Changes

[[Image:Dirofilaria immitus.jpg|thumb|right|150px|''Dirofilaria immitus'' - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine]]

[[Image:Dirofilaria immitus.jpg|thumb|right|150px|''Dirofilaria immitus'' - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine]]

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.).

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.).

== General Appearance ==

== General Appearance ==

*Non-bursate.

*Non-bursate

*Typically, they are long (up to 12cm or more), but filamentous.

*Typically, they are long (up to 12cm or more), but filamentous

*Live in connective tissues.

*Live in connective tissues

*(The most important veterinary species is ''Dirofilaria immitis'' which lives in the right heart and pulmonary arteries).

**The most important veterinary species is ''Dirofilaria immitis'' which lives in the right heart and pulmonary arteries

 

== General Life-Cycle ==

== General Life-Cycle ==

*The females of most species do not produce eggs, but instead they produce motile embryos ('''microfilariae''').

*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

*Female worm → microfilariae → accumulate in blood or tissue fluid

→ enters wound

→ enters wound

→ larvae develop and migrate to predilection site in final host.

→ larvae develop and migrate to predilection site in final host

 

 

 

 

 

 

[[Dirofilaria immitis]]

[[Dirofilaria immitis]]

[[Stephanofilaria spp.]]

[[Stephanofilaria spp.]]

*''Filaroides osleri'' causes infection in [[Respiratory Parasitic Infections - Pathology#Filaroides osleri|trachea]]

*''Filaroides osleri'' causes infection in [[Respiratory Parasitic Infections - Pathology#Filaroides osleri|trachea]]in gogs

*''Dirofilaria immitis'' live in heart and [[Respiratory Parasitic Infections - Pathology#Dirofilaria immitis|pulmonary arteries]] of dogs and cats

*''Dirofilaria immitis'' live in heart and [[Respiratory Parasitic Infections - Pathology#Dirofilaria immitis|pulmonary arteries]] of dogs and cats