Deck 14 Flashcards
LC of Dictyocaulus (lung worm) in cows
- Adult worms in lungs:
Reside in the bronchi and bronchioles of the lungs.
Lay eggs, which hatch into L1 larvae in the lungs.
✅ 2. L1 larvae coughed up and swallowed:
L1 are coughed up, then swallowed and passed in feces.
✅ 3. Development in environment:
In feces or moist pasture:
L1 → L2 → L3 (infective stage)
L3 larvae migrate onto grass (often aided by fungi like Pilobolus)
✅ 4. Ingestion by cow:
Cattle eat L3 larvae while grazing.
✅ 5. Larval migration:
L3 penetrate intestinal mucosa → migrate via lymphatics and bloodstream → lungs
✅ 6. Maturation:
Arrive in lungs (after ~7 days), break into alveoli, migrate to bronchi, mature into adults.
Prepatent period: ~3–4 weeks
Key Points:
Infective stage: L3
Transmission: Oral ingestion of L3 from pasture
Location in host: Bronchi/bronchioles (lungs)
Causes: Verminous pneumonia, coughing, dyspnea (known as “husk” or “hoose”)
what eggs (2 eggs) can we find in flotation method on the pig feaces
- Ascaris suum
- Trichuris suis
ascaris suum - FH and location
FH - pig
loc - small intestine, EHP migrtion
what eggs can we find in sedimentation method/flotation method of ru
lc of syngamus trachea
✅ 1. Eggs laid in trachea:
Adult worms live in the trachea of birds.
Female lays bipolar-plugged eggs, which are coughed up, swallowed, and passed in feces.
✅ 2. Development in environment:
In soil or feces, eggs hatch → L1 → L2 → L3
L3 (infective stage) can remain in egg, free in environment, or inside a paratenic host
✅ 3. Infection of host:
Birds become infected by:
Ingesting infective L3 eggs
Eating paratenic hosts (e.g. earthworms, snails, slugs)
Ingesting free L3 in soil
✅ 4. Migration:
L3 penetrate intestinal wall → enter bloodstream → migrate to lungs and trachea
✅ 5. Maturation:
Worms mature in the trachea, form permanent male-female “Y-shaped” pairs
Cause “gape disease” – gasping for air, especially in young birds
🧬 Infective stage: L3 (in egg, free, or in paratenic host)
📍 Final location in host: Trachea
not microscopic methods for determination of oxyuris in horses
perianal swab/tape technique
lc of dipylidium caninum
✅ 1. Adult worms in intestines:
Live in the small intestine of dogs, cats, and sometimes humans.
Shed proglottids (tapeworm segments) in feces — they look like rice grains and are motile when fresh.
✅ 2. Eggs in environment:
Proglottids release egg packets containing oncospheres into the environment.
✅ 3. Ingestion by intermediate host:
Flea larvae (e.g., Ctenocephalides spp.) ingest the eggs.
Inside the flea → oncosphere → cysticercoid (infective larval stage)
✅ 4. Definitive host infected:
Dog or cat (or child) accidentally ingests infected flea during grooming or contact.
✅ 5. Development to adult:
Cysticercoid released in the intestine → matures into adult tapeworm in about 2–3 weeks.
📌 Key points:
Definitive host: Dogs, cats, humans (rare)
Intermediate host: Fleas (sometimes lice)
Infective stage: Cysticercoid (in flea)
Transmission: Ingestion of infected flea
Zoonotic: Yes, especially in young children
LC of taenia pisiforms (hosts and names of larval stages )
✅ 1. Adult worm:
Location: Small intestine of dogs or wild canids (e.g., foxes, coyotes)
Definitive host: 🐶 Dog
Proglottids (segments) containing eggs are shed in feces
✅ 2. Egg stage:
Eggs contain oncosphere (hexacanth embryo) and are passed into the environment via dog feces
✅ 3. Ingestion by intermediate host:
Intermediate host: 🐇 Rabbit or hare
Rabbit ingests eggs from contaminated grass or water
✅ 4. Larval migration & development:
Oncosphere hatches → penetrates intestinal wall → migrates to liver → then peritoneal cavity
Develops into the larval stage called:
🔴 Cysticercus pisiformis
(a fluid-filled bladder with an invaginated scolex)
✅ 5. Infection of definitive host:
Dog becomes infected by eating raw or undercooked rabbit viscera containing cysticerci
Cysticerci develop into adult tapeworms in the dog’s small intestine
70 micrometer size of an egg is
medium size
tapeworm world of ruminant spp
parapmhistomum
LC of echinococcus spp
✅ 1. Adult worm in definitive host:
Definitive host: Dogs, wild canids (foxes, wolves, etc.)
Adult tapeworm resides in the small intestine
Proglottids and eggs are passed in feces
✅ 2. Eggs in the environment:
Eggs contain oncosphere (hexacanth embryo)
Highly resistant in the environment
✅ 3. Ingestion by intermediate host:
Intermediate host: Sheep, goats, cattle, pigs, rodents, humans (accidental)
Host ingests eggs from contaminated food/water or direct contact
✅ 4. Larval development:
Oncosphere hatches → penetrates intestinal wall → migrates via bloodstream to liver, lungs, or other organs
Develops into hydatid cyst (E. granulosus) or alveolar cyst (E. multilocularis)
Cyst contains protoscolices (infective to definitive host)
✅ 5. Infection of definitive host:
Canid becomes infected by eating organs (usually liver/lungs) of infected intermediate host containing hydatid cysts
Protoscolices evaginate, attach to intestinal wall → mature into adult worms
which mm are predilection site for Nematoda detection (trichinella)
picture of toxocara leonine and Toxocara canis
picture of strongyles spp in sheep
oxyurida order - spp in horses
oxyuris equi - caecum + colon
round worms of pigs
taenia pisiformis IH
taenia saginata, site IH, FH
the stage inside arthropods in cyclophyllidae
metacestodes
