Equine Parasites: Nematodes II Flashcards
In general, Strongyloides nematodes have a/an _________ lifecycle with ______ infective stage.
DIRECT lifecycle with L3 infective
What is the common name for subfamily Strongylinae?
Large strongyles
Name the equine parasites included in subfamily Strongylinae (large strongyles).
S. vulgaris
S. edentatus
S. equinus
Name the equine parasites included in subfamily Cyathostominae (small strongyles)
Cyathostomins
What is interesting about the history of Large and Small Strongyles?
Large strongyles used to be the problem parasites, but after effective treatment using MCLs, small strongyles are now the main problem causing parasite.
The following characteristics describe what type of strongyle?:
Larvae migrate in organs
Colic
Adults are bloodsuckers/plug feeders which causes anemia
Large strongyles (S. vulgaris, edentatus, and equinus)
The following characteristics describe what type of strongyle?:
More than 50 species
Larvae damage the large intestine mucosa causing colic and diarrhea
Resistance has been noted
Small Strongyles (Cyathostominae)
How big are adult large strongyles?
1.5 to 5 cm
How big are adult small strongyles?
Less than 1.5 cm
Where would you find adult large or small strongyles?
The lumen of the large intestine
Can you distinguish between the eggs of a large strongyle and small strongyle? How big are the eggs?
No, you cannot differentiate between them.
60- 120 x 35- 60 Mm
What is the PPP of large strongyles?
6 to 11 months
What is the PPP of small strongyles?
1.5 to 4 months
What is the difference between the migration of large and small strongyles?
LARGE strongyles migrate through ORGANS
SMALL strongyles migrate locally and ENCYST in intestinal walls
Which strongyle is resistant to antihelminthics?
Small strongyles
What color are adult Strongylus vulgaris worms?
“Red worms”
Large strongyles have _________ mouth capsules.
GLOBULAR
Which large strongyle has a PPP of 6 months?
S. vulgaris
Which large strongyle has a PPP of 9 months?
S. equinus
Which large strongyle has a PPP of 11 months?
S. edentatus
Which large strongyle migrates to the cranial mesenteric artery?
S. vulgaris
Which large strongyle migrates to the liver via direct migration?
S. equinus
Which large strongyle migrates to the portal vein of the liver and sub-peritoneal connective tissue?
S. edentatus
How long is the adult S. vulgaris?
1-2 cm
What does Strongylus vulgaris larva cause?
Arteritis, thrombus, infarction, death
What clinical signs does larva of Strongylus vulgaris cause?
Thrombo-embolus, and colic
What clinical signs do adults of Strongylus vulgaris cause?
Anemia because they are bloodsuckers
How long are Strongylus edentatus adults?
3-4 cm
Where would you find Strongylus edentatus larval stages?
In liver and abdominal tissue (flanks)
What are some symptoms associated with a Strongylus edentatus infection?
Larva: Fever, anorexia, and intermittent colic
Adults: Anemia
How long are Strongylus equinus adults?
3-4 cm
The larvae of which large strongyle forms hemorrhagic tracts?
Strongylus equinus
How do you diagnose a large strongyle infection?
Identifying L3 in a fecal exam
The mouth capsule of small strongyles/Cyathostomins is _______ in shape.
Rectangular or square
What is the PPP of small strongyles/Cyathostomins?
6 weeks to 2-4 months
There are over 51 species of ___________.
small strongyles/Cyathostomins
Small strongyles/Cyathostomins can arrest development for how long?
2.5 years
Where would you find small strongyles/Cyathostomins larva?
Large intestine mucosa
Catarrhal colitis and protein losing enteropathy are characteristic of what parasite?
small strongyles/Cyathostomins
Clinical signs of a small strongyles/Cyathostomins infection are associated with what?
The emergence of L4
The following characteristics describe what parasite?: Chronic diarrhea Colic Seasonality Severe weight loss Edema
small strongyles/Cyathostomins
How do you diagnose small strongyles/Cyathostomins?
Fecal exam using McMaster and distinguish if L3 is a large or small strongyle
Why would you find small strongyles/Cyathostomin eggs in the feces of foals less than 6 weeks of age?
Coprophagia
In the North, small strongyles/Cyathostomins larva _______ in the winter, and emerge in the ______.
ARREST in the winter and emerge in the SPRING
In the South, small strongyles/Cyathostomins larva ________ in the summer and transmission occurs in the _________.
larva ENCYST in the summer and transmission occurs in the WINTER
What is the origin of infection of small strongyles/Cyathostomins?
The mare is the origin of infection
What is used to treat a small strongyles/Cyathostomins infection?
BZs and MCLs, resistant to all drugs
How do you prevent small strongyles/Cyathostomins infection?
Treat sick animals
Clean up feces
Do not overstock
What is the most pathogenic large strongyle?
S. vulgaris larva
What part of the body is affected by Dictyocaulus arnfieldi?
lungs
What is the major host for Dictyocaulus arnfieldi?
Donkeys
In horse, Dictyocaulus arnfieldi adults do not reach ________ _________ and __________.
Do not reach SEXUAL MATURITY and PATENCY
You find 8 cm long slender nematodes in the bronchii of a horse. What parasite is it most likely to be?
Dictyocaulus arnfieldi
What stage of Dictyocaulus arnfieldi is found in feces?
L1
Where would you find adult Dictyocaulus arnfieldi laying eggs containing L1?
Bronchii
Dictyocaulus arnfieldi causes what clinical signs in Donkeys?
none
What clinical signs does Dictyocaulus arnfieldi cause in horses?
chronic productive cough
How do you diagnose Dictyocaulus arnfieldi?
Find L1 in fresh feces or lung washings
How do you prevent Dictyocaulus arnfieldi infection in areas where it is endemic?
Separate horses and donkeys into different pastures
What parasites belong to superfamily Filaroidea?
Setaria equina and Onchocerca cervicalis
Setaria equina and Onchocerca cervicalis have a/an ___________ lifecycle with _______ infective stage.
Indirect. L3 infective stage.
What circulates in the blood of Setaria equina and Onchocerca cervicalis?
mff (microfilaria)
Where do Onchocerca cervicalis mff accumulate?
In dermal connective tissues
Describe adult Setaria equina worms.
Long, slender, 12 cms long
Where would you find adult Setaria equina worms?
In the peritoneal cavity
What nematode would you recover from the peritoneum of a horse?
Setaria equina
Onchocerca cervicalis worms are _________ cm long
6 cm
Onchocerca cervicalis uses _________ as its intermediate host.
Culicoides spp.
Setaria equina uses _________ as its intermediate host.
Mosquitos
You find an adult nematode coiled into the tissue nodules of deep connective tissue. More specifically, the ligamentum nuchae. What parasite is this?
Onchocerca cervicalis