(23) The HOT Complex of Trichostrongyles

Question 1

Answer 1

Question 2

(Ostertagia Ostertagi)

1. aka?
2. host?
3. most important nematode in cattle worldwide

Answer 2

1. brown stomach worm (medium or western stomach worm)
2. cattle (abomasum)

(rarely in sheep, goats, and deer)

Question 3

(Ostertagia Circumcita)

1. found in what?
2. predominate parasite in western Us
3. how pathogenic vs. haemonchus contortus?

OSTERTAGIA SPP. PRACTICALLY IDENTICAL MORPHOLOGICALLY

Answer 3

1. abomasum of sheep and goats
2. less

Question 4

DIRECT LIFE CYCLE

Answer 4

Question 5

Answer 5

Question 6

1. how do they know when to resume development?

Answer 6

1. pregnancy/stress

Question 7

(Ostertagia spp)

1. Epidemiology:

what most susceptible?

they live inside what?

larvae can live under snowpack - but are suscpetible to dessication, direct sunlight, high temps

2. Path

L3 invade what?

grow and moult to L4 and then do what?

L5 adults emerge and cause damage - > do what? (phase II)

then mucosa becomes hyperplastic and non-fucntioning (phase II)

gradual loss of what?

Answer 7

1. young animals

fecal pat (good, moist condidtion - can get transported away by animals)

2. gastic gland (phase I)

damage cells which get replaced with undifferentiated

destory parietal cells (little HCl, no pepsinogen to pepsin, plasma proteins lost to gut due to cell junctions breaking down)

worms (phase III) –> grandual return to normal function

Question 8

(Ostertagia spp)

1. can be subclinical

Question 9

bottle jaw is symptom

primarily adult worms

Answer 9

Question 10

Answer 10

Question 11

(Osteotagia spp.)

1. treatment?
2. can cattle develop immunity?

Answer 11

1. most of new antihelmintics
2. yes - but more slowly than other ruminant parasites

Question 12

(Haemonchus contortus)

1. found in what?

(Haemonchus Placei)

2. found in what?
3. relative to contortus?

DIFFERENTIATING THE TWO IS DIFFICULT - use what species it is in

4. males have what?

females?

5. hatching of eggs driven by environment
6. what causes rise in spring?
7. path

primarily due to what?

cause what?

what are three syndromes in sheep?

8. Use what test for diagnosis?
9. treatment

Answer 12

1. abomasum of sheep

THe most important parasite of sheep

2. abomasum of cattle
3. less pathogenic/prevalent
4. promient bursa

barberpole effect with uterus wrapped around gut and vulval flap

6. immunologic relaxation
7. bloodsucking L4 and adults

anemia

hyperacute (rare - caused by lots), acute (high morbidity), chornic (low numbers ongoing) - basically the quicker it is the more worms there are the mre pathogenic it is

8. FAMACHA (fafa malan’s chart) - based on mucus membrane color
9. antihelmintics

Question 13

(Trichostongylus axei)

1. found where?

Answer 13

1. abomasum of ruminants, stomach of horses