nematoda vmp 920 infection & immunity ii veterinary parasitology
TRANSCRIPT
![Page 1: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/1.jpg)
Nematoda
VMP 920Infection & Immunity II
Veterinary Parasitology
![Page 2: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/2.jpg)
Haemonchus contortus
Barber-pole worm (Haemonchosis) Morphology
Dimorphic Male (bursate) & Female Nematodes
![Page 3: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/3.jpg)
Life Cycle
Life cycle image
![Page 4: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/4.jpg)
Life Cycle
Direct Life Cycle (Goats & Sheep - abomasum)• Transmission -- ingestion of infective larvae (L3)
(deadly dew-drop)
• From eggs in feces to infective L3 takes 4-6 days on pasture
• Pasture-borne parasite
• 3 week prepatency• But peracute dz in young hosts in less than 1
week
![Page 5: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/5.jpg)
Life Cycle
Arrested (hypobiotic) larvae in host• Survive harsh seasons• Periparturient rise “targets” very young
animals• Premunition
• Inhibits development of arrested larvae• May result in Post-treatment DZ
![Page 6: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/6.jpg)
Pathology
• Hemorrhagic anemia• Hypoproteinemia
Severe pallor (anemia)Facial edema“Bottle-jaw”
![Page 7: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/7.jpg)
Pathology
Morbidity & Mortality
![Page 8: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/8.jpg)
Pathology@ necropsy
Severe pallor (anemia)throughout organs
Very thin, non-clotting blood
Abundant wormsin abomasum
![Page 9: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/9.jpg)
Pathology – Peracute DZ
• “extremely large number of immature worms”
• FWEC = 0 epg to very low epg (eggs per gram
of feces)
• young goats, lambs exsanguinated before worms mature.
• Severe hemorrhagic gastritis.• May remove 1/5 of circulating erythrocyte volume per day.
• Sudden death from acute blood loss.
![Page 10: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/10.jpg)
Pathology – Acute DZ
• 1,000 to 10,000 worms• FWEC = As high as 100,000 epg• Young susceptible animals become heavily infected.
• Anemia develops rapidly.• Expansion of the erythropoietic response.
• Generalized anemia and hypoproteinemia.
• May remove 1/10 of circulating erythrocyte volume per day.
![Page 11: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/11.jpg)
Pathology – Chronic DZ
• 100 to 1,000 worms• FWEC = <2,000 epg• Older animals• 100% morbidity but low mortality• Morbidity depends on animal’s
erythropoietic capacity, iron and nutritional metabolic reserves.
• Anemia & Hypoproteinemia may or may not be severe.
![Page 12: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/12.jpg)
Clinical Signs & Diagnosis
• Signs of anemia, tarry feces, pale mucus membranes, bottle-jaw, (not diarrhea)
• McMasters = Fecal Worm Egg Count (FWEC)
• At what FWEC would you treat?
• Resistance/Efficacy check with McMasters.
• FAMACHA = “Grade” of pale mucous membranes
![Page 13: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/13.jpg)
Clinical Signs & Diagnosis
SHEEP or GOAT
![Page 14: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/14.jpg)
Clinical Signs & Diagnosis
Normal feces
![Page 15: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/15.jpg)
Clinical Signs & Diagnosis
McMasters Quantitation
Fecal Worm Egg Count(FWEC)
Strongyle-type eggs
![Page 16: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/16.jpg)
Clinical Signs & Diagnosis
FAMACHA is an acronym derived from the name of the creator of this system, Dr. Faffa Malan; CHA stands for chart.
FAMACHA
For Grading pallor of mucous membranes
![Page 17: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/17.jpg)
Treatment
• Fenbendazole, Pyrantel, Ivermectin, etc.
• Dewormer Resistance a major problem
• Spring treatment of pregnant females to target periparturient rise.
![Page 18: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/18.jpg)
Control• Pasture “Sanitation” (impractical)• Regular scheduled Deworming [Ex. Deworm
monthly] (may result in resistance)• Pasture rotation (requires 2-6 month rest =>
much land needed)• Co-species grazing• Test (McMasters) & Treat (selective deworming)• FAMACHA, Test & Treat (selective deworming) – provides refugia => inhibit large population of resistant
worms. - slows development of resistant worm
population
![Page 19: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/19.jpg)
Control: McMasters
McMasters Quantitation
Strongyle-type eggs
• Use for making selective deworming decisions• deter resistance & promote refugia
• Use to identify hosts that shed a lot of worm eggs• Use to determine dewormer efficacy
![Page 20: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/20.jpg)
Control: FAMACHA
• Use for tactical deworming• Use for making selective deworming decisions
• deter resistance & promote refugia
![Page 21: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/21.jpg)
Control
• Refugia image
![Page 22: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/22.jpg)
Challenges to Control
Infective Larvae on Pasture
Hypobiotic Larvae in Host
Worm resistance to Dewormers
Prevent “contamination” of pasture & host through selective strategic deworming.
![Page 23: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/23.jpg)
Important Points Direct Life Cycle – Pasture-borne parasite (L3) (deadly-
dewdrop) Sanitation by deworming strategy.
Special life cycle concerns: Prepatent period, Hypobiotic larvae “overwinter”, Peripartureint rise targets neonates.
Blood-feeding worms Pathology (Peracute, Acute,
Chronic) anemia. Clinical Signs.
Diagnostics: Response to treatment, McMasters & FWEC, FAMACHA
Control: Advantages & disadvantages of each control strategy.
Control: Understand concept of refugia to inhibit resistant populations
![Page 24: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/24.jpg)
EquineSmall Strongyles
over 40 species Dimorphic Male (bursate) & Female
Nematodes
![Page 25: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/25.jpg)
Life Cycle
Life cycle image
![Page 26: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/26.jpg)
Life Cycle
Direct Life Cycle (Horse – large intestine)• Transmission -- ingestion of infective larvae (L3)
(deadly dew-drop)• From eggs in feces to infective L3 takes 4-6 days
on pasture• Pasture-borne parasite• 2.5 to 3 months prepatency
![Page 27: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/27.jpg)
Life CycleArrested (hypobiotic) larvae in host• Premunition inhibits development
• “prepatency” of arrested larvae - as few as 18 days post-
reactivation
• Post-treatment DZ • Periparturient rise “targets” very
young animals
![Page 28: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/28.jpg)
Pathology
Mainly caused by emerging larvae.• Acute -- severe enteritis &
diarrhea, hypoalbuminemia
• Post-treatment -- severe enteritis, colitis & diarrhea, hypoalbuminemia
• Chronic -- granulomatous colitis
![Page 29: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/29.jpg)
ACUTE
![Page 30: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/30.jpg)
![Page 31: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/31.jpg)
![Page 32: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/32.jpg)
![Page 33: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/33.jpg)
Pathology
Severe Colitis
![Page 34: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/34.jpg)
Clinical Signs & Diagnosis
• Persistent diarrhea, edema, poor body condition, COLIC
• McMasters = Fecal Worm Egg Count (FWEC)• At what FWEC would you treat?
• Will only show adult burden, not DZ causing emerging larvae.
• Resistance check with McMasters.
![Page 35: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/35.jpg)
Clinical Signs
Signs of colic
Diarrhea
![Page 36: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/36.jpg)
Diagnosis
McMasters Quantitation
Fecal Worm Egg Count(FWEC)
Strongyle-type eggs
(maybe negativein acute pathology)
![Page 37: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/37.jpg)
Treatment
• Fenbendazole, Pyrantel, Ivermectin, etc.
• Dewormer Resistance a major problem
![Page 38: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/38.jpg)
Control• Pasture “Sanitation” (removal of feces)• Regular scheduled Deworming [Ex. Deworm
every 2 months] (may result in resistance)• Pasture rotation (requires months of rest =>
much land needed)• Co-species grazing• Test (McMasters) & Treat – provide refugia => inhibit large population of resistant worms. - slows development of resistant worm population
![Page 39: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/39.jpg)
![Page 40: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/40.jpg)
Challenges to Control
Infective Larvae on Pasture
Hypobiotic Larvae in Host
Worm resistance to Dewormers
Prevent “contamination” of pasture & host through selective strategic deworming.
![Page 41: Nematoda VMP 920 Infection & Immunity II Veterinary Parasitology](https://reader036.vdocument.in/reader036/viewer/2022062313/56649cc95503460f94991d6b/html5/thumbnails/41.jpg)
Important Points
Direct Life Cycle – Pasture-borne parasite (L3) (deadly-dewdrop) Sanitation by deworming strategy.
Special life cycle concerns: Prepatent period adult worms & Arrested larvae, Hypobiotic larvae “overwinter”, Peripartureint rise target young, Premunition + Arrested larvae Post-treatment DZ
Emerging larvae Pathology (Acute, Post-treatment, Chronic),
Clinical Signs – COLIC, Enteritis Diagnostics: McMasters & FWEC, Control: Advantages & disadvantages of each control
strategy. Control: Understand concept of refugia to inhibit
resistant populations