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Written by Administrator-GL
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Thursday, 17 July 2008 |
THREADWORM
Strongyloides spp.
Strongyloides papillosus (Common Threadworm)
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This is the most common parasite that infect goats.
They are typically not a problem unless they multiply into large numbers.
Stress or illness allows the parasite to multiply in large numbers .
Studies show that apparently the eggs are not passed into the fetus en-utero,
but are commonly passed through the milk.
This parasite commonly affects young and weaned kids.
Often occurs in low rainfall areas where other parasites rarely occur.
(click to enlarge image)
Adult worms in folds of cecum
Strongylus vulgaris
A. Large buccal cavity (mouth)
B. Two ear shaped teeth
C. Gutter that runs down dorsal side of buccal cavity.
Photo credit: University of Pennsylvania
Life Cycle
Stage 1: Eggs are deposited in feces.
Stage 2:Larvae 1 (L1) hatches in 1-2 days
Stage 3: Stage 1 and 2 larvae molt into stage 3 larvae (L3) in 1 week.
They are infective by migration into body through the toes-between the claws of the hoof, (which mimicks foot rot) and less commonly by eating fouled feed.
Stage 4: Stage 3 larvae exsheaths in the stomach and small intestine and penetrate the gut wall for their molt into fourth stage larvae (L4).
L4 migrates in the walls of the arteries pass into the blood stream and go to the heart, then to the lungs where they emerge into the airways. They work their way or are coughed up to the trachea and finally end up in the intestines where in two to three weeks they develop into mature female worms. The larvae can also be passed from the blood stream into the milk infecting young animals while they nurse..
Infectious stage: 1 to 2 days
(Minimum number of days for parasite to reach infectious larval stage)
Prepatent period 8 to 14 days.
Prepatent - Period of time between introduction into the body and apparent symptoms
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Site of Infection: SMALL INTESTINE |
Symptoms of Infection:
- Typically symptoms do not appear unless there is heavy infestation
- Scours
- Loss of appetite
- Weight Loss
- Episodes of coughing
- Lethargy
- Extremely severe infestations you "may" see the worms in feces
- If you have a dozen or more eggs in the fecal exam- be assured you have a very heavy infestation
- Damage to intestinal walls
- Reduced fiber production
- Acute onset : loss of bloom, profuse scouring, dehydration- deatyh usually occurs 2-3 days after outbreak
EGG:
Post Mortem (Necropsy) Findings:
- Clustered masses of tangled worms in ulcerative colon
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Additional Information:
Strongylus vulgaris UMCVM
Strongylus vulgaris
Large Strongyles of Horses
The Parasite
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Last Updated ( Thursday, 17 July 2008 )
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