nematodes Flashcards
ascarids ID
large robust (cm)
lateral alea anteriror end
3 anterior lips
non larvated egg
ascarid egg differentiation
toxocara
canis= dark center thick pitted shell (80um)
cati= dark center pitted shell (70um)
leonine= hyaline center smooth shell
toxocara canis Direct transmission (ingestion of larvated egg) puppy < 3 MONTHS OLD
TRACHEAL MIGRATION
larvae hatch at duodenum penetrate intestine wall –> lymphatic to MESENTERIC LN
to LIVER HEART PulmA –>LUNGS
larvae MOLT in ALVEOLI coughed up trachea swallow
MOLT STOMACH L4/5 –> adult
PPP: 3-4 weeks!*
toxocara canis Direct transmission (ingestion of larvated egg) dog > 3 MONTHS OLD
SOMATIC MIGRATION
larvae hatch at duodenum penetrate intestine wall –> systemic circulation –> heart, liver ect. ENCYST/HYPOBIOTIC
NO MATURATION
(can facilitate transplacental transmission in future)
toxocara canis
transplacental transmission
how many days old before eggs in feces
pregnant bitch with encysted somatic larvae
MOBILIZE at >42d pregnancy to FETUS LIVER
LUNGS at birth (cough swallow) SI adults
EGGS IN FECES AT 23-40d old!
toxocara canis
modes of transmission
Direct ingestion (age dependent cycle)
Transplacental (bitch with encysted mobilized >d43, larvae fetal liver migrate through puppy)
Colostral (bitch infected during lactation larvae to mammary tissue, puppy stomach no migration of larvae)
Ingestion of paratenic host (pig sheep rodent) with encysted larvae, now in stomach of DH no miration
of larvae!*
toxocara canis
what modes of transmission allow for NO MIGRATION OF LARVAE
Colostral transmission via bitch infected during lacation
DH ingestion of paratenic host with encysted larva
Nematodes with Zoonosis potential
toxicara canis (paratenic host) Visceral larval migrans (VLM) - granulomatous lesions. liver/lung/brain/eye
Baylisascaris procyoris (paratenic host)- Neuro larval migrans. brain, eye ect.
Dictophyme renale (DH) in kindey - ingestion of annelid on crayfish
T/F DH sheds non-larvated ascarid to env
T (2-3 weeks for egg to larvate)
toxocara canis
colostral transmission
Bitch infected DURING LACTATION
larvae migrate to MAMMARY TISSUE, in COLOSTRUM infect puppy SI directly (NO MIGRATION)
toxocara canis
paratenic host transmission
(pig sheep rodent earthworm ect.) with encysted larvae, now in stomach of DH no miration
of larvae!*
toxocara cati
modes of transmission
** ingestion of paratenic host (rodent roach worm)
Lactogenic transmission
Direct transmission- tracheal migration! (always?)
toxicara leonine
modes of transmission
(cat/dog)
**DIRECT TRANSMISSION NO MIGRATION!
ingestion of paratenic host
NO MIGRATION THIS SPP.
Tx of ascarids
dog/cat: fenbendazole, milbemycin, moxidectin, pyrantel
(T. cati): selamectin, emodepside
Preg bitch: fenbendazole, ivermectin
Pathogenesis of Baylisascaris infections
usually none in DH +/- obstruction if heavy infxn
paratenic host with visceral larval migrans : neurologic signs (rodents primates birds highly susceptible)
respiratory disress, granulomas ect.
diagnosis of ascarid infections
fecal FLOTATION
+/- adult in feces/vomit
Dictophyme renale IH and DH
IH: annelid (on crayfish) (egg–> L3)
Paratenic H: fish/fogs (L3 encyt liver/mesentery)
DH: MINK, +/- cat pig horse cattle HUMAN* KINDEY
Spirocerca lupi IH and DH
IH: dung beetle (L3)
Paratenic H: ambphibian/reptile/bird (L3 encyt)
DH: canids, wild felids ESOPHGUS large nodules
Pathogenicity of Spirocerca lupi
larvae: hemorage necoris anuris death abherent spondyltits
adult: esophageal obstruction aneruism neoplastic transformation, aortic stenosis anurism
Diagnosis of Spirocerca lupi
FLOATATION (with high SG)
ENDOSCOPY!*
RADS( spondylitis, undulant aortic wall, mass)
treatment of Spirocerca lup
Ivermectin +/- prednisolone
Doramectin
Physoloptera rara
Physoloptera praeputialis
treatment
Mebendazole
pyrantel, fenbendazole, ivermectin
Spirocerca lupi
Physoloptera rara
Physoloptera praeputialis
(eggs, IH, dxn, PPP)
LARVATED EGGS
IH dung beetle
fecal FLOAT with increased spec grav, endoscopy
PPP 5-6 months
Pathogenesis of
Physoloptera rara
Physoloptera praeputialis
bleeding ulcers v+ weight loss melena
Physoloptera rara
IH and DH
IH: Dung beetle, roach grasshopper ect.
Pt H: snake rat fog (L3 encyst)
DH: dog STOMACH and DUODENUM
Physoloptera praeputialis
IH and DH
IH: Dung beetle, roach grasshopper ect.
Pt H: snake rat fog (L3 encyst)
DH: cat STOMACH
LIfe cycle of Ollularis tricuspis
DIRECT : Cat fox pig, +/- dog STOMACH
L3 larva released from female (egg hatched inside)
may develop into adult in same host OR
vomit L3 into env
characteristics of ascarids (toxicara spp. baylisascaris)
ID/Lifecycle/copulatory bursa/ egg
V LARGE 3 anterior lips
Direct cycle (larval migrations)
M: NO copulatory bursa +/- alae
egg large thick shell FLOATATION
