Fasciolidae Flashcards
Species
- Fasciola hepatica
- F. gigantica
- F. magna
- F. buski
Definitive host for:
- Fasciola hepatica
- F. gigantica
- F. magna
- F. buski
-Sheep, cattle, ox, other ruminants
-Cattle, buffalo, sheep, goat
-Deer, cattle, horse, sheep, pigs
-Man, pig
Habitat for:
- Fasciola hepatica
- F. gigantica
- F. magna
- F. buski
-Bile ducts (liver)
-Bile duct (liver)
-Liver
-Small intestine
Intermediate host for:
- Fasciola hepatica
- F. gigantica
- F. magna
- F. buski
- Lymnea truncatula (amphibious)
-
L. auricularia
-Fossaria parva
-Planorbis spp. Segmentina spp.
Infection of a snail with one miracidium can produce over
600 metacercaria
The emergent juvenile fluke from the metacercaria, often called_______, then penetrates the intestine and migrates to the predilection site where it becomes adult after several weeks and commences to lay eggs thus completing the cycle.
-Marita
Acute fasciolosis
Traumatic hepatitis
Chronic fasciolosis
Fibrosis; hyperplastic cholangitis
Clinical signs of fasciolosis
-sudden death (acute fasciolosis in sheep)
-anemia (paleness of skin & m. membranes)
-hypoalbuminemia (edema, lack of vigor, wasting)
Diagnosis of Fasciolosis
-Demonstration of the large, unembryonated eggs in fresh feces with the help of the sedimentation method
Treatment for F. hepatica infection
-Albendazole— PO; 10mg/kg BW (cattle); 15mg/kg BW (sheep)
-Rafoxanide — 7.5mg/kg BW, PO
-Nitroxynil— 10mg/kg, SC
-Triclabendazole (Fasinex) —PO; 10mg/kg BW (sheep&goat); 12mg/kg BW (cattle)
Prophylaxis of F. hepatica
-Snail control
-Prevent animals from access to metacercariae
-Treatment of infected animals
-Adults in the bile ducts of domestic ruminants in the tropics (Phil. included)
-Much larger than F. hepatica with less developed ‘shoulders’
Fasciola gigantica
Life cycle similar to F. hepatica, although development in both definitive host and snail intermediate host takes longer and uses a different snail (Lymnea auricularia rubiginosa)
F. hepatica
Adults (100 mm long, 2-4.5 mm thick, 11-26 mm wide, and oval) in the liver of wild and domestic ruminants
F. magna
Life cycle of F. magna resemble Fasciola spp., and ______ is considered a reservoir host
White-tailed deer
Life cycle of F. magna resemble Fasciola spp., and ______ is considered a reservoir host
White-tailed deer
Adult flukes in cattle are inside a closed cyst so that eggs are rarely passed in feces
F. magna
In sheep & goats encapsulation of the fluke does not occur, the fluke intensively migrates in the liver causing tremendous damage
F. magna
While the eggs of F. magna resemble those of F. hepatica, this similarity is of limited use; eggs usually are not passed in cattle and sheep
True
Diagnosis of F. magna
-Recovery of the parasites at necropsy, as well as proper identification of F. hepatica or F. gigantica is necessary for definite diagnosis
-When domestic ruminants and deer share the same grazing areas, the presence of disease due to F. magna should be kept in mind.
-Mixed infections with * F. hepatica* occur in cattle
Tx of F. magna
-Oxyclozanide has been reported effective against F. magna in white-tailed deer
- Triclabendazole has been used in captive and free-ranging red deer
- Rafoxanide has been used successfully against natural infections in cattle
-Albendazole (7.5 mg/kg)
-Clorsulon (15 mg/kg), & Closantel (15mg/kg) have shown efficacy against this fluke in sheep.
Accidental host and reservoir host of F. buski
Man
Pigs
-Adults occur in small intestines of man and pigs
- Endemic in Thailand, Vietnam, China
-Life cycle similar to Fasciola spp.
F. buski
Metacercariae of F. buski occur in
Trapa natans & water chestnut