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Flashcards

Endoparasites

Alice Butterworth Vet Med 2 English 64 cards

Teladorsagia circumcincta 1cm slender, pinky brown Cervical papillae Males have bursa + spicules

Cards in this deck (64)

  1. 1How can parasites harm their host?Numbers of parasites
    Competition for nutrients
    Feeding habits
    Site of infection
  2. 2How do parasites avoid destruction inside host?Evading immune system
    Suppress/ Manipulate the host immune response
  3. 3Worms in the abomasum of sheepHaemonchus contortus
    Teladorsagia circumcincta
    Trichostrongylus axei
  4. 4Worms in the small intestine of sheepNematodirus spp
    Trichostrongylus spp
    Cooper spp
  5. 5Worms in large intestine of sheep and cattleChabertia spp
    Oesophagostomum spp
    Trichuris spp
  6. 6—Teladorsagia circumcincta
    1cm
    slender, pinky brown
    Cervical papillae
    Males have bursa + spicules    Teladorsagia circumcincta 1cm slender, pinky brown Cervical papillae Males have bursa + spicules
  7. 7Life cycle of trichostrongyle sppDirect life cycle
    Adult worms in abomasum mate
    Females produce eggs
    Eggs develop in faeces (L1-L3)
    L3 released from faces by rain
    L3 = infective
    L3 eaten + reaches abomasum then burrows into gastric glands
    Develops (L3-L5)
    L5 emerge into lumen of abomasum
    Maturation into adult worm
    PPP 3 weeks
  8. 890umTrichostrongyle eggs
    Barrel shaped
    Undifferentiated - contain undeveloped morula    90um
  9. 9Pre-patent period (PPP)Time taken from the time of infection to the detection of eggs in the faeces
  10. 10A patent infectionAn infection that can be detected
  11. 11How does teladorsagia circuncinta cause disease?Associated with large numbers of developing larva (40,000+)
    Damage caused by developing larvae in gastric glands + emerging L5
    Parietal cells replaced by undifferentiated epithelial cells
    Loss of acid production
    Inc in abomasal pH
    Loss of bacteriostatic effect
    No conversion of pepsinogen to pepsin
    Inc permeability of mucosa
  12. 12Clinical signs of PGEProfuse watery diarrhoea
    Weight loss
    Inappetance
    Dehydration
    Death
  13. 13Sub-clinical signsPoor weight gain
    Reduced appetite +food intake
    Loss of plasma proteins into GI tract
  14. 14What sheep are usually affected by PGE ? and when ?Type 1
    First season grazing lambs
    Mid summer onwards
    Type 2
    Due to hypobiosis of L3 in autumn
    Simultaneous emergence of L5 in
    Yearling animals
    Late winter
  15. 15HypobiosisThe arrested development of larvae within the host - in response to a trigger received by the free living L3
  16. 16What triggers hypobiosis in teladorsagia circumcincta ?Drop in ambient temp in autumn
  17. 17Species that contribute to PGETeladorsagia circumcinta
    Trichostrongylus spp
    Cooperia spp
    Exceptions !
    Nematodirus battus
    Haemonchus contortus
  18. 180.5cmTrichostrongylus spp
    Diagnostic feature = excretory notch    0.5cm
  19. 19Site of trichostrogylus axei infectionAbomasum
  20. 20Clinical signs of trichostrongylus axei infection.Can cause PGE - so same as PGE
    Weight loss/ Poor weight gain
    Poor skeletal growth
    BLACK SCOUR
  21. 21Trichostrongylus spp life cycleSimilar to t. circumcincta
    Hypobiosis
    L3 overwinter
  22. 22Trichostrongylus spp pathogenesisLarvae develop deep in mucosa
    Sub epithelial tunnels
    Villous atrophy
    Oedema
    Haemorrhage
    Diarrhoea
  23. 23When is disease caused by trichostrongyle spp usually seen ?Autumn disease of store lambs
    Climate change!- seeing in summers and after mild winters, Severe disease in winter spring.
  24. 24—Cooperia spp
    "Watch spring" worm
    Cephalic vesicle
    Male has short stumpy spicules    Cooperia spp "Watch spring" worm Cephalic vesicle Male has short stumpy spicules
  25. 25Pathogenesis of cooper sppMild pathogen
    Can affect weight gain
    Heavy infections
    Catarrhal enteritis
    Villus atrophy
    Oedema of intestinal mucosa
  26. 26Worms in abomasum of sheep and cattleHaemonchus contortus
    Teladorsagia circumcinta
    Trichostrongylus axei
  27. 27Worms in the small intestine of sheep and cattleNematodirus spp
    Trichostrongylus spp
    Cooperia spp
  28. 28Worms in the large intestine of sheep and cattleChabertia spp
    Oesophagostomum spp
    Trichuris spp
  29. 29Sources of infection of PGEPPR in ewes
    Hypobiosis of larvae
  30. 30Over dispersionSmall proportion of the host population carries the majority of the parasite population
    20% of population sheds 80% of the eggs
  31. 31PPRPeri-parturient rise
    Reduced immunocompetence around parturition
    2w before lambing, 6w after lambing
  32. 32YEAR WITH T.circYEAR WITH T.circ
  33. 33SpringOverwintered L3 on grass
    Ewes turned out w lambs
    Ewes contaminate pasture. (PPR)
  34. 34May/JuneEwe = main source of infection
    Eggs shed on pasture start to develop
    Lambs start to graze + ingest overwintered L3
    Eggs shed from lambs onto pasture
  35. 35June/julyTemp sarts to inc so egg development speeds up
    Large numbers of L3 appear on pasture
  36. 36Aug/SeptDisease seen in lambs
  37. 37—Nematodirus baths
    2cm long
    Often found in tangled groups of worms like cotton wool
    Cephalic vesicle
    Males have long thin spicules
    Females have large eggs within uterus    Nematodirus baths 2cm long Often found in tangled groups of worms like cotton wool Cephalic vesicle Males have long thin spicules Females...
  38. 38Where is nematodirus battus found in the host?Small intestine
  39. 39—Nematodirus battus Eggs
    L1-L3 develops within the egg    Nematodirus battus Eggs L1-L3 develops within the egg
  40. 40N.battus life cycleUnembryonated eggs shed in faeces
    L3 develops in egg
    L3 hatches
    (L3 infective stage)
    L3 ingested
    L3-L4 in SI lumen
    L4 burrows into mucosa of SI
    L4-L5
    L5 emerges and adults mature in SI
    PPP 15d
  41. 41Pathology of N.battusDeveloping L5 destroy the mucosa
    Catarrhal enteritis
    Villous trophy
    Fluid + Nutrient absorption disrupted
    2000 worms can cause clinical disease
  42. 42Clinical sigs of N.battusSudden outbreaks of acute watery diarrhoea
    Inappetence
    Dehydration (Thirsty!)
    Abdominal pain
    Weight loss
  43. 43When is disease caused by N.battus?Lambs around 4-12weeks
    Often starts in PPP
  44. 44How many eggs per gram indicate its a heavy infestation of N.battus?Mean WEC>500epg
  45. 45Hatching requirements of N.battusExposure prolonged period of chill
    Exposure to mean day/night temp of 10degrees C
  46. 46For N.battus disease to occur hatching must coincide wPresence of susceptible lambs
    Old enough to graze
    Before age immunity develops
  47. 47Are ewes a large source of infection?No
    Strong acquires immunity therefor ewes not affected
    Lamb to lamb cycle!
  48. 48How do you control N battusGrazing management
    Prophylactic Tx (NOT susceptible to injectable MLS)
  49. 49Changing epidemiology of N.battusMoe outbreaks in autumn due to eggs passed that summer hatching w/o need for chilling and warming
  50. 50—Haemonchus contortus
    Large 3cm
    Cervical papillae
    White ovaries wrapped around gut (Barbers pole)
    Assymetrical dorsal lobe    Haemonchus contortus Large 3cm Cervical papillae White ovaries wrapped around gut (Barbers pole) Assymetrical dorsal lobe
  51. 51Life cycle of haemonchus contortusTypical trichostrongyle
    PPP - 3wks
    Larvae develop in mucosa
    Adults are blood feeders
    Hypobiosis
    L3 don't survive winter in UK
  52. 52Pathogenesis of H.contortusAdults feed on blood
    Erosion of abomasal wall
    Severe haemorrhage gastritis
  53. 53Clinical signs of H.contortusSevere anaemia
    Oedema
    Weight loss
  54. 54Are ewes a source of infection of haemonchus contortus?Yes - Ewes are the main source of pasture contamination
  55. 55When is disease caused by H.contortus seen?Late summer
  56. 56Haemonchus controlBZs white drenches
    LEV/PYR yellow drenches
    MLs clear drenches
    AAD -monepantel
    Derquantel + Abamectin
    Vaccine?
  57. 57Dx PGEClinical signs -Diarrhoea, poor weight gain/weight loss
    Season - August/Sept
  58. 58Nematode species that cause PGET.circumcincta
    Trichostrongylus spp
    Cooperia spp
    H.contortus
  59. 59Control - Pre parasitic stagesFaecal removal - not practical for ruminant systems
    Grazing management
    Biological control - nematode trapping fungi
  60. 60Control - parasitic stagesGenertically mediated host resistance
    Anthelmintics vaccination
  61. 61Control of PGEQuarantine incoming animals
    Test for anthelmintic resistance
    Correct administration of drugs
    Only use drugs were necessary
    Choice of anthelmintic
    Preserve refugia population
  62. 62Management of resistant parasitesDrug prophylaxis
    Clean pasture
    Safe pasture
    Rotation w crops/other stock
  63. 63Clean pastureNon grazed by sheep for previous 12 m
  64. 64Safe pastureUsed the previous year, but safe beginning on June

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Vet Med 2 (Parasitology ) Flashcards on Endoparasites, created by Alice Butterworth on 12/12/2018.
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