Sheep Flashcards
What is the superfamily of teladorsagia circumcinta?
Trichostrongyloidea
What is the life cycle of teladorsagia circumcinta?
Eggs pass out in faeces, hatch and moult. L1-L3.
L3 migrates onto pasture and is ingested.
L3 exsheaths in rumen and enters gastric gland of the abomasum and moults to L5.
Emerges from the glands and migrates in lumen.
What is the pre-patent period of teladorsagia circumcinta?
16-21 days
How long can L3 of teladorsagia circumcinta hypobiose?
<6 months
What size is the male and female adults of teladorsagia circumcinta?
Male: 6-8mm
Female: 8-10mm
What is the pathology of teladorsagia circumcinta?
Developing larvae in gastric glands causes distension of the glands, thickened hyperplastic mucosa and sloughed epithelium.
What are the clinical signs of teladorsagia circumcinta?
Summer/Autumn Anorexia Intermittent diarrhoea Dehydration Weight loss Death High plasma pepsinogen
What is the epidemiology of type I teladorsagia circumcinta?
Affects lambs or sheep with no previous exposure.
Relaxation in ewe immunity around parturition lead to periparturient rise in eggs excreted by ewes.
Once temperatures are conducive, these eggs develop to L3 and infect the lambs.
Overwintered L3 from the previous year can also infect the lambs.
Epidemiology is dependant on the temperature in the region.
How can teladorsagia circumcinta be diagnosed?
Detection of eggs in faeces.
Detection of worms post-mortem.
How can the spread of teladorsagia circumcinta be controlled?
Anthelmintic prophylaxis.
So treat the ewe around lambing to prevent periparturient egg count rising.
Treat lambs through grazing season every 3 weeks.
Treat and move at weaning.
Move lambs off of contaminated pasture.
Alternate grazing of pastures.
What is the superfamily of haemonchus contortus?
Trichostrongyloidea
What is the life cycle of haemonchus contortus
Eggs in faeces, L1 hatch and moults to L3.
L3 migrates onto pasture and are digested.
L3 exsheaths in rumen and moult to L4 in abomasum.
What do the adult haemonchus contortus feed on?
Blood
What is the pre-patent period of haemonchus contortus?
16-21 days
May undergo hypobiosis for <6 months
What are the size of the adult worms of haemonchus contortus and where are they located?
2-3cm in the abomasum
What is the pathology of haemonchus contortus?
Adults lacerate the mucosa and ingests blood.
Leads to acute blood loss and anaemia.
What are the acute clinical signs of haemonchus contortus?
Very high infection intensity can lead to severe hemorrhagic gastritis.
Sudden death.
What are the sub-acute clinical signs of haemonchus contortus?
Anaemia
Oedema - sub-mandibular and ascites
Ewes may stop their production of milk -> lamb death.
What are the chronic clinical signs of haemonchus contortus?
Low burdens, but continual loss of blood leads to: Weight loss Weakness Inappetence Chronic anaemia
What is the epidemiology of haemonchus contortus?
High biotic potential.
Rapid development in warm, humid conditions. So disease can appear suddenly.
Eggs/larvae do not overwinter, hypobiosis and re-emergence is due to spring contamination of pasture.
Mid-spring -> late autumn
No strong immunity.
How can haemonchus contortus be diagnosed?
History and clinical signs are sufficient alone.
Faecal egg count.
Post-mortem exam: abomasal haemorrhage, adults in abomasum, bone marrow expansion.
How can haemonchus contortus be controlled?
Treat and move
Anthelmintic prophylaxis is used to treat ewes for hypobiosed larvae/periparturient rise
During optimal conditions, it may need to be treated every 2-4 weeks.
What is the super family of nematodirus battus?
Trichostrongyloidea
What is the life cycle of nematodirus battus?
Eggs are passed in faeces.
L1-L3 develop in the egg.
L3 hatch due to climatic stimulus (cold snap followed by temperatures >10 degrees)
L3 exsheaths in rumen.
Moults to L4 in the small intestine mucosa.
Moults to L5 in the lumen
