Final - Helminths Flashcards
(18 cards)
Phylum Acantocephala characteristics
- long, round, unsegmented body
- anterior spiny proboscis
- pseudocoel
- no digestive tract
- dioecious sexes
Phylum Platyhelminthes, Class Trematoda characteristics
- dorsoventrally flat, unsegmented body
- acoelomate
- incomplete digestive tract
- monecious with exceptions
Phylum Platyhelminthes, Class Cestoda characteristics
- dorsoventrally flat, segmented body
- acoelomate
- no digestive tract
- monecious
Phylum Nemathelminthes
- long, round, unsegmented body
- pseudocoel
- complete digestive tract
- dioecious sexes
Pseudocoelomate
- formed from blastocoel
- fluid filled hydrostatic skeleton
- no circulatory system
Aceolomate
- no cavity
- space filled with mesenchymal parenchyma and organs suspended in it
Nematode life cycle
universal:
- Eggs in feces
- convert to L1, L2, infective L3 in environment
- L3 is eaten, converts to L4, Immature adult, Mature adult in 2-3 weeks
Genra that cause ruminant strongyles
Haemonchus Ostertagia/Telodorsagia Trichostrongylus Cooperia Oesophagostomum (Nematodirus)
Ruminant strongyle genra found in abomasum
Haemonchus
Ostertagia/Telodorsagia
Trichostrongylus
Ruminant strongyle genra found in small intestine
Trichostrongylus
Cooperia
Ruminant strongyle genra found in Large intestine
Oesophagostomum
Important ruminant strongyle species for sheep/goats
Haemonchus contortus
Teladorsagia circumcincta
Important ruminant strongyle species for cattle
Ostertagia ostertagi
Ruminant strongyles prepatent period
2-4 weeks (unless larvae arrests)
HOT CON larvae survival in environment
- moisture seeking
- heap, humidity = more active, use nutritents faster
- can overwinter
Who is most likely to get ruminant strongyles?
- 1st year grazing calves, lambs, kids (IS not exposed yet)
- Bovine ostertagiosis also common in weanling/yearlings
- Haemonchosis common in adults
Clinical signs for ruminant strongyles
- Parasitic Gastroenteritis (hyperplastic gastritis, catarrhal enteritis)
- inappetence, rough hair coat, diarrhea, maybe anemia
- subclinical infection = production loss
Diagnose ruminant strongyles
- strongyle-type eggs on fecal float
- signs + grazing history + seasonality of parasite
- don’t always see parasites on necropsy
