Lecture 8: Trichostrongyles #1 Flashcards
(17 cards)
Male or Female trichostrongylus axei?
Also label the arrowed and bracketed features of this parasite.
Trure/False: The buccal cavity of a typical trichostrongyloid is bulbous.
False
List a genus for each of the four picutures that match the buccal cavity.
- ) Where can you find adult trichostrongyles?
- ) How about L3?
- ) How can an animal become infected?
- ) How long is the pre-patent period
- adults in stomach or small intestine
- develop in environment
- Infection by ingestion of L3
- can undergo hypobiosis
- 2 to 3 weeks
True/False: When Dr. Brewer gets all jacked up and receives a fecal sample and he’s anxiously wants to see which species of Trichostrongyle he gleefullly posses he can do so by looking at the eggs of trichostrongles in the feces.
False!
Anticipation is killing him as he sees all the strongyle eggs look the same. Dr. Jones, like an angel from above, points to the Baermann apparatus and that prompts a hearty chuckle from the Brewmeister.
He forgot that all strongyle eggs are classified “strongyle-type” eggs. The way to differentiate is to collect L3 by Baermann method!
A student in the back of the room watched Brewer/Jones ID situation unfold, and he is taken aback by the Baermann method. Dr. Brewer senses this discomfort and explains cooly to the student…
(Describe how Baermann method is performed and how L3 is collected)
*Dr. Brewer impersonation/jokes are encouraged in reenactment
- Collect feces in 4x4 gauze
- put into solution in Baermann method
- Larvae are motile so they’ll swim outside of gauze
- They aren’t good enough swimmers, so they sink to bottom of apparatus
- L3 collect in bottom and you take sample from bottom of apparatus to see which L3 larvae you have
- What’s the likely cause of ruminant parasitic gastroenteritis?
- Which parasite species predominate (BIG BAD GUYS) in the clinical signs of ruminant parasitic gastroenteritis for Cattle and Sheep/Goats?
- caused from mixed strongyle species
- trichostrongyles (primary agent)
- bunostomum, oesophagostomum, and Chabertia can also be involved
- Cattle: Osteragia ostertagi
- Sheep, goats: Haemonchus controtus
- What environmental conditions will kill strongyle larvae?
- What acronym can help you remember the most important ruminant nematodes?
- What does each letter refer to?
- very hot, very cold, or very dry conditions
- HOTT
- H- Haemonchus
- O- Ostertagia
- T- Telodorsagia
- T- Trichostrongylus axei
- You necropsy a sheep that has history of doing poor. The sheep is anemic, the muscles/viscera are pale, and the abosmasum is full of nematodes that resemble barber poles! Which species should you instantly put atop your differentials?
- Haemonchus contortus
- most important parasite of sheep, goats,a dn camelids
- Your buddy is eager to meet a Haemonchus contortus female. He asks you to help him find the alluring nematode. What characteristic should you be looking for to separate her from the rest?
- Female:
- white ovaries and red intestinal tract twist around each other
- barber pole
- large flap of cuticle over vulva
- white ovaries and red intestinal tract twist around each other
- Describe the buccal cavitity of Haemonchus contortus.
- Small buccal cavity with “lancet”
- lanclet used to lacerate the mucosa and obtain blood
- Describe the life cycle of Haemonchus spp.?
- What are the prepatent periods for H. contortus and H. placei?
- Direct life cycle: infection by ingestion of L3
- L3 ex-sheath in abomasum
- enter mucosa
- penetrate between gastric epithelial cells
- entry/exit into mucosa causes little damage
- Emerge from mucosa in abomasum as L4
- both L4,L5, and adults suck blood and move site to site in abomasum
- Prepatent periods:
- H. contrortus: 15 days
- H. placei: 25-28 days
- What are some factors in pathogenicity for Haemonchus?
- True/False: A clincal sign for H. contortus would be diarrhea.
- Factors:
- Short pre-patent period
- females are prolific egg layers
- voracious blood feeders
- False
- Anemia!!
- both L4, L5, and adults are voracious blood suckers in abomasum
- Diarrhea is not generally a feature, unless mixed with othe strongyles
- Anemia!!
- When can Peracute/Hyperacute hemonchosis occur?
- What would you find when you necropsy an animal with Peracute hemonchosis?
- Occurs in massive infection in a highly susceptible animal
- bleeds to death in
- Find:
- 1000s of worms
- mainly L4
- Severe hemorrhagic gastritis
- Pale organs
- melena in feces
- black, digested blood
- 1000s of worms
- You see a fluid accumulating beneath a ewe’s mandible. What disease rises atop your differential list?
- What’s the pathogenesis for this lesion on the ewe?
- Acute hemonchosis
- You’re seeing “bottle jaw” which is from
- Pathogenesis:
- Blood loss due to parasites suck blood and blood is lost via feces
- Hypoproteinemia
- loss of blood proteins from Haemonchus and feces
- results in decrease of oncotic pressure
- See edema in submandibular, facial, and ventral abdomen
What’s the difference between acute hemonchosis versus chronic hemonchosis?
- Acute hemonchosis has much more eggs found in the feces
- More parasites in acute hemonchosis than chronic syndrome
- Chronic hemonchosis doesn’t have obvious signs of anemia or edema
You do a necropsy of a ewe you expect of chronic hemonchosis, what should you find?
- emaciated carcass
- poor fleece quality
- low number of worms
- increased red marrow in long bones
- ewe has partially compensated for blood loss
