General

Question 1

Ovine parasitic gastroenteritis. Is this a major concern in the UK

Answer 1

• Yes. About 53% of all digestive tract disease reports in sheep are due to PGE.
• The cost to UK sheep farming is about 84 million pounds per year.

Question 2

Why are goats more susceptible to parasites than sheep

Answer 2

• Browsing animals
• Acquired immunity is less effective than seen in sheep

Question 3

What are some of the major contributing species to Ovine PGE?

Answer 3

• Teledorsagia circumcincta
• Nematodirus battus
• Trichostrongylus vitrinus

Question 4

Name some spp of sheep parasites covered in lecture and their site of infection.

Answer 4

1. Abomasum
   
   • Teledorsagia circumcincta
   • Trichostrongylus axei
   • Haemonchus contortus
2. Small Intestine
   
   • Nematodirus battus
   • Cooperia curticei
   • Trichostrongylus vitrinus
   • Trichostrongylus colubriformis
3. Large Intestine
   
   • Chabertia ovina
   • Oesophagostomum
   • Trichuris ovis (didn’t really discuss much)

Question 5

Is FEC and adult worm burden a linear relationship?

Why or why not?

How many animals should you collect from?

Answer 5

• No
• Depends on
  
  • number of adult parasites
  • level of host immunity (periparturient rise)
  • age of host
  • species of parasite (1)
  • stage of infection (2)
  • consistency of feces
• Collect from at least 10 animals in large groups. Collect from all animals in small groups. In large groups, collect a mixture from severely affected, moderately affected, and clinically normal animals.

(1) FEC doesn’t discriminate between different Trichostrongyle spp except Nematodirus (much larger). Culture to L3 stage to differentiate - different spp have different fecundity.
(2) Some dz syndromes are caused by pre-patent parasites so stage of infection is important - may not produce many eggs during pathogenic stage