5- Stephanurus, Heterakis and Spirurids

8/12/2019 5- Stephanurus, Heterakis and Spirurids

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Stephanuridae

Parasites of kidney and

perirenal tissues


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Stephanurus dentatuskidney worm

Buccal capsule cup-

shaped and directed

straight forward with 6-

10 triangular teeth atthe base of the buccal

cavity


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Parasi tes o f renal andperirenal t issues

(aberrant ly, axial

musculature and sp inal

canal) of sw ine.Earthworm s serve as

facu ltat ive intermediate

hos ts


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L IFE CYCLE

Preparasitic development from

egg to L3 is typically strongyloid,

though earthworms may intervene

as transport hosts. There arethree modes of infection: by

ingestion of the free L3s (A),

ingestion of earthworms

carrying L3s (B), and skin

penetration by L3s (C).


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L IFE CYCLE

INGESTION

Ingested larvae exsheath in theintestine (D), enter lymphatic

vessels and pass to the

mesenteric lymph nodes where

the first molt occurs. Molting larvae

can be found in the nodes

anywhere from 1 to 9 days afterinfection. They continue on to the

liver (E), where the final molt takes

place. Following ingestion of

infected earthworm transport

hosts, L3s are released in the gut

as the earthworm is digested. Thereleased L3s migrate to the liver

as described above.
http://cal.vet.upenn.edu/projects/merial/_vti_bin/shtml.exe/Strongls/strong_3a2.htm/map


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L IFE CYCLE

SKIN

PENETRATION

Larvae infectingpigs via skin

penetration probably

molt to L4s in

subcutaneous

tissues and reach

the liver via the

lungs (H) andsystemic circulation

(I).
http://cal.vet.upenn.edu/projects/merial/_vti_bin/shtml.exe/Strongls/strong_3a3.htm/maphttp://cal.vet.upenn.edu/projects/merial/_vti_bin/shtml.exe/Strongls/strong_3a3.htm/map


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L IFE CYCLE

SKIN

PENETRATION

Occasionally,abberrant migration

occurs with worms

ending up in the

pancreas (G), muscle,and other organs of

the host where they

are trapped by

encapsulation andnever reach the

perirenal area.
http://cal.vet.upenn.edu/projects/merial/_vti_bin/shtml.exe/Strongls/strong_3a3.htm/map


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The prepatent period

ranges from 6 to 19

months and adul t

worm s have a

longevi ty of about two

years .


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There are repo rts in the

l i terature support ing acase for transm ission

of th is nematode to

piglets in utero.


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Stephanurus dentatuslife cycle features

Is direct and a long period of migration occurs, with a

prepatent period of at least 6 months. Many tissues may beinvaded prior to the adults locating in the renal area.


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Stephanurusadults in urethral cyst


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Stephanurusliver damage

The predominant ( necrotic abscesses and fibrosis)

produced occur in the liver during larval migrations. Other

tissues may also be involved.


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The infection is a herd problem and the

general picture is one of lack of growth andwasting in the pig herd.


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Stephanurussalient points

The major problem associated with S. dentatus

infections is condemnation at slaughter. Rx -Fenbendazole, ivermectin, levamisole(adults only)


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At post mortem

Decomposition takes place rapidly in animals that have

died from the results of this infection.


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Stephanurus dentatuseggs ( 100u x 60u)

Rarely if ever used in diagnosis, they are found in urine


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Since patency of S. dentatus does notusuall y occur unti l animals are 2 years

old a policy of gilts-only breeding in

which gil ts are bred only once and then

sold before kidney worms develop to

matur i ty is advocated.


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Fam i ly Syngam idae

With teeth and the buccal capsu le is

cup-shaped.


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Fam i ly Syngam idaeInc ludes the genera:

1 .Syngamus

2. Mammomonogamus

3. Cyathostoma (no t Cyathostomum )

A l l 3 have large buccal capsules, and

male and females o f Syngamus and

Mammomonogamus are permanent lyfused in copu la.

Earthworm serve as intemediate hos ts.


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Syngamus trachea

gapewo rm

Hatch ing may no t occu r. Infect ion occu rs

on ingested of the egg or free infect ive

larvae. The in fect ive larvae may beswal lowed by earthworm s, snai ls , slug s,

f lies and other ar thropods and become

encysted and l ive in these IH for severalmon ths o r years.


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Mammomonogamus- are in copu lo

They are parasi tes o f the trachea and

nasal s inuses of mammals


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Cyathos toma (no t Cyathos tomum )

-Not permanent ly in copulo

- occu rs in the trachea and bronchi

and in some cases in th e nasal and orb i talcavi t ies of geese, ducks , swans and gu l ls .


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Stomach worms

Three species of stomach worms commonly occur in

swine:

a. Hyostrongylus rubidus: red stomach

worm ( a trichostrongyle)

b. Ascarops strongyli na: thick stomach

worm ( a spirurid)

c. Physocephalus sexalatus: thick

stomach worm ( a spirurid


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Hyostrongylus rubidus: eggs

Diagnosis of this infection by finding eggs in the

feces is difficult since they are similar to Oesophagostomumeggs.Cultures can be made and 3rdstage larva identified. Pathology

varies from hyperemia to eroded areas of ulcers. The occurrence

of clinical disease due to these infections is questionable


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Physocephalus eggs:

Thick-walled, larvated, spiruroid type eggs. (

22

26u x 41

45 u)Ascarops

eggs may be slightlysmaller (3439u x 1517 u) but are difficult to

distinguish from Physocephalus


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Thick stomach worms: in mucosa of stomach

Pathology rare, may cause gastritis with

pseudomembrane formation


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Swine stomach worms: salient points

Life cycle are of trichostrongyle and spiruroidtypes, worms are common in pastured swine. Rx

Hyostrongylus(TBZ, levamisole, dichlorvos);

spiruroids (dichlorovos).


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Gongylonemaegg( 5070u x 2537 u)

Thick-walled, larvated egg, spiruroid type egg,larger than stomach worm eggs.


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Gongylonemaadult in tongue of pig

Non-pathogenic, life cycle of spiruroid type,

may also occur in mucosa of the esophagus.


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ORDER SPIRURIDA

(characterized by having microfilaria and

using arthropods as intermediate hosts)


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Dirof i lar ia imm it is(dog heartworm)


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Dirofilalria (adult in blood smear

and a nodule in lungs)


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Adult Dirofilaria in the heart


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Trichinella

Trich inel la sp iralis(causes trichinosis

of humans, rats, pigs and other flesh

eating animals)


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Trichinella



eating animals)


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Trichinella in muscle, juvenile

encysted in muscle under

compound microscope.


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Trichinella



eating animals)


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Trichinella spiralis


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Trichinella



eating animals)


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Onchocerca volvulus cysts


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onchocercoma

X- Section of onchocercoma


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Brugia(similar to Wuchereria) which

causes elephantiasis


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Adult

female

Brugia

Adult

male

Brugia


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Adult

Brugia


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Placentonemafrom whale

M th h hi di (67 110 40 65 )


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Macrocanthorynchus hi rudinaceuseggs (67110u x 4065u)

Thick-shelled, dark brown, football-shaped

M Hirudinaceus nodules on serosal surface of


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M. Hirudinaceusnodules on serosal surface of

pig small intestines.

They are due to the proboscis attachment.

Generally non-pathogenic, may perforate gut

M. Hirudinaceusadults attached to small intestines


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They can be differentiated from ascarids by presence of

proboscis, and wrinkled sometimes flat appearance


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Head wd proboscis

extended


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Close up of

acanthocephalan head


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Acanthocephala

feeding


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Nematodes in the esophagus

Gongylonema spp


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Gongylonema spp

Lesion: ruminantesophagus

Adult: showing

cuticular plaques

Spirocerca lupi eggs


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p p gg

S. lupi adult


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S. lupi adult


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Associated lesions

Pulmonary hypertrophic osteoarthropathy

Stomach, rumen or abomasum


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Stomach, rumen or abomasum

Habronemasp:(Draschia similar)

typical lesion

Physalopteraspp: eggs


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y p spp eggs

Physalopteraspp: adult


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y p pp

head Male


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Morpholog y Physalopteraspp: (diagram of head)


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p gy y p pp ( g )

Lesion of Physaloptera spp: (stomach of dog)


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Lesion of Physalopteraspp: (stomach of dog)

Ollu lanus tr icus pis


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p

Adult male


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Ollu lanus tr icus pis


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Adult male


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Dioctophymatoidea

Dogs and wild

carnivores:

Dioctophyma renale

Dictyophyme renale adult can


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measure up to 60 cm in length

Adult worm in situ. Note

that the tissue of the

kid h b


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kidney has been

destroyed.

Egg found in the urine

(compare to P. (C.) pl ica,

which is also found in


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which is also found in

the urine).

This egg measures 65 X42 m.


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THANK YOU VERY MUCH

Documents

5- Stephanurus, Heterakis and Spirurids