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| + | The filarial worms are of great importance in human medicine in the tropics, causing diseases such as elephantitis and river blindness, but their veterinary interest is limited - with the important exception of ''Dirofilaria'', the canine heartworm, which is a major cause of morbidity and death in warmer, humid regions (including parts of the USA, Australia, southern Europe etc.). |
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| + | == General Appearance == |
| + | *Non-bursate. |
| + | *Typically, they are long (up to 12cm or more), but filamentous. |
| + | *Live in connective tissues. |
| + | *(The most important veterinary species is ''Dirofilaria immitis'' which lives in the right heart and pulmonary arteries). |
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| + | == General Life-Cycle == |
| + | *The females of most species do not produce eggs, but instead they produce motile embryos ('''microfilariae'''). |
| + | *Female worm → microfilariae → accumulate in blood or tissue fluid |
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| + | → taken up by biting arthropod intermediate host |
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| + | → L1 → L2 → L3 |
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| + | → enters wound |
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| + | → larvae develop and migrate to predilection site in final host. |
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| [[Dirofilaria immitis]] | | [[Dirofilaria immitis]] |