Parasites of Dogs and Cats: Trematodes

39 terms by spettis89 

Create a new folder

Advertisement Upgrade to remove ads

Exam 2

Alaria spp:
Taxonomy

-Class: Trematoda
-Order: Digenea
-Family: Diplostomatidae
-Genus species: Alaria spp.
-Common Name: Intestinal Flukes

Alaria spp:
Hosts

-Final Hosts: Dogs, cats, foxes and minks
-Intermediate Hosts: Freshwater snails and frogs (tadpoles)
-Paratenic Hosts: Frogs, snakes, mice, rats, birds and other small mammals (raccoon, opossums), reptiles, humans
-Zoonosis

Alaria spp:
Identification

-Adults: 10mm, pink or brown, oral and ventral suckers and cylindrical hind part
-Egg: large 130um, oval, honey color, medium thick shell, operculum distinct

Alaria spp:
Life Cycle

-Eggs passed in feces and hatch in water
-Miracidia emerge, penetrate the snail (first IH) and emerge as cercaria
-Cecariae encyst in frogs (second IH) as mesocercariae
-Paratenic host ingests infected frog with mesocercariae
-FH ingest second IH or PH, the mesocercariae penetrates the gut wall, migrates to the lungs and develop to juvenile fluke
-Juvenile fluke migrates to trachea, is swallowed and matures in the small intestine

Spirometra spp:
PPP

5 weeks

Spirometra spp:
Sites of Infection

-Adults in small intestine
-Immature stages in lungs

Spirometra spp:
Pathogenesis and Lesions

-Heavy infections of adults cause severe duodenitis in FH
-Lung migration causes clinical illness

Spirometra spp:
Clinical Signs

Usually not evident in FH, but can be serious in paratenic host

Spirometra spp:
Diagnosis

Fecal sedimentation for detection of eggs

Spirometra spp:
Treatment and Prevention

-Praziquantel
-Other cestocide (even though it is a trematode)

Nanophyetus salmincola:
Taxonomy

-Class: Trematoda
-Order: Digenea
-Family: Troglotrematide
-Genus species: Nanophyetus salmincola
-Common Name: Salmon poisoning fluke

Nanophyetus salmincola:
Hosts

-Final Hosts: Dogs, cats, minks, raccoons, skunks, coyotes and other fish eating mammals
-Intermediate Hosts: Snails and fish
-Zoonosis

Nanophyetus salmincola:
Identification

-Adults: ovoid, creamy white, up to 2mm
-Egg: oval, yellowish brown, thick shell, 80um

Nanophyetus salmincola:
Life Cycle

-Eggs passed in feces and hatch in streams and become miracidia and pentrate the snail
-Cercariae emerge from snail to penetrate a fish to form metacercariae in various tissues (primarily kidneys, muscles, fins) and live up to 5 years
-Final host ingest the IH, the juvenile fluke encysts and matures in the small intestine

Nanophyetus salmincola:
PPP

1 week

Nanophyetus salmincola:
Sites of Infection

Adults in small intestine

Nanophyetus salmincola:
Pathogenesis and Lesions

-Extremely pathogenic
-Flukes are vectors of a rickettsial organism which causes severe hemorrhagic enteritis in dogs only (salmon poisioning)

Nanophyetus salmincola:
Clinical Signs

-Large numbers may cause diarrhea
-Salmon poising disease causes hemorrhagic enteritis, lymoh node enlargement, sudden onset fever, vomition, diarrhea, weight loss and high mortality

Nanophyetus salmincola:
Diagnosis

Fecal sedimentation for detection of eggs

Nanophyetus salmincola:
Treatment and Prevention

-Trematocidal anthelmintics
-Treat rickettsial organisms with tetracyclines

Paragonimus kellicotti:
Taxonomy

-Class: Trematoda
-Order: Digenea
-Family: Paragonimidae
-Genus species: Paragonimus kellicotti
-Common Name: Lung Fluke

Paragonimus kellicotti:
Hosts

-Final Hosts: dogs, cats and other carnivores
-Intermediate Hosts: snails and crayfish
-Zoonosis (10 species of Paragonimus which infect humans)

Paragonimus kellicotti:
Identification

-Adults: Ovoid, 16mm, reddish brown, occur in pairs and look like coffee beans with spiny cuticle
-Cysts: soft to solid, dark red-brown to gray, up to 50mm diameter, most commonly in the right caudal lung lobe
-Eggs: oval, yellowish brown, up to 110um with distinct operculum

Paragonimus kellicotti:
Life Cycle

-Eggs pass from pulmonary cyst containing flukes to a bronchiole and are swept up tracheaobronchial tree, swallowed and passed out in feces
-Eggs hatch in water to become miracidia and penetrate the snail
-Cercariae emerge from snail, infect a crayfish and encyst as metacercariae (infective)
-FH ingests the crayfish and juvenile cyst excysts to the lungs and mature in lung parenchyma
-Pairs are found in cysts and adults live for up to 4 years

Paragonimus kellicotti:
PPP

4-10 weeks

Paragonimus kellicotti:
Sites of Infection

In cysts in the lung parenchyma

Paragonimus kellicotti:
Pathogenesis and Lesions

Developing flukes cause formation of a cyst

Paragonimus kellicotti:
Clinical Signs

-Absent but intermittent cough can occur
-Heavy infection lead to more severe cough, pneumonia and death

Paragonimus kellicotti:
Diagnosis

-Radiographis lesions reveal cysts in lungs
-Egg in fecal flotation, but frequently distorted by the solution
-Sedimentation is the method of choice

Paragonimus kellicotti:
Treatment and Prevention

-Praziquantel effective
-Access to hosts difficult to prevent, not easy to control

Platynosomum fastosum:
Taxonomy

-Class: Trematoda
-Order: Digenea
-Family: Dicrocoeliidae
-Genus species: Platynosomum fastosum

Platynosomum fastosum:
Hosts

-Final Hosts: cats
-Intermediate Hosts (2): First is a snail and Second is a crustacean
-Paratenic Hosts: Lizards, toads, geckos and skinks

Platynosomum fastosum:
Identification

-Adult: 8mm in length
-Eggs: oval, brownish, up to 50um, medium tick shell, operculate

Platynosomum fastosum:
Life Cycle

-Eggs pass in feces into water
-Snails ingest eggs and devlop into miracidia and become cercariae
-Cercariae emerge from snails which infect crustaceans
-Metacercariae encyst in crustaceans
-PH ingest the crustacean
-FH ingest the IH or PH and they develop into juvenile flukes, which migrate up the bile ducts

Platynosomum fastosum:
PPP

3 months

Platynosomum fastosum:
Pathogenesis and Lesions

Cause hyperplasia of the bile ducts, thickened bile ducts with obstruction

Platynosomum fastosum:
Clinical Signs

-Mild infection tolerated
-Heavy infection results in "lizard poisoning": cirrhosis, jaundice, diarrhea, vomitting, lethargy, enlarged palpabel liver with distended abdomen, emaciation and death

Platynosomum fastosum:
Diagnosis

-Eggs on fecal sedimentation exam
-If bile ducts are obstructed there will be no eggs in feces

Platynosomum fastosum:
Treatment and Prevention

-Cestocidal drugs used with mixed results
-Surgery

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set