Para: Exam 4 Labs & Kahoot

Males, females

Dirofilaria immitis Adults

-The _____ are shorter & their tail is coiled

-The ______ are longer & their tail is straight.

*Infects canids (DH) with mosquitoes as IH

Microfiliariae

Stage of Dirofiliria immitis that are released from adult females & circulate in the blood

*Can be detected in blood smears from an infected canine host

Acanthocheilonema reconditum

Does the following describe Dirofilaria immitis & acanthocheilonema reconditum?

-Curved body, blunt head, curved, "button hook" tail

-Progressive motility

-Usually few in #

-Narrower than RBC

Dirofilaria immitis

Does the following describe Dirofilaria immitis & acanthocheilonema reconditum?

-Straight body & tail, tapered head

-Stationary motility

-Usually many in # in infections

-Wider than RBCS

Modified Knott test

Microfilariae concentration test that's recommended by for

evaluating morphology to differentiate D. immitis from Acanthocheilonema reconditum

SNAP test

ELISA that detects Heartworm antigen (antigen-capture)

-Can provide somewhat quantitative results

Onchocerca cervicalis

Filariid that infects equids (DH) with biting midges as the IH

-Adults (slender & white) are located in the nuchal ligament

Onchocerca cervicalis

Filiariid in equine whose microfiliariae can be found in the ocular conjunctiva, dermis, & connective tissues

Dracunculus insignis

Guinea worm that infects canids (mainly) & cats with copepods being the IH

-Long, slender & white adult females often protrude from nodular lesions of subcutaneous tissue of limbs and L1s are released into water

Physaloptera

Nematode that infects canids (DH), cats, racoons, etc.

-Have a prominent cuticular collar (cephalic alae) around the mouth

-Adults may be expelled in vomitus or embedded in stomach mucosa at necropsy

Physaloptera

Nematode in dogs & cats with thick shelled eggs that contain L1 larvae

-Length of eggs is 2x their width

*Best recovered using a fecal sedimentation technique due to their high density; adults found on endoscopy or in vomit

Spirocerca lupi

Nematode that infects the esophagus of canids (mainly) & felines

-IH = coprophagous beetles

-Migrating juveniles may be found within nodules in the wall of the aorta

Draschia, Habronema

Stomach nodule that infects equids (DH) with musca domestica (House fly) & Stomoxys calcitrans (stable fly)

-Adults form nodules in the stomach

L3

_____ (stage larvae) of Draschia & Habronema spp. are deposited by flies on various parts of the body & can be associated with summer sores (cutaneous habronemiasis).

Margo plicatus, glandular stomach

Nematode Nodules in Equine Stomach Vary by Location:

-Draschia forms in the _____ _____.

-Habronema forms in the ____ _____.

Oxyuris equi

Equine pinworms that infect the colon

-Adults females are stout with a large esophagus that has a prominent esophageal bulb; may be passed in the feces

-Eggs are laid in the perineal/anal skin area

Scotch tape method

Best method for detecting Oxyuris equi eggs (ovoid, yellowish, thick shelled, flattened, operculated)

Setaria equina

Nonpathogenic filariid that infects equids (DH) with mosquitoes (IH)

-Adults are large, long, & white that are found in the peritoneal cavity & pleural cavity

-Microfilariae are shed by adult females & found in the blood

Gnathostoma

Nematodes that infects the stomach of mammals (including humans)

-1st IH: freshwater copepods

-2nd IH: Freshwater fish & amphibians

-Adults & larvae have cuticular spines along the anterior portion of the body with a prominent cephalic bulb

-Unembryonated, operculated eggs are passed in feces

Haemonchus

Largest of the abomasal trichostrongyle

-Small buccal cavity

-Common name: Barber pole (female worms coil/wrap their uterus/ovaries around their intestine)

Contortus, Placei

Haemonchus Species:

-_____ = infects small ruminants

-_____ = infects cattle

FAMACHA

Eye chart is used only for assessing the severity of H. contortus-induced anemia in small ruminants & camelids

Adults, L4

What stages of Haemonchus contortus are aggressive blood feeders that can cause anemia in small ruminants?

Haemonchus contortus

What abomasal, male nematode is this based on its copulatory bursa and spicules (arrow)?

Ostertagia ostertagi

Causes cobblestone like lesions on the mucosal surface of the abomasum in cattle (DH)

-Tiny buccal cavity with cephalic papillae

Trichostrongylus

Smallest abomasal nematode that infects large/small ruminants & horses

*Have a small buccal capsule

Colubriformis, Axei

Trichostrongylus Species:

-T. _____ = major species found in the SI of small ruminants

-T. ____ = infects abomasum of cattle & stomach of horses

Cooperia

Ruminant strongyle with a characteristic cephalic vesicle/swelling at its anterior end

-Found in the SI of large & small ruminants

-Similar in size to Trichostrongylus spp.

Oesophagostomum

Large bursate ruminant strongyle that forms nodules in large intestine of small & large ruminants

-AKA nodular worm

*Characteristic cephalic vesicle surrounding a cylindrical buccal capsule

Columbianum, venulosum

Oesophagostomum Species:

-O. _____= occurs in sheep & goats

-O. ______ = occurs in cattle, sheep, & goats

Ruminant strongyle type eggs

Identify these thin shelled, ellipsoidal, greyish eggs found in large & small ruminants

Bunostomum

Hookworm species that infects the small intestine of ruminants with chitinous cutting plates

-Eggs have thickened shells, more bluntly rounded ends, & more darkly pigmented cells compared to strongyle-type eggs

L3

The Baermann technique (following Coproculture of eggs) identifies what larval stage of Ruminant & Equine strongyles based on morphology?

*Retained cuticle gives this larvae stage a crinkled appearance

Nematodirus

Ruminant strongyle that infects the SI of small/large ruminants & passes large non-"strongyle type eggs"

-Adult characteristics: inflated cuticle at anterior end, long/slender spicules in males

Strongylus vulgaris

Large equine strongyle that is smaller than other strongylus species but the most pathogenic

-Has 2 rounded ear-shaped teeth

Strongylus equinus

Large equine strongyle that has 3 teeth (1 large dorsal, 2 small subventral)

-Ovoid buccal cavity with external & internal leaf-crowns

Strongylus edentatus

Large equine strongyle that has no teeth

-Ovoid buccal cavity with external & internal leaf-crowns

Cyathostomes

Small equine strongyle that infects the cecum & colon

-Has a well-developed buccal cavity that's more cylindrical in shape than the ovoid buccal cavity of the large strongyles

-Have external & internal leaf-crowns

*Larvae can be recovered using a Baermann technique

Equine strongyle type eggs (includes large & small)

Identify these thin shelled, ellipsoidal, a grey colored eggs in equine

Phlebotomum

Bunostomum species that infects the SI of wild & domestic ruminants

-Has chitinous cutting plates & multiple sub-ventral lancets

Trigonocephalum

Bunostomum species that infects the SI of sheep, goats, alpaca, & llamas

Ancylostomum caninum

Most pathogenic hookworm species in dogs

-Very aggressive blood feeders with 3 pairs of teeth that infect the SI

-Transmammary transmission = most significant route of infection

Ancylostomum tubaeforme

Hookworm species with 3 pairs of teeth that infects the SI of felids only

Ancylostomum braziliense

Hookworm species with 1 pair of teeth that infects the SI of dogs & cats

-Percutaneous route of transmission = most significant

*Associated with Cutaneous larva migrans in humans

Small intestine

What part of the DH do Anyclostomum spp. infect?

*Bloodfeeders that attach to the mucosa

Uncinaria stenocephala

Hookworm with chitinous cutting plates that infects the SI of canids & felids

-more likely to be found in cooler regions of the US

Hookworm eggs

Identify these thin shelled, ovoid, containing morula with 2-8 cells

-Found in dogs & cats

Strongyloides

AKA threadworms, infect SI of multiple DH (depending on spp)

-Parthenogenetic females with long filariform esophagus, no parasitic males

*Females seen in mucosal scrapings of intestines

Stercoralis

Strongyloides species that infects the SI of dogs, cats, & humans

-Has L1 stages (rhabditiform larvae) with a club shaped esophagus & posterior bulb that hatch within the DH & are passed directly in feces

-L1s also have a characteristic genital primoridum

L3

What is the infective stage in all Strongyloides spp?

-Has a filariform esophagus (longer & thinner than rhabditiform esophagus)

*Does not have a narrow section or a bulb

Papillosus, Westeri

Strongyloides Species:

-S. ____ = ruminants

-S. ____ = equids

*Strongyloides eggs are smaller than strongyle-type eggs

Gordian worms

AKA Horsehair worms

-Larval stages develop in arthropods (crickets, grasshoppers)

-Adult stages are free-living

Angiostrongylus cantonensis

AKA rat lungworm

-Causes eosinophilic meningitis in humans & is prevalent in Southeast Asia and tropical Pacific islands

Toxascaris leonina

Roundworm that infects the SI of domestic/wild felids & canids

-Cervical alae is similar to that of Toxocara canis

-Eggs are ovoid with a smooth outer shell & more spacious interior compared to eggs of Toxocara cati & canis

Toxocara cati

Roundworm that infects the SI of wild/domestic felids

-Prominent, arrowhead-like cervical alae

-Eggs are ovoid with a bumpy outer surface with a less spacious interior compared to Toxascaris leonina

Toxocara canis

Roundworm that infects the SI of domestic/wild canids

-Cervical alae are similar to Toxascaris leonina

*Ovoid eggs with a bumpy outer surface & less spacious interior than to Toxascaris leonina

*Transplacental transmission is a significant transmission route

Baylisascaris procyonis

Roundworm that infects SI of racoons & rarely domestic canids

-Eggs are subspherical & brown with a finely pitted outer shell, & contain a single cell that doesn't fill the egg

*Can lead to neural larva migrans & ocular larva migrans in humans

Parascaris univalens

Roundworms that infect the SI of equids

-Eggs are almost round with a golden brown, thick pitted shell

-Sometimes, eggs lack dark rough protein coat

Ascaris suum

Roundworm that infects the SI of swine

-Eggs are ovoid, golden brown, thick shelled with bumpy exterior

*Eggs are sticky, very resistant, & can remain infective for many years; zoonotic risk

Heterakis gallinarum

Roundworm that infects the ceca of galliform birds 

-Adults are small white worms, while eggs are ellipsoid with a thick smooth shell containing a single cell that fills the egg

Ascaridia galli

Roundworm that infects the SI of Galliform birds

-Adults are large white worms, while eggs are ovoid with a thick smooth shell

-Eggs are Larger & more ovoid than Heterakis gallinarum

Trichuris vulpis

Whipworms that infect the cecum & colon of domestic/wild canids

-Adults have a long stichosome esophagus composed of stichocytes

-Eggs are football-shaped with bipolar plugs & a smooth surface

Trichuris ovis

Whipworm that infects the cecum & colon of domestic/wild ruminants

-Adult males have a spined spicule

-Eggs have a football shape & bipolar plugs

Capillarids

Very small, thin nematodes with a stichosome esophagus typical of Enoplida

-Difficult to see grossly at necropsy

-Eggs are more barrel shaped (sides are more parallel) with a rough surface compared to Trichuris eggs

-Eggs may be in feces or urine depending on the type

*Ex: Eucoleus, Pearsonema

False (not expected in urine sediment because it is a respiratory parasite)

True or False: You would expect to see Eucoleus aerophilus in a urine sediment.

Capillarid type eggs

Identify what type of nematode eggs these are.

-Present in quail

*Bipolar plugged egg in histo sections can aid in the diagnosis of infection

Trichinella spiralis

Trichinelloidea that infects the SI in a wide range of mammalian hosts (including humans) & some avian spp.

-Adults are very small with a stichosome esophagus

-Nurse cells encapsulate & protect the L1s in muscle

Dictyocaulus

Group of Trichostrongyloidea lungworms that infect the bronchioles, bronchi, & trachea

*Adults are plain, long, thin worms

-Baermann technique to recover L1 (blunt end, brown intestinal granules, & button at mouth)

Muellerius capillaris

Lungworm that infects the bronchioles & lung parenchyma of sheep & goats

-L4 are found in lung parenchyma & form nodules where adults develop

-L1 have a wavy, pointed tail with dorsal spine & are found in feces --> Baermann technique

Aelurostrongylus abstrusus

Lungworm that infects the bronchioles, lung parenchyma, & alveoli of domestic/wild felids

-Eggs can be found in sputum or transtracheal washes

-Characteristic tail of L1 with an S-shaped bend & dorsal spine

Oslerus (Filaroides) osleri

Metastrongyloidea (lungworm) that forms nodules in the trachea & bronchi of domestic/wild canids

-Not often found in the lungs but can be confirmed by bronchoscopy as lesions observed by bronchoscope are pathognomonic

Metastrongylus

Are Trichostrongyloidea or Metastrongylus the lungworm superfamily that infect the bronchi & bronchioles in swine?

-Larvated eggs passed in feces; earthworms are IH & harbor the infective L3 stage (indirect life cycle)

Ollulanus triscuspis

Trichostrongylid nematode that infects the gastric mucosa of the stomach in domestic/wild felids

-Associated with chronic cases of vomiting in the absence of other nematodes (i.e. Physaloptera)

*Life cycle is direct with the transmission of L3s are expelled in the vomitus that are then ingested

-Females are ovoviviparous, autoinfection is possible

-Adults have 3 unique projections called tubercles

Dictyocaulus viviparous

This lungworm of cattle has a direct LC and sheds L1s in fresh feces that are isolated on a Baermann

Ascaridia galli, heterakis gallinarum, ascaris suum

Earthworms serve as PH for these 3 roundworms by bioaccumulating infectious larvae/eggs within soil

Strongyloides ransomi and westerni

What 2 Strongyloides species is transmammary transmission is important in their epidemiology?

Trichinella spiralis

L1s of this nematode infect striated muscle cells of warm blooded animals & the adults reside in their SI

Strongyloides stercoralis, Aelurostrongylus abstrusus, Dictyocaulus filaria

Baermann technique is used to isolate the L1s of which of these nematodes:

-Strongyloides papillosus

-Strongyloides stercoralis

-Aelurostrongylus abstrusus

-Dictyocaulus filaria

Baylisascaris procyonis

Racoons should be handled with caution because of the zoonotic risk of this nematode & associated with neural larval migrans

False

True or False; Domestic dogs can't be a DH of Baylisascaris procyonis & wouldn't be a source of zoonotic transmission.

Dioctophyme renale

Giant kidney worm with adults found in the kidneys

Strongyloides stercoralis

In addition to Ancylostoma braziliense (hookworm), this nematode is also responsible for cutaneous larval migrans in people

*Walking around barefoot

Bear

Zoonoses with Trichinella spiralis occur primarily in the US from consuming undercooked meat of this host

Sheep, goats

What are the DH of these lungworms (Infect respiratory tract):

-Dictylocaulus filaria

-Muellerius capillaris

Strongyloides stercoralis

Autoinfection with this nematode in canids can be associated with severe disease

*Can recolonize in the SI

Toxocara canis

A puppy with these symptoms likely is infected with what parasite:

-Ovoid spherical eggs with a bumpy outer edge & dark single cell within

-Potbellied appearance

-Ascarid worms expelled in vomitus or feces

-Small intestinal obstruction

Toxocara cati

A kitten with these symptoms likely is infected with what parasite:

-Ovoid spherical eggs with a bumpy outer edge & dark single cell within

-Potbellied appearance

-Ascarid worms expelled in vomitus or feces

-Small intestinal obstruction

Ascaris suum

What pig nematode is associated with fibrotic areas in the liver tissue known as "milk spots"?

Strongyloides tumefaciens

This nematode infects the SI of most hosts but in cats infections consist of large intestinal nodules

True

True or False: Rodents harboring L3s of Toxocara spp & Toxocaris Leonina can serve as PH if they're ingested by a hsot.

Oslerus (Filaroides) osleri

Tracheal nodules observed by bronchoscopy in a canid are pathognomonic for infection with ...

Pilobolus

This fungus is important in the dispersal larvae of Dictylocaulus viviparus from a cow paddy

Toxocara canis, toxocara cati

What 2 ascarids are associated with visceral larval migrans or ocular larva migrans

True

True or False: Peroral transmission is a route of entry for Trichuris into a new host.

False

True or False: Trichuris spp. infect the esophagus of their host.

True

True or False: Trichuris is commonly called whipworms.

True

True or False: Trichuris eggs are football-shaped with 2 polar plugs at either ends.

False (only find parasitic females)

True or False: At necropsy, male & female adults of Strongyloides ransomi could be recovered from mucosal scrapings of the duodenum of a pig.

Toxocara canis, toxascaris leonina, Baylisascaris procyonis

Which of these nematodes have eggs that can be found in a fecal flotation of an infected canine host:

-Strongyloides westeri

-Toxocara canis

-Toxascaris leonina

-Baylisascaris procyonis

Cattle, sheep

Nematodirus by Species:

-N. helvetianus = infects cattle

-N. battus = infects sheep