Parasitology Exam 2

Nematoda phylum common name

Roundworm

where do free living nematodes live

freshwater, saltwater, soil

what is a major cause of animal, plant, and human disease

nematodes

copulatory bursa

lateral flat expansion at posterior region of male nematodes

bursate nematodes

hookworm, strongyles, trichostrongyles

nonbursate nematodes

roundworm, filaroides, pinworm, trichinelloid

What is on the left

Copulatory bursa of male nematode

What is on the right

Male nematode without copulatory bursa

what are the most important parts of a nematode

digestive and reproductive

where is the digestive system of a nematode

digestive tube extends from the mouth to the anus and ends at the rectum or cloaca

do nematodes have a circulatory or respiratory system

no

what kind of mouthparts do nematodes have

leaf crown, numerous papillae

what kind of reproductive parts do male nematodes have?

tubular testes

what kind of reproductive parts do female nematodes have?

uterus

what are the 4 kinds of nematode eggs

ascarid, trichostrongyle/strongyle, spirurid, trichinelloid

ascarid egg

round, yellow/brown, single cell stage inside

trichostrongyle/strongyle egg

thin wall, oval, morula with multiple cells inside

spirurid egg

small, oval, thick shell, first stage larva inside, further developed

trichinelloid egg

oval, brown, thick shell, operculum plugs at each end, single cell inside

What kind of egg is this

Ascarid egg

What kind of egg is this

Trichostrongyle egg

What kind of egg is this

Spirurid egg

What kind of egg is this

Trichinelloid egg

Oviparous egg

egg hatches after it has been laid, unembryonated egg

Ovoviviparous egg

egg hatches within female before being laid or shortly after

larviparous

female retains egg in uterus and give birth to larvae

what is the normal life cycle of a nematode

adult female produces egg or larva, L1 emerges and molts into L2, L2 molts into L3, L4, L5 within definitive host, L5 migrates into predilection site and develops into mature adult, male and female adult worms breed

which is the infective stage larva of nematodes

L3

which is the immature/preadult nematode stage

L5

direct L3 nematode larva

larva lives in environment

indirect L3 nematode larva

larva is in intermediate host

which stages of nematode larva are inside infected definitive host

L4 and L5

what must L4 and L5 larva do after entering the definitive host

migrate to predilection site

direct life cycle

parasite does not need an intermediate host to complete life cycle

Indirect life cycle

larva needs an intermediate host to finish life cycle

what is the exception to the L3 infective stage larva

some nematodes produce eggs that do not hatch, the eggs contain larva inside that is infective

Prepatent period

the time from infection to diagnostic stage

how are worms diagnosed

by using a fecal sample

how long is the prepatent period for heartworm

6 months

Spirocerca lupi

esophageal worm

what is the prepatent period of Spirocerca lupi

6 months

how does a host get infected with Spirocerca lupi

Dung beetle goes into stool and gets infected, parasite becomes L3, definitive host eats dung beetle intermediate host and becomes infected

which life cycle does Spirocerca lupi have

indirect lifecycle

what is the intermediate host for Spirocerca lupi

dung beetle

where does Spirocerca lupi migrate to after infecting the host

wall of celiac artery and thoracic aorta, develop there for 3 months, migrate to esophageal wall as adults

Physaloptera spp

Stomach worm

Where do adult Physaloptera live in the host

stomach or small intestine lumen attached to mucosa of dog and cat

what symptoms do Physaloptera cause

vomiting, anorexia, dark tarry stool

Melena

dark tarry stool, bleeding source is higher in the GI tract, normally small intestine, and blood has been digested

what does bright red stool mean

bleeding source is in the lower end of the GI tract

what is the intermediate host for Physaloptera

cockroach, beetle, cricket

what is the prepatent period for Physaloptera

56-83 days

paratenic host

host where parasite development does not occur but bridges an ecological gap in the parasite's life cycle

what is the paratenic host of Spirocerca lupi

chicken, reptile, rabbit

what is the paratenic host of Physaloptera

mice, frogs

Toxocara canis

dog roundworm

Toxocara cati

feline roundworm

Toxascaris leonine

cat and dog roundworm

what kind of nematode is Toxocara canis, Toxocara cati, Toxascaris leonine

ascarid

is Toxocara canis, Toxocara cati, Toxascaris leonine zoonotic

yes

where is Toxocara canis, Toxocara cati, Toxascaris leonine located in the host

don't attach to intestine, free floating in small intestine

what are the symptoms of Toxocara canis, Toxocara cati, Toxascaris leonine

vomiting, diarrhea, coughing, potbelly appearance

what kind of eggs do Physaloptera have

Spirurid

What is the difference between Toxocara and Toxascaris eggs

Toxocara have rough pitted outer shell while Toxascaris have a smooth outer shell

Toxocara canis, Toxocara cati, Toxacaris leonine life cycle

eggs in host feces, embryonate on ground until L3 larvae, larvae ingested by new host, L3 released from egg, larvae migrate to tissues and lungs, L3 larvae coughed and swallowed into GI tract, L3 larvae develop into adult in small intestine

what kind of transmission route does Toxocara canis, Toxocara cati

fecal oral transmission

how long is the prepatent period for roundworms

3-4 weeks, 21-35 days

what is the paratenic host for Toxocara canis, Toxocara cati, Toascaris leonine

rodent

How does Toxascaris leonine infect the host

ingestion of rodent paratenic host

Visceral larval migrans

condition where Toxocara canis, Toxocara cati, or Toxascaris leonine infects human host and migrates to various organs

Ocular Larval Migrans

condition where Toxocara canis, Toxocara cati, Toxascaris leonine infects a host and migrates to the eyes

how do you diagnose Toxocara canis, Toxocara cati, Toxascaris leonine

fecal float identification of eggs, antigen ELISA to visualize adult worms

how do you treat and prevent Toxocara canis, Toxocara cati, Toxascaris leonine

deworming through strongid, ivermectin, panacur, drontal, hand washing

Baylisascaris procyonis

Racoon roundworm

is Baylisascaris procyonis zoonotic

yes

Ancylostoma spp

canine and feline hookworm

Ancylostoma caninum

canine hookworm

Ancylostoma tubaeforme

Feline hookworm

Uncinaria stenocephala

Northern canine hookworm

where do Ancylostoma infect the host

attach to mucosa of small intestine using teeth

what do Ancylostoma feed on

blood using teeth

Ancylostoma life cycle

male and female attach to wall of small intestine and mate, eggs with morula passed into environment through host feces, morula develops into L1 and hatches, develops into L3 in environment, L3 ingested or penetrate skin, migrate into lungs, coughed up, swallowed, migrate to small intestine and attach

Vertical transmission

transmission of parasite from parent to offspring

how do you treat Ancylostoma

deworming through strongid for puppies and kittens, ivermectin, panacur, drontal

how do you prevent Ancylostoma

keep environment clean of feces to prevent Morula from developing, routine fecal sample testing, proper disinfectant cleaning protocols

what is the fecal sample testing recommendations for dogs and cats

4 times during first year of life, 2 times yearly after first year

Strongyloides spp

Intestinal threadworm

Strongyloides westerii

horse intestinal threadworm

which gender of Strongyloides is parasitic

female

how do Strongyloides reproduce

female produces larva without fertilization

autoinfection

parasite reinfects host right away after being passed through stool because parasite is well developed when passed in feces

Strongyloides westerii, Strongyloides spp life cycle

Female in small intestine lays egg, egg hatches in small intestine, free living larvae develop into infective L3, L3 penetrate skin and migrate to small intestine or ingested, larvae can be passed through feces

Trichuris vulpis, Trichuris ovis, Trichuris suis

whipworm

do Trichuris vulpis infect cats

rare in cats

What kind of eggs does Thricuris vulpis have

trichinelloid

Tricuris vulpis, Tricuris ovis, Tricuris suis life cycle

adult attached to cecum or colon wall in large intestine feeding on blood, pass eggs into host feces, infective L1 larva develops in egg, egg ingested by host, larva molts into adult

Enterobius vemicularis

human pinworm

Dirofilaria immitis

canine heartworm

What animals does Dirofilaria immitis parasitize

cats, dogs, ferrets

where do adult Dirofilaria immitis reside

pulmonary arteries, right ventricle