Review Questions Exam # 2 Flashcards
Adults of which nematode species can be found in the heart of dogs/cats?
Dirofilaria immitis
What are the definitive hosts, and Intermediate hosts for heartworm (domes:c and
wildlife)?
o Definitive host: Dogs, Cats ( less favorable), other: wild canids
o Intermediate hosts: Mosquito
What is the infective stage of heartworm for dogs?
o L3- Infective to dogs.
What heartworm stage is found in the blood?
o Microfilaria - L1
How do mosquitos get infected?
o Mosquito acquires L1 during blood meal and the microfilaria will develop to L3 in mosquito ( 15-17 days and temp dependent)
How do dogs get infected?
o Mosquito feeds and on dog and L3 migrates into SQ tssues where it molts to L4
What pathological changes do heartworm cause in the heart and arteries?
o Endarteritis, thickening of vessels, loss of vessel elasticity, increased pressure, right heart enlargement and CHF. Can cause caval syndrome (worm blocking caudal vena cava/ tricuspid. Needs immediate surgical intervention.
What diagnostic parasitological tests are recommended by the American Heartworm
Society?
o Elisa/ SNAP, Lateral flow immunochromatography
What is the target of the commercial antigen tests available?
o Detect antigen of mature female heart worm
When should you start testing for heartworm and why?
o Test after 6 months, clinical disease not seen for 5-6 months so negative results are inconclusive until after that point. Must test when worms are adults.
What other species of microfilaria can be present in the blood of dogs/cats?
o Acanthocholonema reconditum
What is the advantage of knott’s test over direct smear? What do the test’s detect?
o Knotts Test is more sensitive, allows species ID and quantitative if needed.
What stages of heartworm do heartworm preventatives target?
o Preventatives Kill L3 and L4
How is feline heartworm disease different to canine heartworm disease?
o Cats have lower worm-load, typically 1-3 worms, but up to 6.
o Normally there is a male only infection (no microfilaria is produced) thus microfilaria test will be negative and so will snap test.
Why would a dog who is positive on antigen test be negative on knott’s test and vice versa?
o (+) antigen, (-) negative knotts : MF below detection threshold ( happens in cats)
No circulatory MF yet. Female only infection. Residual antigen ( dogs may have
residual antigen 6 months post treatment). Cross reaction (rare) with other
antigens.
o (+) Knotts, (-)antigen: Test error possible if there is negative snap but positive
Knotts. Antibody antigen complexes can be created so the antigen will not be free to be detected. Send to lab for heat treatment ( serum, to retest and unbind complexes)
List the species of parasites found in the lungs of dogs/cats.
o Angiostrongylus vasorum- French HW
o Angiostrongylus cantonensis - rat lungworm,
o Aelurostrongylus abstrusus - Feline Lungworm
o Filaroides spp. (Filaroides hirthi, Oselerus/Filaroides osleri)- Canine lung worm
o Crenosoma vulpis - fox lungworm
o Capillaria (Eucoleus) spp, - Tracheal worm
What is French heartworm? Is the lifecycle direct or indirect? What is the intermediate host?
o Angiostrongylus vasorum- French HW
o Indirect lifecycle
o Intermediate host: gastropods
What is the shed stage of lungworms, and how do you diagnose them? (fecal method)?
o Shed Stage: L1
o Fecal method: Baermann or serology. Fecal float can also be used but less reliable.
Name the feline lungworm – what is the key pathology on the lungs?
o Aelurostrongylus abstrusus - Feline Lungworm
o Verminous pneumonia in heavy infections
(Heavy burdens can be fatal) Grey nodules scattered on surface of lungs which release larva + milky fluid if incised.
Common name of crenosoma vulpis?
o Fox lungworm or bronchial worm
What is unique about Filaroides spp. (lifecycle), transmission and disease?
o Has direct lifecycle. L1 immediately infective
o Transmission high in kennels, auto infection, Maternal grooming, Ingestion L1
What kind of lesions/pathology do Filaroides osleri cause?
o Characteristic tracheal nodules at bifurcation. Nodules contain adult
nematodes ( from 3-11 mm)
o Pathogonomic cough/ retch triggered by exercise, cold ect. Nodules can obstruct airway/ cyanosis and collapse in pups.
o Hyperinfection due to autoinfection could be fatal.
Which lungworms have larvae with a dorsal spine?
o Angiostrongylus spp o Aleurostongylus
What is the other name for Eucoleus spp.?
o Capillaria or tracheal worm
What is the shed/diagnostic stage of Eucoleus? What is the differential diagnosis?
o Shed: L1 (egg stage)
o Diagnostic Stage: L1 (eggs)
o DDX: Dry cough, dyspnea, DDx with allergic rhinitis for correct treatment.
How can we prevent lungworm infection in dogs? Filaroides? Other?
o Lungworm: Control access to intermediate hosts, proper disposal of feces.
o Filaroides: isolate sick dogs and treat, but treat all animal s in home to break horizontal transmission
Two common species of eyeworms?
o Thelazia Spp. (T callipeda, T californiensis)
o Onchocerca lupi
Intermediate hosts of eyeworms? Both species
o Intermediate hosts/ vectors are Fruitflies, Housefly for Thelazia, and blackfly for
onchocerca lupi
Key lesion associated with eyeworm infection?
o Nodules, red eye, watering, ocular lesions, ocular edema, photophobia, conjunctivitis.
Which worm is found in the kidney of dogs/cats? Common and scientific names, natural hosts?
o Dioctophyme renale ( giant kidney worm)
Natural hosts are minks
How do dogs and humans get giant kidney worms?
o Transmission: Dogs + humans get infected by ingestion of Paratenic hosts (fish + frogs) containing L3, Intermediate hosts containing L3
How do you diagnose a Giant kidney worm? Method only.
- Urinalysis (UA)
oHigh-level morphology of eggs of kidney worm! – Lemon-shaped, thick-walled and folded eggshell!
Where are Dracunculus and larva of Pelodera found?
SQ Tissue
What is the natural host of Dracunculus? Intermediate host?
o Hosts: Dogs and cats that hunt frogs, prevalence in raccoons can exceed 50%.
Potentially zoonotic but no human cases right now.
o Intermediate Host: Crustaceans (copepods)
What stage of Pelodera is infective?
o L3 is infective, but no systemic migration.
What is the predilection site for Tanenia spp. adults in dogs and cats?
• Adults of several of these species can be found in intestines
What kind of larvae is inside the eggs shed by Taenia spp?
- Shed tapeworm eggs
- Proglottids
- Immediately infective
- Hexacanth Larva
Do intermediate hosts of Taenia shed eggs in the feces? What is the stage present in the Intermediate hosts?
◦ Intermediate hosts do not shed eggs in the feces. They will develop larval cysts which upon ingestion will infect the definitive hosts. In the Intermediate host, the will consume eggs which develop into larva (metacestodes) while in vertebrate host.
How do dogs get Taenia infection?
◦ Dogs + Cats infected when ingesting larval cysts while preying/ scavenging infected vertebrates
Fecal floatation with Zinc sulfate can produce false-negative results for Taenia diagnosis why?
The Specific gravity of zinc sulfate is 1.18 and Taenia eggs are heavy, and must have a fecal float done with centrifugation and a float solution with a specific gravity of > 1.3
What is the baby tapeworm inside the tapeworm cyst?
◦ Protoscolex- just the head of a baby tapeworm
How to control dogs/cats from getting adult Taenia spp, and from contaminating the environment?
Prevention of predation and scavenging activity by keeping cats indoors and dogs confined to a leash or in a fenced yard
Cook or freeze offal and meat before feeding to the dogs
Special consideration for dogs on sheep farms – regular deworming (twice a year)
What species of Taenia have humans as definitive hosts? Which animal species serve as their intermediate hosts?
- T. saginata – Beef tapeworm
- Called as beef tapeworm because larval stages are in Cattle!
- T. solium – Pork tapeworm – Food borne parasitic zoonsis!
- Serious foodborne zoonosis
- Called as pork tapeworm because larval stages are in the PIGS!
*Neurocysticercosis
What are the two echinococcus species that can infect canids?
- E. granulosus/ E. Canidensis
- E. Multilocularis
Which echinococcus species have a pastoral cycle?
E. granulosus
Which echinococcus species uses rodents has IH?
E. multilocularis
Type of cyst formed by Echinococcus granulosus in ruminants?
Hydatid cyst
Which species of echinococcus can cause canine alveolar echinococcosis?
E. multilocularis
How to diagnose echinococcosis in dogs and cats?
– Fecal testing
- Fecal sedimentation, Fecal floatation (solution with high sp. Gravity). - Taeniid type egg – Morphologically indistinguishable to Ta e n i a spp. eggs
- Copro PCR to differentiate between Ta e n i a and Echinococcus
- Diagnosis of canine alveolar echinococcosis (Dog IH)
- Clinical signs – liver mass in medical imaging
- DDx with neoplasia, granuloma and other cysts
- Immunohistochemistry, PCR
- Abdominocentensis, Aspirated cyst contents, biopsy
Why the adults of echinococcosis should be treated?
Primarily public health considerations. Have owner talk to health provider about potential exposure.
Which tapeworm do fleas carry?
Dipylidium caninum
What is unique about the egg morphology of flea tapeworm? Diagnostic method?
Fecal flotation wont work for D. caninum – Eggs in egg packets (very heavy). Use Fecal sedimentation
Morphology: Each packet contains up to 30 eggs. Each egg contains a
hexacanth larvae. HEAVY • Does not float well
What is the infective stage of flea tapeworm?
◦ Within fleas ( Fleas must be ingested) Cysticercoid
What are the clinical signs associated with Dipylidium caninum infection?
◦ rarely cause clinical signs in canines.
◦ Most common is itching from proglottids moving in the anal area/ rubbing of caudal area due to discomfort. Gi disturbances in very rare cases
How may humans get infected with Dipylidium caninum?
- Children can get D. caninum if they ingest tapeworm (within flea) Mild GI signs
Segments/Proglottids of which tapeworm resembles cucumber seeds?
◦ Dipylidium caninum
Which is “double pored dog tapeworm”?
◦ Dipylidium caninum
How can dogs and people get fish tapeworm?
Transmitted from eating fish containing infective larvae – more prevalent in costal areas or areas near lakes/water bodies
Raw fish is the issue. Cooked/ deeply frozen fish is fine.
How can dogs and people get fish tapeworm?
◦ Transmitted from eating fish containing infective larvae – more prevalent in costal areas or areas near lakes/water bodies. Raw fish is the issue
First and 2nd intermediate hosts of fish tapeworm?
◦ IH1- Crustacean (Procercoids)
◦ IH2- Fish ( Plerocercoids)
What is the infective stage of Diphyllobothrium?
◦ Plericercoids (within 2nd intermediate host usually other fish)
Which tapeworm can cause Proliferative sparganosis in dogs?
◦ Spirometra
What is the infective stage of Mesocestoides spp. called?
• Infective larvae in 2nd IH called tetrathyridium (metacestode)
List the surface and burrowing mites of dogs and cats (scientific and common names).
Surface:
• Cheyletiella spp. – Rabbit Fur Mite / Walking dandruff
• Otodectes sp. – Ear Mite
• Eutrombicula spp. – Harvest mite
• (Pneumonyssoides caninum – Nasal mite)
Burrowing mites:
• Sarcoptes scabei – Canine Scabies Mite
• Notoedres sp. – Feline Scabies Mite
• Demodex spp. – Demodectic Mange Mite
How can you differentiate surface mite from burrowing mite?
Surface Mites:
- Dorso-ventrally, flattened Long legs
Burrowing Mites:
• Short stumpy legs, Deep in the skin, Requires deep skin scrape
Key pathogenesis of Cheyletiella spp? ear mites?
Cheyletiella
Direct contact – most important route of infestation
- Spread between dogs, via grooming instruments like combs and brushes.
- Can ride on larger parasites like lice, fleas
- Cause Clinical cheyletiollosis mainly in puppies
- Copius dandruff on puppy’s back
- Generalized chyletiellosis is rare
- Pruritis (severe itching) is common
- Zoonosis: itchy red papular rash on arms and trunk
Otodectes cynotis
• Mild to severe
- Copious ground coffee like discharge
- Head shaking, behavioral disturbances due to ear infection
What is the infective stage of harvest mite?
Larval stage
Where do Sarcoptes mite live?
- Highly contagious, live in the tunnels dug in the epidermis
Key lesions associated with Sarcoptes mange?
- Hair loss
- Crustose and scaly lesions in the pinnal margin (Ears, elbows, ventrum, tarsal)
- Hyperkeratosis
- Itch worst in warm conditions and in night
- Early signs- Erythematous and papulomatous dermatitis around ear pinna
Which mite is considered as Sarcoptes of cats? Do adults of this mite survive off host?
Notoedres sp
Adults do not survive in the environment
Where does Demodex mite live? Are these mites contagious? Zoonotic?
- Live in hair follicles and sebaceous glands
Not zoonotic, not contagious
No environmental survival
What are the differences between localized and generalized demodicosis?
Localized Demdecosis: young animals (3-18 months), Mostly short hair dogs, around mouth, nose, eyes, forelegs, base of tails, rarely ear canals. Causes focal alopecia (mites loosen hair in follicles), non pruritic and typically self resolving
General Demodecosis: Older animals (>1.5 years) Severe form- poor prognosis, often due to underlying immune deficiencey or concurrent diseases. Difficult to treat. Deep pyoderma, crust covered in dermal lesions.
How can you diagnose mites?
◦ Skinscrape can determine scarcoptes vs. demodex (deep or superficial)
◦ Tissue test ( with KOH)
◦ Visual inspection
◦ Mites slide
Identify the mites that are contagious, zoonotic and that have environmental survival
Mites that are contagious/ environmental survival/ zoonotic.
- Cheyletiella, Otodectes, Eutrombicula, Sarcoptes, Notoedres ( cannot survive in environment) D. gati (can be contagious, no environmental survival)
Which tick species are American dog tick, Rocky Mountain wood tick, deer tick and brown dog tick? Are they one host or three-host ticks?
American Dog Tick: Dermacentor variabilis ( 3 host)
Rocky Mountain Wood Tick: Dermacentor andersoni (3 host)
Deer Tick: (3 host tick)
Ixodes scapularis – Eastern black-legged tick
Ixodes pacificus – Western black-legged tick
Brown Dog Tick: Ripicephalus sanguineus (3 host, but can remain on same dog)
Which tick species is more common indoors/ in kennels?
◦ Brown Dog Tick
Which Tick species transmit Lyme disease?
Deer Tick
Describe the key pathology of Lyme disease in dogs.
◦ Shifting lameness (arthritis), anorexia and low-grade fever, Nephritis most common clinical sign, Rarely neurological, cardiac, and ocular issues.
◦ Can be detected after 6-8 weeks. Signs can begin 2-5 months through exposure.
Can infected dogs transmit Lyme disease to humans? Why?
◦ No they cannot, tick vectors are needed.
Name the dog and cat fleas.
Ctenocephalides felis (CATS, DOGS, \>50 spp) Ctenocephalides canis (DOGS, wild canids)
How can you differentiate dog flea from cat flea? Head morphology?
Ctenocephalides felis (CATS, DOGS, \>50 spp) - More common than dog flea. Both in dogs and cats
- Transmits Flea-borne (murine) typhus and cat scratch disease (CSD) in humans
- Head Morphology: Head is flat compared to canis. First genal spine almost as long as the 2nd.
Ctenocephalides canis (DOGS, wild canids)
- Less common than cat flea.
- Intermediate host for Dipylidium caninum, Acanthocheilonema reconditum
- Head Morphology: Head is rounder then felis. First genal comb is shorter than second
List the common fluke species that can infect dogs and cats and their predilection sites.
- Paragonimus kellikotti- Lung fluke
- Alaria spp.- Intestinal fluke, immature flukes in lungs
- Nanophyetus salmincola- causes salmon posioning, not infection ( microbe infection)
- Metorchis spp.- Liver Fluke
- Heterobilharzia american: Blood fluke/ liver fluke
What are the first and 2nd intermediate hosts of Alaria?
◦ Mollusk 1st IH, Frogs/tadpole 2nd IH
What is unusual about the diagnosis of Alaria?
Eggs float well in fecal flotation of sugar solution. This is unusual for trematode eggs.
How can humans get alaria infection?
From the ingestion of undercooked frogs legs.
Which fluke species is associated with salmon poisoning in dogs and humans? How do we/dogs get the infection?
Nanophyetus salmincola- Eating Raw fish
What is the causative agent of salmon poisoning?
Neorickettsia helminthoeca
What is the liver fluke of dogs?
Metorchis spp.
heterobilharzia americana
What is the lung fluke of Dogs?
Paragonimus kellicotti
How do dogs get liver fluke infections?
◦ Eating Raw fish
How do dogs get lung fluke? Intermediate hosts?
◦ Ingesting Raw Crayfish.
◦ IH1: Snails, IH2- Crayfish
How can we diagnose lung fluke? High-level egg morphology?
- Sedimentation of broncho-alveolar lavage (BAL) or fecal samples
- Eggs (large, operculated) in feces or in Sputum. The worm cysts can be visible in radiography The yellow-brown, operculate eggs can be identified by the characteristic thickened multisegmented cystic structures
ridge in the shell wall along the line of the operculum (arrow).
Which schistosome fluke can infect dogs? What is unique about this fluke?
◦ Heterobilharzia americana
◦ Dioecious (Male and female separate) – Exception within trematodes!
The infective stage of Heterobilharzia, mode of transmission.
◦ Cercaria (infective stage). Penetration of skin is method of transmission
List the most common flagellate protozoa of dogs and cats in North America
◦ Mucosoflagellates: Giardia, Tritrichomonas
◦ Hemoflagellates: Trypansoma, Leishmania
What is the key symptoms associated with giardiasis?
- Diarrhea, Weight loss, vomiting, dehydration, poor coat appearance
Can dogs pass giardiasis to humans? Can humans give giardia to pets?
◦ Pets can have host-specific genotypes as well as zoonotic genotypes of Giardia. People only get (and give!) zoonotic genotypes of Giardia. So it depends.
What are the key risk factors for giardiasis?
◦ Young animals (< 1 year)
◦ Suboptimal environment
◦ Stressed/immunocompromised
What is the best way to detect trophozoites of Giardia in a fecal sample?What is the best way to detect cysts of Giardia in a fecal sample?
◦ Diagnostic test options: Direct, fresh fecal smear (saline)(trophozoites, cysts), Zinc sulfate flotation (cysts)
◦ Lugols iodine may be added to make internal structures more prominent.
Which protozoa causes chronic large bowel diarrhea in cats?
Tritrichomonas foetus
What is the infective stage of Tritrichomonas foetus?
Shed and infective stage – Trophozoites
What is the disease caused by Trypanosoma cruzi in the US?
◦ American trypanosomiasis (Chagas disease)
What are the vectors for T. cruzi?
◦ Triatomid (Kissing bugs)
How do dogs get infected with T. cruzi? Modes of transmission?
◦ The dog becomes infected by: Eating the feces of the infected bug. Eating infected bug. Wound contamination by the bug. Blood transfusion
◦ Bug will transmit it via taking blood meal from dog and ingesting trypomastigote
Where will you find the Trypanosoma stage in the blood smear ? What is the name of?
◦ Blood smear (Giemsa stained) visualize the trypomastigote form Insensitive due to low numbers in the blood
Name the common chewing and sucking lice of dogs and cats.
Chewing Lice ( Mallophaga/Ischonocera)
◦ Trichodectes canis - Dogs
◦ Felicola subrostratus - Cats
Sucking Louse (Anoplura)
◦ Linognathus setosus - Dogs
How can you identify Chewing vs Sucking lice?
◦ Sucking lice: Narrow head adapted for sucking; legs specialized for holding onto hairs. Note shorter length of first pair of legs. Piercing mouthparts
◦ Chewing Lice: head is blunted, convex and wider than the thorax. Large mandibles.
Outline the lifecycle of lice, how is it different from flea lifecycle?
◦ Lifecycle: Adults feed on host. Lay eggs on host (eggs take 1-2 weeks to become nymphs) Nymphs then take 2-3 weeks to become adults. Fleas lifecycle is mainly off the host.
How can you manage lice infestation?
- Flea/ Tick control methods: Selamectin, isoxazolines
- All dogs in direct contact should be treated
- Topical insecticides (pyrethroids, pyrethrins, imidacloprid) as shampoo,
dips, spot-ons
UNSAFE for cats
- May have to re-treat in 1-2 weeks (nits resistant)
- Systemic treatments may work better on sucking lice than chewing lice
- Environmental hygiene
Which fly species can cause bots/grubs in dogs and cats?
Caused by rodent or rabbit bot flies – Cuterebra spp. , Dermatobia hominis
Outline the lifecycle of bot fly in dogs/cats
◦ Female deposits opening near animal nests -> Dogs/ Cats become infected as they walk by -> Larva penetrate and migrate to various SQ locations where they develop -> After 1 month larva exit skin, fall into soil and pupate (dependent on external factors) ** adults will emerge in spring**
Key pathology of grubs in dogs/cats
◦ A well-demarcated, soft, fistulous swelling in the late summer or early fall – key sign
◦ Aberrant migrations to heard, brain, nasal passages, pharynx, eyelids
◦ Secondary infection: Purulent exudate (ddx – foreign body abscess
Is cryptosporidium host specific? Which species has broader host range?
Host-specific - except Cryptosporidium parvum
C. parvum – people, calves, rarely dogs
Can people give the crypto infection to pets? Or vice versa? Which is more common?
People can give Cryptosporidium to pets, but rarely vice versa
What are possible transmission routes for cryptosporidium?
Fecal oral
Respiratory route (possible)
Autoinfection - can cause hyperinfection in immunocompromized patients and cause severe pathology.
What makes cryptosporidium more transmissible/infective?
◦ It is immediately infective and can survive in the environment for a long time.
What is unique in the pathogenicity of Cryptosporidium?What stage?
- immediately infective within the intestine, hyperinfection in immunocompromised animals with severe pathology . Sporulated oocysts are immediately infective, and is is zoonotic.
How can you control Tryanosomiasis?
◦ Control by vector control. Don’t let dogs eat reservoirs, screen blood donors, and breeding control to protect against vertical transmission.
What are the vectors for Leishmania?
- Spread by sandflies
Which species causes visceral leishmaniasis in dogs in North America?
L. infantum - Causes Visceral Leishmaniasis in dogs and humans
What are the insect and mammalian forms of Leishmania?
◦ In the insect : Promastigote (extracellular in the gut)
◦ In the mammal : Amastigote (intracellular - in the macrophages)
What are the modes of transmission of leishmania to dogs?
- Transmission through bite of sandfly (two genera – Lutzomyia, Phlebotomus)
- Vertically from dam to pup
- Dog – dog transmission (fighting, blood transfusion)
What is the typical lesions associated with Leishmaniasis in dogs?
◦ Skin lesions ( Dermatitis, deep pyogranulomatous dermatitis, ulcerative erythemotous lesions, onychogryphosis.) (80-90% of the cases), ocular abnormalities or epistaxis
◦ Other: Corneal opacity, conjunctivitis, Generalized alopecia, Lymphadenomegaly, Weight loss, exercise intolerance lethargy
Why is the risk of contracting leishmaniasis in the US low? ***
- We are NOT endemic for L. infantum, but we do support L. mexicana transmission cycle (sandflies and reservoirs in southern US)
What are the risk factors for canine leishmaniasis in the US?
- Dogs that were imported from or travel history to Europe, Mediterranean, Middle East (usually L. infantum endemic areas)
- US Foxhounds with L. infantum transmitted vertically
- Dogs (and cats) from TX can become infected with L. mexicana (causes skin lesions)
List the common apicomplexans that can infect dogs and cats in the US.
Intestinal Ampicomplexa:
◦ Cystoisospora spp.
◦ Cryptosporidium parvum
Systemic:
◦ Sarcocystics spp.
◦ Neospora caninum
◦ Toxoplasma gondii
Blood Apicomplexa:
◦ Babesia spp.
◦ Hepatozoon canis
What are intestinal coccidia of dogs and cats?
◦ Cystoisospora spp.
◦ Cryptosporidium parvum
What is the key pathogenesis of Cystoisospora spp? What are the key risk factors?
◦ Direct destruction of enterocytes (small intestine)
◦ Mild to moderate diarrhea (loose, mucoid), rarely bloody
◦ Common in nursing, recently weaned pets
◦ Stress – shipping stress, nutritional stress, kennel stress
◦ Clinical disease depend upon the dose of sporulated oocysts!
◦ Small-bowel diarrhea in kittens
◦ Key risk factors: Age, History, immunocompromised, stress
How can you control/manage Cystoisospora infection in dogs?
◦ Treat whole litter – Early treatment minimizes the damage
◦ Give supportive therapy for symptoms
◦ Once infected, have immunity against that species
◦ Sanitation, prevent access to paratenic hosts, Good nutrition, keep stress low
Why is control of cryptosporidium more challenging?
◦ Sporulated oocysts are resistant, can survive (year) in moist, protected environments
◦ Susceptible to freezing or extremely high temperatures; ammonia solution
What are the main definitive and intermediate hosts for Neospora, toxoplasma, and
Sarcocystis?
◦ Neospora: DH: Canids (dogs, coyotes) IH: Vertebrate ( especially herbivores
◦ Toxoplasma: DH: Felids , IH: Dogs, Facultative Hosts: Cats, dogs, people. Wode range of vertebrates
◦ Sarcocystis: DH: Canids and Felids, IH: Cattle, Sheep, Horse, Pigs.
Is Neospora caninum zoonotic?
◦ Non zoonotic
Modes of transmission of systemic Apicomplexa to definitive and intermediate hosts.
Definitive Hosts: Eating Tissues of infected animals ( bradyzoites)
Intermediate hosts: Ingestion of Oocyst from envrionment
Key pathogenicity of Neospora caninum in dogs?
- Often asymptomatic. Not all pups infected with tissue cysts, and
not all infected show signs. Can infect subsequent litters. Most severe in congenitally infected puppies: neurological and skeletal muscle
(progressive hindlimb paralysis, dysphagia) - Older dogs: encephalitis, myopathy, A hind limb paresis with rigid hyperexpension of hind limbs ulcerative dermatitis
Is fecal flotation reliable for Neospora diagnosis? Why?
◦ Fecal flotation is not very reliable (oocysts shed only for a few days – week)
How to prevent the infection of Neospora, toxoplasma, and Sarcocystis in dogs and intermediate hosts?
Neospora: Prevent contamination of livestock feed with canine feces. Do not allow dogs to ingest bovine placental tissues, fetal membranes, or other raw meats. Do not breed seropositive female dogs.
Toxoplasma: Clean litter boxes daily (before sporulation). Keep cats indoors (out of gardens, away from prey). Feed only commercial, cooked or frozen* diets. Goal of treatment is primarily to reduce transmission (congenital or oocyst shedding.
Sarcocystis: Sanitation, Keep animals inside/ away from IH, beware of positive Queens/ bitches. No raw meat.
What are tachyzoites and bradyzoites?
Tachyzoite = fast growing zoite & Bradyzoite = slow growing zoite
How is the oocyst of Sarcocystis different from the oocyst of other Apicomplexa?
- Sporocysts leave the host in the feces and are immediately infective to intermediate host
- Oval sporocyst containing 4 sporozoites. Immediately infective
For which apicomplexa, the oocysts are immediately infective?
Intestinal apicomplexa: Cryptosporidium parvum
Systemic Apicomplexas: Sarcocystics spp.
Blood Apicomplexa: N/A
Where can you find Babesia and Hepatozoon in the blood smear?
Babesia: Identification of piroplasms in erythrocytes on stained blood smears
Hepatozoon: Parasitic gamonts in neutrophilic granulocytes
Vectors for Babesia? Are ticks IH or DH?
Vectors are dogs
Two hosts – Ticks DH, Dogs IH (B. canis)
Routes of transmission of Babesia and Hepatozoon?
Babesia: Tick bites. Iatrogenic transmission through blood transmission or blood-
contaminated fomites. Fighting dogs high risk
Hepatozoon spp: There is oral transmission (ingestion of the tick) in dogs, as well as trans placental transmission
EXTRA INFO: What are the lifecycles of Babesia and Hepatazoon?
Babesia: Merozoites in dogs blood. Ticks igest merozoites with blood. Sexual reproduction occurs in ticks and sporpgony are in ticks saliva glands. Sporozoites are released into saliva, where they are passed into dog while feeding on blood. Sporozoites then attach to dogs red blood cells and circulate within body
Hepatozoon spp: Sporozoites penetrate the intestinal wall to blood
(Monocytes and macrophages ) to spleen, liver, lymph nodes, bone marrow, lungs, pancreas and skeletal t/s. Ticks infected while sucking blood
of the infected animal. There is oral transmission (ingestion of the tick) in dogs, as well as trans placental transmission
Key pathology of Babesiosis and Hepatozoonosis in dogs.
Babesia: Canine babesiosis – Moderate to severe hemolytic anemia. Thrombocytopenia, hypoalbuminemia and hyperglobulinemia. Clinical disease (Uncommon)
- Immunocompromised dogs: Fever, anorexia, depression, splenomegaly and a bounding pulse
- Clinical sings can appear well after tick detachment (infection to clinical signs 10 – 28 days)
Hepatozoon: Usually subclinical. Can cause fever, poor appetite, enlarged lymph nodes.
Exception H. americanum – severe disease- Fever, myositis, muscle atrophy, purulent eye discharge, anemia, death!
- Large zoite containing macrophages (cysts) between muscle fibers. Cysts rupture and acute inflammatory response occurs followed by pyogranulomatous inflammation and clinical illness. Prolonged infection: progressive weight loss and death within 12 months after infection.
How to control the blood apicomplexans?
Blood Apicomplexans : Tick control – acaricidal treatment
- Tick prevention
- Removal of tick promptly in cases of Babesia.
- keep pets away from ticks to prevent ingestion in dogs.
In which Apicomplexa, the transmission can occur between intermediate hosts? What is the infective stage?
◦ Toxoplasma gondii
◦ Tachyzoites - Acute infection
What is the major risk factor for the transmission of T. foetus in cats?
◦ High density/ cattery and poor hygine
Why is the risk of contracting leishmaniasis in the US low?
◦ We are NOT endemic for L. infantum, but we do support L. mexicana transmission cycle (sandflies and reservoirs in southern US)
What is the infective stage of giardia? What is the reproductive stage?
Reproductive state: Trophozoites (inside the definative host)
Cysts -> infective in the environment, more numerous)
binary fission
