nematodes

Question 1

ascarids ID

Answer 1

large robust (cm)
lateral alea anteriror end
3 anterior lips
non larvated egg

Question 2

ascarid egg differentiation

Answer 2

toxocara
canis= dark center thick pitted shell (80um)
cati= dark center pitted shell (70um)
leonine= hyaline center smooth shell

Question 3

toxocara canis
Direct transmission (ingestion of larvated egg) puppy < 3 MONTHS OLD

Answer 3

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!*

Question 4

toxocara canis
Direct transmission (ingestion of larvated egg) dog > 3 MONTHS OLD

Answer 4

SOMATIC MIGRATION
larvae hatch at duodenum penetrate intestine wall –> systemic circulation –> heart, liver ect. ENCYST/HYPOBIOTIC
NO MATURATION
(can facilitate transplacental transmission in future)

Question 5

toxocara canis
transplacental transmission
how many days old before eggs in feces

Answer 5

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!

Question 6

toxocara canis

modes of transmission

Answer 6

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!*

Question 7

toxocara canis

what modes of transmission allow for NO MIGRATION OF LARVAE

Answer 7

Colostral transmission via bitch infected during lacation

DH ingestion of paratenic host with encysted larva

Question 8

Nematodes with Zoonosis potential

Answer 8

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

Question 9

T/F DH sheds non-larvated ascarid to env

Answer 9

T (2-3 weeks for egg to larvate)

Question 10

toxocara canis

colostral transmission

Answer 10

Bitch infected DURING LACTATION

larvae migrate to MAMMARY TISSUE, in COLOSTRUM infect puppy SI directly (NO MIGRATION)

Question 11

toxocara canis

paratenic host transmission

Answer 11

(pig sheep rodent earthworm ect.) with encysted larvae, now in stomach of DH no miration
of larvae!*

Question 12

toxocara cati

modes of transmission

Answer 12

** ingestion of paratenic host (rodent roach worm)
Lactogenic transmission
Direct transmission- tracheal migration! (always?)

Question 13

toxicara leonine

modes of transmission

Answer 13

(cat/dog)
**DIRECT TRANSMISSION NO MIGRATION!
ingestion of paratenic host
NO MIGRATION THIS SPP.

Question 14

Tx of ascarids

Answer 14

dog/cat: fenbendazole, milbemycin, moxidectin, pyrantel
(T. cati): selamectin, emodepside
Preg bitch: fenbendazole, ivermectin

Question 15

Pathogenesis of Baylisascaris infections

Answer 15

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.

Question 16

diagnosis of ascarid infections

Answer 16

fecal FLOTATION

+/- adult in feces/vomit

Question 17

Dictophyme renale IH and DH

Answer 17

IH: annelid (on crayfish) (egg–> L3)
Paratenic H: fish/fogs (L3 encyt liver/mesentery)
DH: MINK, +/- cat pig horse cattle HUMAN* KINDEY

Question 18

Spirocerca lupi IH and DH

Answer 18

IH: dung beetle (L3)
Paratenic H: ambphibian/reptile/bird (L3 encyt)
DH: canids, wild felids ESOPHGUS large nodules

Question 19

Pathogenicity of Spirocerca lupi

Answer 19

larvae: hemorage necoris anuris death abherent spondyltits
adult: esophageal obstruction aneruism neoplastic transformation, aortic stenosis anurism

Question 20

Diagnosis of Spirocerca lupi

Answer 20

FLOATATION (with high SG)
ENDOSCOPY!*
RADS( spondylitis, undulant aortic wall, mass)

Question 21

treatment of Spirocerca lup

Answer 21

Ivermectin +/- prednisolone

Doramectin

Question 22

Physoloptera rara
Physoloptera praeputialis
treatment

Answer 22

Mebendazole

pyrantel, fenbendazole, ivermectin

Question 23

Spirocerca lupi
Physoloptera rara
Physoloptera praeputialis
(eggs, IH, dxn, PPP)

Answer 23

LARVATED EGGS
IH dung beetle
fecal FLOAT with increased spec grav, endoscopy
PPP 5-6 months

Question 24

Pathogenesis of
Physoloptera rara
Physoloptera praeputialis

Answer 24

bleeding ulcers v+ weight loss melena

Question 25

Physoloptera rara

IH and DH

Answer 25

IH: Dung beetle, roach grasshopper ect.
Pt H: snake rat fog (L3 encyst)
DH: dog STOMACH and DUODENUM

Question 26

Physoloptera praeputialis

IH and DH

Answer 26

IH: Dung beetle, roach grasshopper ect.
Pt H: snake rat fog (L3 encyst)
DH: cat STOMACH

Question 27

LIfe cycle of Ollularis tricuspis

Answer 27

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

Question 28

characteristics of ascarids (toxicara spp. baylisascaris)

ID/Lifecycle/copulatory bursa/ egg

Answer 28

V LARGE 3 anterior lips
Direct cycle (larval migrations)
M: NO copulatory bursa +/- alae
egg large thick shell FLOATATION