HELMINTH

• Also known as flat worms

• Are hemaphroditic

• No body cavities

• Uses flame cells for excretion.

Tubellaria (Planarians)

Trematoda (Flukes)

Cestoda (Tapeworms)

Also known as planarians, they are non-parasitic helminths, resides in fresh water

• Also known as Flukes, they are parasitic, monozoic or have unsegmented body.

• Long & Narrow bodies (e.g. Schistosoma)

• Thickly fleshed (e.g. stomach flukes)

• Leaf-like (e.g. fasciola)

• They have NO alimentary tract and rely on their tegument (outer covering that absorbs nutrients) uses pincoytosis and diffusion.

Are known as tapeworms are parasitic, and polyzoic or have segmented body.

The classification of Class Trematoda based on LC (Flukes) are:

• Subclass of Class Trematoda that uses ONE HOST for reproduction

• Mostly parasitize fishes, amphibians and reptiles.

• LC is DIRECT no Intermediate Host

• Subcalss of Class Trematoda that needs MORE THAN ONE host for reproduction.

• An Endoparasite of Dom & Wild Animals.

• Exhibits Sexual reproduction in FH (In vertebrates)

• Exhibits Asexual rep in IH (In mollusks)

• more commonly seen in veterinary medicine

• Are Hermaphroditic endoparasites.

• Have indirect LC, involving sexual and asexual generations involving diff hosts.

Egg —> Miracidium —> Sporocyst —>
Redia —> Cercaria —>Metacercaria —>Marita —> Adult (EMSRCMMA)

young fluke

Classification of Flukes based on their tail

(Paragonimus spp.) Has small stumpy tail

No tail

Spiny tail

Classification of Flukes based on anatomical structure:

• E.g Cyclocoelum spp.

• WITH Oral sucker

• NO Ventral sucker

• E.g. Zygocotyle spp.

• With Oral Sucker

• Acetabulum found at the posterior end.

• E.g. is Alloglossidium spp.

• WITH oral and ventral sucker located away from posterior end.

• e.g Cyathocotyle spp.

• Type of distome that has the body split into distinct anterior and posterior portions.

• Echinostoma spp.

• WITH Spines surrounding oral sucker / head collars are present.

• E.g Schistosoma spp.

• Has strong oral sucker and acetabulum near the anterior end.

IH of Fasciola hepatica

FH of F. hepatica

Life cycle of F. hepatica usually last until ____

Miracidium of F. hepatica must find a snail host within how many hrs?

Sporocyst of F. hepatica needs what type of env. to become a Redia?

F. hepatica miracidium usually takes how many weeks to become a Metacercaria?

One miracidium of F. hepatica can produce how many metacercaria?

Predilection site of f. hepatica metacercaria / young flukes are found here and they will stay for about 6-8 weeks.

When F. hepatica becomes an adult, it will then go to which body organ?

Prepatent period of F. hepatica

Fasciola may cause this to sheeps, alpaca and llamas. It may become a subclinical infection in cattle.

• Occurs when >2000 fasciola metacercaria are ingested in short period.

• CS: Distended and painful abdomen, anemia, sudden death after 2-6 weeks of infection.

• Can be accompanied by infection w/ Clostridium novyi w/ css Black diseas. Proliferate on the lesions young fluke create on the liver parenchyma.

• Occurs when 500-1500 fasciola metacercaria are ingested over a longer period. CS: Hemorrhage in the liver, anemia, death 7-10 wks post infection.

• Occurs when 200-500 fasciola metacercaria are ingested over a longer period.

• CS: Unthriftiness, anemia, pipe stem liver, hepatic fibrosis, submandibular edema, reduced milk prod. - Most common form in the country

Diagnosis for Fascioliasis

TOC for fascioliasis

Is larger than F. hepatica and is more common in the PH with 3% in Cattle, 35% in Carabaos s (than F. hepatica 1% in Cattle, 7% in Carabaos)

Fasciola gigantica IH

Spp of Fasciola that occurs in the Bile ducts of elephants

Spp of Fasciola that occurs in the Hippopotamus in Africa

• Is under the Genus Fascioloides, lacks anterior Projecting Cone

• Share similar LC with Fasciola may reach 17 months before completion

• Requires colder habitat

• Except PPP is 30 weeks

• Low Pathogenicity And RARELY Css Death In Cattle.

• Problems Usually Are Confined To Liver Condemnation

• GOATS & SHEEP Severely Affected; However, Deaths Have Been Reported Due To The Migration Of These Flukes To Other Organs.

• Histologically, Infected Liver May Show Black, Tortuous Tracts Due To The Migration Of The Flukes.

• Css. BLACK PORPHYRIN PIGMENTS show up on liver

Main predilection site of Fascioloides magna

Fascioloides magna is also known as _________

Reservoir hosts of Fascioloides magna in the North american countries

Reservoir hosts of Fascioloides magna in the European countries

Intermediate host of Fascioloides magna

TOC for Fascioloides magna effective for white-tailed deer.

TOC for Fascioloides magna effective for red deer

TOC for Fascioloides magna effective in cattle.

TOC for Fascioloides magna effective for sheep

• Still under genus Fascioloides whose reservoir host are pigs and final hosts are man and dogs

• Mainly seen in small intestine of man.

• They infect final hosts through ingestion of Metacercariae that encyst on aquatic plants. PPP: 9-13 weeks

IH of Fasciolopsis buski

• Also known as Rumen flukes

• Conical (pear-shaped), thicker and fleshier than their relatives.

Are mainly parasites of the Ruminant Forestomach

Part of the Family Paramphistomatidae found on the liver and duodenum instead.

• Also known as Rumen Flukes

• Parasitize the rumen. - Resemble maggots.

• WELL-DEVELOPED ventral sucker is located at the posterior extremity.

• PPP: 7-10 WEEKS

• DOC: Oxyclozanide

• How long does it take for Miracidium of Parahistome need to become a cercaria?

• Spp of Paramphistomum/ Rumen fluke that parasitize the rumen of cattle, sheep, goat and deer.

• IH: Planorbis & Bulinus snails

• Spp of Paramphistomum/ Rumen fluke found in liver, bile ducts, gallbladder & duodenum of cattle and buffalo.

• IH: Galba snails

• Spp of Paramphistomum/ Rumen fluke found in Rumen of Cattle and goat.

• IH: Omphiscola snails

• Spp of Paramphistomum/ Rumen fluke found in Rumen and reticulum of sheep, goat & cattle.

• IH: Bulinus snails

• Parasitize the Large intestines of larger animals (horses, cattle, and pig)

• Also known as Intestinal fluke

• Have SHORT CONICAL ANTERIOR end and a large posterior discoid body.

• LC is COMPLETE

• Reported to cause colic, lethargy, and diarrhea in severe/ heavily infected cases.

• are mostly nonpathogenic

• Found in the intestines of horses, donkeys, & pigs.

• IH: Bulinus and Cleopatra snails.

• Found in the large intestine of elephants and horses;

• IH: Planorbis snails

• Found in the cecum and colon of humans and pigs.

• IH: Helicorbis snails.

• Found in the large intestine of cattle and buffalo.

• IH: Hippeutis and Polypylis snails.

• Also knowns as Pouched Amphistomes

• Characterized by their EXTREMELY LARGE VENTRAL POUCH that covers the ventral surface of the fluke.

• Mainly parasitize ruminants with the generas.

• IH: FRESHWATER SNAILS

• FH: CATTLE and BUFFALO

• Spp of Pouched Amphistomes occurs in the rumen and reticulum of ruminants.

• Spp of Gastrothylacidae/ pouched amphistomes occurs in the rumen, and duodenum of ruminants and rarely humans.

• Spp of Gastrothylacidae/ pouched amphistomes in the RUMEN of ruminants

• Characterized as Flukes with Head collars

• Are more elongated than their other relatives and their oral suckers are surrounded by HEAD COLLARS.

• The number of spines on their head collars can be used to differentiate spp.

• Have TWO IH:

• a.) Primary IH: Snails

• b.) Secondary IH: Fish or Frogs

• Eggs —> Miracidium —> Snail host

• PPP: 1-2 WEEKS

Cecaria of Echinostomatidae emerge from snail host and may infect or encyst on ______

_______________ of these echinostomatidae flukes generally cause no significant effect on hosts

_______________ of these echinostomatidae flukes leads to inflammation, enteritis, anemia, colic, diarrhea, and emaciation.

DOC: ORFA Oxyclosamide, Rafoxamide, Fenbendazole, Albendazole

Spp of Echinostomatidae that mainly parasitize birds

Spp of Echinostomatidae mainly parasitize fish-eating mammals.

• # of Head collars: 37 spines, some grouped as “corner spines”

• Spp of Flukes with head collars that occurs in CECA, CLOACA and RECTUM Waterfowls, Pigeons occasionally humans.

• 2nd IH: Tadpoles

• #of Head collars: 37 Spines w/ “double row” pattern.

• Occurs in the Small intestines of Ducks, Pigeons and Humans:

• Secondary IH: Fish

• #of Head collars: 45 spines with corner spines.

• Occurs in the Small intestines of Avian spp & humans

• IH: Snails, fish, shellfish and tadpoles

• No Head collars

• Occurs in the small intestine of man, dog, cat and rat.

• Infection in man is usually through ingestion of raw infected snails.

• 1st IH snail of Echinostoma ilocanum

• 2nd IH snail of Echinostoma ilocanum

• Head collars: 50 small spines

• Occurs in the Small intestines of Avian spp.

• IH: Snails, fish, shellfish and tadpoles

• Head collars: 27 spines

• Occurs in the Small intestines of Carnivorous mammals such as Cat, fox, mink, badger, otter and hedgehogs.

• 2nd IH: Tadpoles

• Head collar: 24 spines in a “single row.”

• Occurs in the Small intestines of Dog, cat, fox, and pig.

• Also known as Eye flukes

• ONLY have a SINGLE spp under this family that is of veterinary importance.

• Known as “ORIENTAL AVIAN EYE FLUKE”

• parasite of the conjunctival sac of chickens, ostriches, and wild birds.

• PATHOGENIC EFFECTS Causes Conjunctivitis, keratitis, watery discharge, and mild edema.

• TX: Repeated use of Levamisole

• What triggers the hatching of embryonated eggs of Philopthalmus gralli?

• Philopthalmus gralli miracidium will become a single redia after penetrating what spp snail host?

• Predilection site of P. gralli redia, that they will penetrate to release new rediae

What stage does the Philopthalmus skips?

New redia of philopthalmus will migrate into the digestive glands and after ____ days will produce cercariae

Where do Philophthalmus spp. encyst? When ingested?

Encysted metacercaria of philopthalmus will migrate within an hour to which parts of the avian spp?

• Characterized by their ABSENCE OF ORAL SUCKERS.

• Parasites of Aquatic Birds in the; body cavity, air sacs or nasal cavities.

• They are slightly flattened, lack an oral sucker and usually a ventral sucker

Two important genera of Family Cyclocoelidae

Which stage in the LC does the Cyclocoelidae fluke enters the host?

Familly cycloelidae lacks this stage in LC?

TRUE OR FALSE

• Cercariae of Family Cyclocoelidae will NOT LEAVE THE SNAIL HOST. They will encyst while w/in the host.