round worms Flashcards
what is unique about the nematode (roundworm) body
epidermis covered by a cuticle
complete digestive tract (separate mouth + anus)
how many juvenile (larval) stages are there and what occurs at the end of each stage?
four
molting occurs, growth occurs before and after molting
in parasitic nematodes what is the infective stage to the definitive host?
L3
L3–>L4 once in definitive host
GI nematodes that typically acquired by ingestion of infective eggs or larvae
monoxenous
GI nematodes ingestion of infected intermeidate (or paraentenic) hosts
heteroxenous
nematodes that undergoe heptao-tracheal migration
ascarids
nematode that infects SI of swine and humans
ascaris suum
nematode that infects the SI of horses
parascaris equorum
disease that is primarily in young animals can cause respiratory signs in young pigs and foals
ascarosis
prevention by deworming and washing sows/mares prior to birthing, keeping young animals away from contaminated pastures/stalls and prophylactic pyrantel treatment
Ascarids: A. suum & P. equorum
ascaridids prepotent infections
lung and tissue for baermann test
what nematode is resistant to ivermectin an moxidectin
P. equorum
SI of mammals; monoxenous
toxocara spp
toxocara in domestic and wild canids
T. canis
toxocarain domestic and wild felids
T. cati
disease can be severe in puppies, usually subclinical or mild in kittens; symptomatic infections can occur in adult cats but rare in adult dogs
toxocariasis
T/F: Toxocara canis and Toxocara cati are zoontic; children are especially at risk
T
SI of chickens, turkeys, ducks, geese, and diverse wild birds, monoxenous; fecal-oral transmission
ascaridia galli
common round worm of domestic poultry
treatment for ascaridia galli
fenbendazole
monoxenous cecal worm of chickens, turkeys, other galliform birds
heterakis gallinarum
what serves as an intermediate host and vector for the turkey pathogen histomonas meleagridis
heterakis gallinarum
parasite of the posterior gut of arthropods and vertebrates, highly host-specific, monoxenous
oxyurids- pinworms
pinworm that descends the small colon and also large colon of equids
oxyuris equi
egg masses are glued to perianal skin; causes perianal itching
Oxyuris equine
The most common roundworm of domestic poultry
Acardidia galli
Trichinelloids (Trichuris)
whipworms
monoxenous, host-specific, cecum and colon of mammals
Trichuris larvae are in ____, adults are in _____
SI mucosa
cecum & colon
whipworm found in canids world wide
T. vulpis
whipworm found in swine worldwide common in US swine
T. suis
with heavy infections what can cause rectal prolapse in dogs
T. vulpis
heteroxenous
infected individual is both definitive and intermediate host
most human cases in US come fro eating raw or undercooked pork or bear
Trichinellosis
prevent by cooking meat to safe temperatures, careful control of pig farming, preventing scavenging by pets, don’t feed pets raw meat
Trichinelloids
treatment options for trichinella
mebendazole or albendazole
what are the 4 major groups of strongylida
- GI “hairworms” and trichostrongyloid lungworms
- large bowel stongyles and nodular worms
- hookworms
- metastrongyloid lung, vascular and neural worms
what groups of strongylida are monoxenous
groups 1-3
what group out of the strongylida is heteroxenous
group 4
most infect the abomasum or stomach
trichostrongyloids
infective larval stage of trichostrongyloids
L3
trichostrongyloid species that feed on blood
Haemonchus spp.
trichostrongyloid species that infect respiratory passages
Dictylocaulus
where is arrested development occur in trichosterongyloids
in the host L3 or L4
latent, inhibited or hypobiotic larvae
arrested larvae
importance of arrested larval development
- avoid conditions not optimal for growth/development/survival
- resumption of development of a large number at one time -can cause significant disease in host
- arrested larvae may be less susceptible to anthelmintics
most important helminth parasite of sheep and goats in USA
Haemonchus contortus
cooperia spp that infects SI of cattle
Cooperia punctata
infects bronchial tree of cattle and other ruminants
Dictyocaulus viviparus
diagnosis of trichostrongyloid lungworms
ID larvae in feces (Baermann apparatus)
diagnosis of trichostrongyloid GI worms
ID eggs in fecal sample & fecal egg count
most strongyloid worms infect the ?
large intestine
cause blood loss & damage to mucosa
Strongylus vulgaris
large strongyles of equine colon & cecum
Triodontrophorus spp
adults eat mucosal plugs and blood; larvae are non-migratory
small strongyles of equine cecum and colon
Cyathostomins
Adult Strongylus vulgaris
strongyloid of equine cecum and colon
Mass emergence of hypobiotic cyathostomin larvae causing acute onset of profuse diarrhea, sudden weight loss, pyrexia, colic, subcutaneous edema, etc. Can be fatal, especially in young animals.
larval cyathostominosis
swine kidney worm
stephanurus dentatus
life cycle of stephanurus dentatus
adult worms in renal and peripheral tissue –> eggs in urine
-swine ingested L3s or infected paratenic host (worms); percutaneous infection of L3s
-larval migration in liver and stay there for long time (primarily site infection), then when ready to go an develop into adults in the kidney and get excreted
where do syngamid worms infect
upper respiratory tract of birds and mammals
syngamid worms also referred to as
gapeworms
worm found in domestic and wild galiform birds
syngamus trachea
life cycle of syngamus trachea
birds ingest L3s infective eggs or infective paratenic host –> larvae migrate SI to liver to the lungs –> obstruct airway adults
where are hookworms mainly found
parasite of SI of mammals
paratenic host of syngamus trachea
earthworms. terrestrial mollusks, larval flies
ancylostomatoids primarily impact what species?
mainly dogs
cats
ruminants
how does ancylstomatoids infect host
L3s typically ingested or can penetrate skin
-go straight to thee lungs and climb up and get swallowed and stay in SI
-milk and SI stay and develop into adults
dog ancylstomatoids spp (hookworm) that infect dogs
ancylostoma caninum
A. braziliense
cat ancylstomatoids spp that infect cats
ancylostoma tubaeforme
A. braziliense
what is more pathogenic the dog ancylostoma spp or the feline
dog
if a dog is older than 3 months what larvae arrest in the skeletal muscle and SI wall? what happens if they are female? and when do they become activated?
A. caninum
-during pregnancy they migrate to mammary glands –> milk –> pups
-and adult hookworms can get lost from the SI are arrestely developed and pass once dewormed
hookworm of domestic ruminants, cattle
Bunostomum phlebotomum
ancylostomatoids
hookworms
hook worm species that percutaneous route of infection predominates
bunostomum spp
what parasite infect the resp tract, vascular, and nervous system of mammals
metastrongyloids
metastrongyloid lungworms of the sheep and goats
protostrongylus rufescens
muellerius capillaris
most common lungworm of cats
aelurostrongylus abstrusus
metastrongyloid lungworm of dog
what is reservoir host
crenosoma vulpis
red fox (vulpes vulpes) reservoir host
filaroides spp what stage odf lifecycle is infective?
direct life cycle
L1s are infective
two filaroides spp that infect airway of dogs
F. osleri
F. hirthi
what species of hookworm zoonotic and causes cutaneous larva migrans
A. braziliense
A. caninum
ancylostoma caninum paratenic host?
rats
syngamus trachea paratenic host
earthworms, terrestrial mollusks, larval flies
threadworm strongyloides species that infects dogs, cats, humans and other primates
S. sterorlais
treatment for mammals and birds of strongyloides spp
mammals: ivermectin
birds: tetramisole
physaloptera spp that infect the stomach of mammals, birds, reptiles and amphibians what is the intermediate host and the paratenic host
intermediate host: various insects
paratenic host: insect eating vertebrates
Dx spirurids spp
fecal sedimentation
thelazia spp that infect eye worms of mammals and birds, infect conjunctiva sac, lacrimal gland and ducts, who is the intermediate host
flies that feed on ocular secretions
habronema muscae intermediate host
housefly and stable fly
habronemiasis of equid
habronema muscae
spirocerca lupi intermediate and paratenic host
intermediate host: coprophagous beetles
paratenic host: insect-eating vertebrates
spirocerca lupi complications
aortic aneurysm or rupture with fatal hemorrhaging, esophageal sarcoma –> hypertrophic osteopathy of long bones
equine neck threadworm
O. cervicalis
