Quiz 3 Flashcards
You have a dog with microvilli and gastric gland destruction due to parasitic infestation. Which parasite is the likely causative agent?
Cryptosporidium
Which parasite has an acid fast oocyst
Cryptosporidium
Cryptosporidium can have extracellular stages in what kind of host
In hosts that are immuno-compromised (parvo pups, kittens with feLeuk)
Your client’s 8 year old son has a pet snake suspected of having Cryptosporidium. Your client read that crypto is very zoonotic - should she be worried
No, not zoonotic in snakes or lizards
What does cryptosporidium cause in snakes
Gastric hypertrophy
Identify
Cryptosporidium oocyst
How many sporocysts/sporozoites in a Cryptosporidium oocyst?
1 sporocyst/ 4 sporozoites
Where does Cryptosporidium inhabit? Is it different for immunocompromised patients?
In the microvillus border
Immuno-compromised: gallbladder, respiratory system, kidneys
Transmission of Cryptosporidium
Fecal-oral
Which food does Dr P say will give your Cypto
Oysters!
Why is cypto spread through swimming pools?
Kids go swimming with the runs (fecal-oral) and Crypto is RESISTANT TO CHLORINE
Name 4 unique ways you can get Crypto
- Oysters
- Swimming in a pool with someone who has/had Crypto
- From your boots at a dairy farm
- Mucosal scrapings (?)
T/F - Cryptosporidium can cause life threatening illness in humans
True - immuno-comprosided can have life-threatening infection (AIDS patients)
Can Crypto be passed in bird feces?
Yes! Which is how molluscs get it. We eat them raw, and then we get it
A dairy farmer calls you to look at some week old calves with projectile yellow, watery diarrhea. What do you immediately suspect>
Cryptosporidium
Can adult cows be infected with Crypto
Yes, they can act as reservoir hosts
Which type of horse is especially suceptible to Cryptosporidium
Arabian foals with SCID
A 4 year old lab comes in. He has had watery diarrhea but is otherwise healthy. Would you suspect Crypto
No - dogs are resistant unless immunocompromised
A kitten with feline leukemia is suspected of having Crypto. Paromomycin is the drug of choice for cyrptosporidum. Would you use it with this kitten?
NO! Causes acute renal failure in cats
Are pigs susceptible to Crypto?
Yes but they seldom show c/s
Spread zoonotic disease
Chronic wasting disease, with these effects, occurs in snakes as a result of
Cryptosporidium
Your client is a dairy farmer and hes had 10 cows abort in the past few weeks. What is immediately on your differentials list? (2)
Neospora caninum
Sarcocystis
Give three ways of diagnosis Cryptosporidium.
1) Acid-fast staining!
2) IHC
30 IFA/ELISA
Whats this
Cryptosporidium oocysts (acid fast stain)
Whats this
Sarcocystis (in skeletal muscle)
What’s this
Sarcocystis (in muscle)
What is the lifecycle of Sarcocystis
Indirect - obligatory 2 hosts (predator-prey life cycle)
Explain steps of Sacrocystis life cycle
1) DH (predator) sheds sporulated oocysts in feces
2) IH (prey) ingests the oocysts
3) Sporozoites released in IH.
4) Merozoites/Tachyzoites travel to and invade skeletal and caridac muscle, where they become Sarcocysts (containing bradyzoites)
5) DH eats IH –> infected with sarcocyst
6) Sarcocyst infects intestinal tissue –> Asexual repro –> Oocyst
7) Oocyst shed in feces (and cycle continues)
What’s this
Sarcocystis
What does Sarcocystis cause in cows (name 2)
ABORTION (last trimester)
Hemorrhagic vaginitis
Dyspnea, salivation, diarrhea
Decreased milk and condtion
What does Sarcocystis cause in sheep
ABORTION
Anorexia, ataxia
Encephalomyelitis?
T/F - Sarcocystis causes abortions in pigs
False (just poor growth, diarrhea, myositis)
Your client’s horse is displaying neurological signs - ataxia, head tilt, ear drooping, muscle atrophy. What is on your differential list?
Sarcocystis
(causes Equine Protozoal Myeloencephalitis)
Also Neospora hughesi
Is Sarcocystis zoonotic? How do you educate clients
Yes! - nausea, vomiting, diarrhea
DONT EAT UNDERCOOKED MEAT
What is the most common cause of neurological signs in horses (full name)
Sarcocystis neurona
What is the definitive host of Sarcocystis neurona? Intermediate hosts?
DH: opossum
IH: armadillo, skunk, racoon, sea otter, cat
T/F Along with the skunk, raccoon, and sea otters, horses can sometimes be an intermediate host of Sarcocystis neurona?
False! They are ‘dead-end’ or ‘abherrant’ hosts
What is an emerging protozoal pathogen in marine mammals
Sarcocystis neurona
How do you test for Equine Protozoal Myeloencephalitis? What is the definitive test?
- CSF testing (!) - western blot or IFAT sample
- PCR
- Necopsy - definitive test :(
What sample do you take for EPM testing?
CSF from lumbosacral region
How do you diagnosis Sarcocystis in the definitive host
(usually asymptomatic)
Fecal float (sporocysts)
How do you diagnose Sarcocystis in intermediate host
Biopsy/necropsy
- Shizonts in endothelial cells
- Sarcocysts in muscles
Two ways to control Sarcocystis
1) Burn/bury dead livestock
2) Encourage clients not to feed raw meat to pets
Who are the definitive hosts of Toxoplasma gondii
Cats!! (domestic and wild)
Where does sexual reproduction of Toxoplasma gondii occur?
Intestinal epithelium in cats —> oocysts are shed
What is the intermediate host of Toxoplasma gondii
Rats!
What is a special way Toxoplasma gondii has increased its likelihood of reaching the definitive host?
It can alter behaviour of IH (rats) to make them less fearful of cats —> predator/prey
Where does extrainestinal phase of Toxoplasma gondii exist
(faculative host only)
- Tachyzoite: parenchymal regions (*transplacental) - fast dividing
- Bradyzoite: cysts in brain, heart, skeletal muscle, eye - slow dividing
Whats this? What is a defining feature?
Toxoplasma gondii (thin cell wall!)
Is Toxoplasma gondii zoonotic?
YES! Congenital birth deformities (hydrocephalus, convulsions…etc)
Who is the faculative intermediate host of Toxoplasma gondii?
All vertebrates and birds
Which has the shortest Toxoplasma gondii PPP: ingesting cysts, sporulated oocysts or tachyzoites
Cysts have fastest PPP
T/F there is minimal shedding of T. gondii oocysts from cats
FALSE - up to 100 million are shed
T/F - it is easy to disinfect Toxoplasma gondii oocysts with bleach or UV lights
FALSE - they cant be destroyed with these products
Is cat immunity to Toxoplasma gondii lifelong?
No - can be reinfected
What is the relationship between Toxoplasma gondii and Isospora felis?
If a cat has recovered from T. gondii and is then subsequently infected with Isospora felis, the cat will re-excrete T. gondii oocysts
HOWEVER
If the cat was infected with I. felis first and then T. gondii, it will not re-excrete after recovery
What are two differentials for abortions in sheep
Sarcocystis
T. gondii (**)
Is T. gondii common in dogs?
No
C/S: respiratory, neuromuscular, GI
T/F if a cow herd is suffering from abortion, Toxoplasma gondii will be on your differential list
NO - rare and asymptomatic in cows
T/F - Toxoplasma gondii has few effects on pigs
True
Pigs are usually asymptomatic, but it may cause abortion
A bird is brought in with ocular and neurological lesions. Which protozoan do you suspect
Toxoplasma gondii
Toxoplasma gondii and which other protozoa are assciated with high mortality and severe protozoal encephalitis in marine mammals?
With Sarcocystis neurona
T/F - if you flush Toxoplasma oocysts down the drain they will be killed
False - and this is a way marine mammals can become infected :(
T/F - fecal float is gold standard diagnostic test for T. gondii in all species
False - only in cats (only cats shed oocysts!)
Give three ways of diagnosing Toxoplasma gondii
- Fecal float (*cats only)
- Serology (IgM –> active infection ; IgG –> previous exposure, immunity)
- IHC
A sheep farmer has ewes with Toxoplasma. You run a serology on 10 sheep. One comes back with high IgG - do you cull?
No, IgG indicates previous exposure and immunity
IgM would indicate an acitve infection
Whats this
Neosporum caninum
Which speices does Neosporum caninum infect?
Basically all animals
Who is the definitive host of Neospora caninum
Dogs (incl wild canids)
Transmission Neospora caninum
Fecal oral
Ingestion of cysts from infected animals
Does Neosporum caninum cross the placenta?
Yes - transplacental transmission of trachyzoites has been recorded in many animals
Is Neospora caninum zoonotic
Yes
A dog is presented with pneumonia and difficulty urinating. Which protozoan do you suspect?
Neospora caninum
Which protozoa causes abortions in dogs
Neospora caninum
Which protozoa causes ‘abortion storms’ in cattle?
Neospora caninum
How is Neospora caninum transmitted to puppies and calves? What are the c/s?
Vertical transmission!
C/S
- CNS signs
- Polyadiculoneuritis (hindlimb hyperextension)
T/F it’s probably a bad idea to breed a bitch with Neospora
TRUE - repeat transmission to future litters
Give 3 ways of diagnosis Neospora caninum
- Cysts or tachyzoites in CNS, heart, liver of fetuses
- PCR
- Serology
What’s this
Neospora caninum cyst
What causes blindness in foals (due to cysts forming in ocular muscles)
Neospora hughesi
What are your two differentials for Equine Protozoal Myeloencephalitis
- Neospora hughesi
- Sarcocystis neurona
A puppy comes in with hind limb paralysis. Which protozoan could cause this?
Neospora caninum
Can a horse get EPM in a country without oppossums?
No - opposums are DH
Can Toxoplasma gondii proliferate in faculative intermediate hosts?
Yes - asexual proliferation occurs
What does autoinfection mean? Which parasite does this occur in?
Sporozoites leave oocyst before entering feces - they can then re-enter the host’s system
Two types:
- Thin walled: re-infect host
Thick walled: exit host in feces (infectious to others)
Occurs in Cryptosporidium
