Ascaridoidea - cattle

Question 27

Where do Toxicara vitulorum parasites infect?

Are these large or small worms?

What is important about the eggs of this spp?

Answer 27

• SI
• Largest of the intestinal parasites in cattle (30cm)
• Thick, pitted shell. Highly resistant

Question 28

Does Toxicara vitulorum show tissue migration / ALD?

What is/are the route(s) of infection?

Is there an acquired immunity?

Answer 28

• Migration is possible in older cattle - important in trans-mammary passage of infection to calf.
• No migration in calf
• Oral / ingestion - larvated egg. No tissue migration in calf, but migration in older cattle (in females cattle, resumption of growth prepartum).
• Trans-mammary route
• There is exposue to infection from birth, but immunity is acquired.

Question 29

What is the pathogenesis of Toxicara vitulorum?

What is the most important feature in regards to epidemiology?

Answer 29

• Mainly pathogenic in cattle (esp buffalo) up to 6 months old.
• Pathogenesis is caused by the adult worms in the intestines
• Heavy infections are associated with poor thriving and intermittant diarrhea.
• In buffalo calves, fatalities may occur.
• The most important feature is ALD in the tissue, which when growth comenses prior to parturition, can lead to trans-mammary spread (the most important route of infection).