5. Dogs and Cats - Helminths + Ascarids Flashcards
What is the epidemiology/ecology of T. canis
Most common parasite in dogs in canada with global distribution, candid definitive hosts (including wilds), prevalence and intensity highest in young (<6mo)
Eggs survive months to years in enviro
wide range of vertebrate paratenic hosts
zoonotic: people are accidental paratenic hosts
What is somatic migration
hepatotracheal migration into wherever to hang out as a larvae
What is transplacental and transmission def? What about transmammary transmission>
Can cross into the placenta and infect puppies
Can transfer from mammary glands to offspring when they’re nursing
How do dogs greater than 6 months of age become infect and how does it travel?
They are ingested, somantically migrate as larvae in tissues and will migrate across the placenta and into the fetal liver.
after birth, they complete the typically hepato-tracheal migration to develop as patent infections. Prenatally infected pups can ched eggs at 2-3wks old and subsequent litters can be infected.
Transmammary only occurs if female newlty infected in late pregnancy
What is the lifecycle of toxocara canis at any age?
Adults will shed the egg with embryo’s into the environment and they will spend 2-8wks in enviro before rodents, birds or livestock ingest it. This becomes a vertebrate paratenic host with L3 in tissues
The dogs then eat the mouse or infected hosts and the larvae will the migrate through the mucosal surface of the intestine and repeats
prepatent period is 4 wks (mucosal)
How can we diagnose toxocara canis? What are clinical signs?
Dx - fecal float, fecal Ag, or fecal PCR
large adult worms in vomit or stool
Eggs in females
Clinical signs (puppies)
generally asymptomatic, pot belly, poor growth, diarrhea, resp signs, seizures and death(rare)
What is the MOST common way for dogs to become infected with toxocara canis
transplacental
What is the epidemiology/ecology of Toxocara cati?
most commong parasite in cats in canada
global distribution
feline as DH - prevalence and intensity in young
wide range of vertebrate paratenic hosts
people MAY be accidental paratenic hosts
eggs survive months-yrs in envir
How are cats <6 mo affected from T. cati? How long in the prepatent period?
Affected by hepatotracheal migration
PPP 8wk
spends 2-4wks in enfiro
How do infected adult female cats infect their offspring with T. cati?
kittens infected by transmammary route when female infected in late pregnancy or early action
larvae shed in milk throughout entire lactation
patent as young as 6wks of age
How are cats of any age infected with T. cati?
PPP 6wks (mucosal)
Eggs/embryo in feces > L1-L3 inside egg > eggs will L3 eaten by vertebrate paratenic hose with L3 in tissues > mucosal M > adults defecate it out
How can we diagnose T. cati, what are the signs of it?
Fecal float, Ab or PCR
Lg adult worms in vomut or stool
eggs in female
Clin signs (kittens)
Often asymptomatic; less severe than T.canis
pot belly, poor growth and coats, diarrhea
resp signs
Seizures/death (rare
What is the epidemiology/ecology of toxascaris leonina?
global distribution (including north of 60N)
CANID and felid DH (wildlife too) - prevalence and intensity highest in young
wide range of vertebrate paratenic hosts
not zoonot, eggs can survive months to years in enviro *free tolerant
WHat is the lifecycle of toxascaris leonina and it’s PPP. Is it the same in cats/dogs
PPP 8-10wk
Adults shed in feces with fertilized egg, spends 1-4 wks in enviro as L1-L3 inside egg. L3 eggs either get ingested to ingested by paratenic host in which it then spreads by mucosal migration
Same by cats/dogs
How can we diagnose toxascaris leonina? Slinical signs?
fecal float, Ag, or fecal PCR
lg adult worms in vomit/stool
eggs in females
Often asymptomatic; less severe than T. canis
