to tissues
- brain and spinal cord lesions
- lung damage (from migration)
- inflammation, hemorrhage, necrosis