Nematode parasites of ruminants Flashcards
What is the most important gastrointestinal nematode infection in grazing ruminants?
The gastrointestinal nematode roundworm infection is the most important disease of sheep in Australia and also important in cattle is roundworms liver fluke and tapeworms
In sheep and cattle where is the barbers poll worm located
specific name is what
Abomasum
HAEMONCHUS CONTORTUS
In shape, where is the small Brown stomach worm found?
What is it specific name?
ABOMASUM
OSTERTAGIA
In shape where is the black scour worm found?
What is it specific name?
Small intestine
TRICHOSTRONGYLUS
In sheep, where is the thin necked intestinal worm found?
Specific name
Small intestine
NEMOTODIRUS
In sheep, where is the large bowel nodule worm found?
Specific name
Large intestine
OESOPHAGOSTOMUM
In shape where is the largemouth bowel worm found?
Specific name
Large intestine
CHABERTIA
In cattle, where is the small Brown stomach worm found?
Specific name
ABOMASUM
0STETAGIA
Where is the stomach hair worm found in cattle
ABOMASUM
In cattle where is the small intestinal worm found?
Small intestine
In cattle where is the nodule worm found?
Large intestine
What is the basic concept of nematode epidemiology?
Epidemiology is the study of factors that influence the expression of a disease in a population. A wide range of host environmental and parasite factors affect the occurrence of gastrointestinal nematoditis in cattle and sheep.
What are some basic concepts with nematode epidemiology, with calves
1.calves and lambs are born. Parasite free are infected from pastures.
2.most susceptible from birth until 12 to 15 months of age until immunity develops
3.cattle have the strongest immunity goats have the lowest immunity
Some nematode species include a period of arrested development at the stage L4 of the life cycle in the host what is the strategy known as and what does it enable the Nematode to do?
The strategy is known as hypobiosis and it enables the Nemo to survive over difficult periods. This is only seen in Abomasal parasites.
What are the two major factors affecting timing and success of the life cycle of a ruminant roundworm
Timing of the development advance depends on temperature (warmup means faster)
and success of developmental events depends on temperature and available moisture.
In the development to infective L3 stage describe the four steps
1.egg containing an embryo is passed into the faeces
2.1st stage lava L1 develops in the egg and hatches
3.L1 feeds on bacteria in faeces and enters and inactive period (lethargic) before malting to the L2
4.L2 feeds and grows enters second lethargus and undergoes an incomplete malt to L3. this is the ensheathed or infective L3 stage, cannot feed, dependent for survival on stored metabolites she protects it from desiccation
Briefly describe the persistence of the L3 on pasture
L3 leave manure, climb pasture or enter soil and weight indigestion by ruminant numbers can only decline. Resistant to dry out and cold, death rate increases with increasing temperature and humidity, typical half-life range 14 to 40 days.
Once in adult stage in sheep gut briefly describe
Sexual reproduction occurs and numerical numbers increase influenced by host immunity, approximately 18 days from injection of L3 egg to production, eggs in manure
Is there any multiplication of the parasites during the environmental phase?
No
What are the four key factors influencing the rate of development and survival of the egg? L1L2 and L3 larva?
Temperature, moisture availability, oxygen availability, exposure to UV radiation
What are the three distinct stages of an nematode life cycle?
Host, dung, pasture
