Cattle Parasites

Question 1

How long does it take Trichostrongylus spp. to develop once eggs are passed in the manure?

Answer 1

(5-7 days to get to L3, if its cooler it will take longer)

Question 2

Once L3 Trichostrongyles become adults in their hosts, how long does it take them to start laying eggs?

Answer 2

(3 weeks)

Question 3

What are the two main important Trichostrongylus spp. that affect cattle?

Answer 3

(Ostertagia and Cooperia, there are other species present that contribute to parasitic gastroenteritis but rarely are the primary pathogens)

Question 4

(T/F) Most strongylid eggs in the manure of young cattle are Cooperia spp.

Answer 4

(T)

Question 5

The macrocyclic lactone dose for the treatment of Cooperia spp. in cattle is higher/lower (choose) than that needed to treat Ostertagia.

Answer 5

(Higher)

Question 6

Why are Trichostrongyle infections greatest in younger cattle?

Answer 6

(Bc immunity develops over several years)

Question 7

What results from subclinical Trichstrongyle infections?

Answer 7

(Decreased weight gain and growth from anorexia and gastric disturbance)

Question 8

Trichostrongylus spp. infections typically are subclinical but when they become clinical, what signs do you typically see?

Answer 8

(Diarrhea, weight loss, unthriftiness, and hypoproteinemia)

Question 9

What dewormer drug class is available in pour on formulas?

Answer 9

(Macrocyclic lactones → ivermectin, doramectin, eprinomectin, and moxidectin all have pour on formulas (as well as injectable))

Question 10

What dewormer drug classes are available in oral formulas?

Answer 10

(Benzimidazoles (fenbendazole, albendazole, oxfendazole) and nicotinics (levamisole, morantel))

Question 11

Parasite impact is higher on dairy/beef (choose) productions.

Answer 11

(Beef)

Question 12

Anthelmintic resistance is an issue for all three of the major drug classes but is particularly bad for which drug class?

Answer 12

(Macrocyclic lactones → it is heavily used d/t pour on convenience and low cost)

Question 13

How is anthelmintic resistance tested for in cattle?

Answer 13

(Fecal egg count reduction test → looking for drug efficacy over 90%)

Question 14

How long should you wait before taking your comparison fecal egg count reduction test sample when testing a macrocyclic lactone? What about a benzimidazole?

Answer 14

(ML → 14-17 days (moxidectin 17-21), BZD → 10-14 days)

Question 15

If your reduction in fecal egg count is 90% after using an anthelmintic, would you say that drug has:

A - Full efficacy
B - Possible resistance
C - Likely resistance
D - Highly likely resistance

Answer 15

(B, 95% and above is full efficacy, 90-95% is possible resistance, 80-90% is likely resistance, and <80% is highly likely resistance)

Question 16

What is the main way producers are getting around anthelmintic resistance in their cattle?

Answer 16

(Combination treatment with two different drug classes)

Question 17

(T/F) Oral administration is the most effective treatment route for intestinal parasites.

Answer 17

(T)

Question 18

What practices can be put in place to minimize resistance to extended release eprinomectin?

Answer 18

(Do not use year after year as a sole method, consider combination treatment, leave a refugia, and use other methods of parasite control such as pasture management)

Question 19

What is the main strategy used to maintain refugia in cattle?

Answer 19

(Selective non-treatment → leave 10-20% of the animals untreated; cannot easily ID animals that need tx bc fecal egg counts are not predictive and neither are using their weights)

Question 20

Haemaphysalis longicornis is the vector for which disease?

Answer 20

(Theileria orientalis)

Question 21

When is Haemaphysalis longicornis active during the year?

Answer 21

(March-November)

Question 22

How does Haemaphysalis longicornis reproduce?

Answer 22

(Parthenogenetically)