Trichostrongyles 2 Flashcards
Name this condition and a parasite that can cause it.
“Bottle Jaw”
Submandibular edema. Commonly seen in cases of Haemonchus contortus infection.
What system can you use to gauge the severity of anemia in goats?
FAMACHA
What is premunition?
A state of resistance to chronic infection which is established when an acute infection becomes chronic and lasts as long as the infecting organisms stay in the body.
What are the two principles of selective therapy?
(Brewer keeps harping on this, so it’s probably totes important)
- Minimize the number of eggs in the environment and guard against clinical signs.
- Use drugs in such a way that we slow the spread of resistance.
Selective therapy relies on which two observations?
- Parasites are unevenly distributed (overdispersed). So, a small proportion of individuals shed the majority of the parasite eggs.
- Strongyle egg shedding is consistent over time. High egg shedders will remain high egg shedders.
You detect Haemonchus contortus in your goat population. You should probably just deworm all the goats, right?
If you do that, I’m going to have to beat you over the head with a FAMACHA chart.
Remember, we want to only treat the goats showing the most severe signs of anemia. By selectively treating, we keep some susceptibility genes in the population.
This goat is shedding eggs. Should you treat this goat?
He’s fine. Let him keep eating cans or whatever goats do.
This goat is shedding eggs. Should you treat this goat?
I’m surprised he’s still standing. TREAT IMMEDIATELY.
This goat’s probably fine, and I don’t want to spread anthelmintic resistance. Am I right?
Bro, do you even FAMACHA?
You should treat goats that score a 4 or 5 on this chart.
What test is this?
DrenchRite Assay
This is a larval development assay. It is used to test larval sensitivity to anthelmintics.
H. contortus is most resistant to which class of anthelmintics?
Benzimidazoles
By what percentage should an anthelmintic reduce FEC in order to be considered effective?
95%
True or False:
Self cure (purging of worms once the animal reaches a certain level of immune development) is consistent in Haemonchus infections, just like with ascarids.
FALSE
Whereas most animals tend to self-cure ascarids by 6 months, the phenomenon is not as consistent in Haemonchus infections.
This chart is trying to tell you something. Decode the crytpic symbols and tell me what it means.
Reduction in FEC against Haemonchus is inconsistent with Albendazole and Ivermectin (suggests resistance). Levamisole and moxidectin have better clearing rates.
If you’re going to cut your cocaine with an anthelmintic, which anthelmintic should you use?
Levamisole!
In which host do you typically find Ostertagia ostertagi?
Cattle
In which hosts do you typically find Telodorsagia?
Sheep
Goats
Camelids
Name the major species of stomach trichostrongyles.
- Haemonchus*
- Ostertagia*
- Telodorsagia*
- Trichostrongylus*
(Remember HOTT. As in: being able to recite the stomach worms is super HOTT and sexy)
Identify the species.
Ostertagia ostertagi
Note the annular striations near the mouth that give way to longitudinal striations along the body. Isn’t that pretty? Now, unless you carry a SEM in your back pocket for diagnostics, I suggest you not waste too much time on these features.
What color are adult Ostertagia inside the host?
Brown
What is the most important parasitic nematode of cattle?
Ostertagia ostertagi
Where do adult Ostertagia ostertagi live?
Abomasal lumen
What is the major difference between L3 migration in Ostertagia and Haemonchus?
- Haemonchus* enters BETWEEN the cells of the gastric glands.
- Ostertagia* enters INTO the gastric glands.
What is the prepatent period of Ostertagia?
3 weeks
