Canine/Feline Trematodes

Question 1

Alaria spp.-Common Name

Answer 1

Intestinal Fluke

Question 2

Alaria spp.-Hosts

Answer 2

DH: Dogs and Cats
IH: Snails and Frogs (tadpoles)
PH: Frogs, snakes, rodents, birds, humans
*Zoonosis

Question 3

Alaria spp.-Identification

Answer 3

Adults: 10 mm, pink or brown, oral and ventral suckers and a cylindrical hind part
Eggs: Oval, honey color, 130 um, medium thick shell, operculum

Question 4

Alaria spp.-Life Cycle

Answer 4

Indirect. PPP = 5 wk.
Egg passed in feces→hatch in water→miracidia emerge and penetrate snail→emerge as cercaria→cercaria encyst in frogs as mesocercariae→DH infected by ingesting IH with mesocercariae→mesocercariae penetrates gut wall and migrates to lungs→develop into juvenile fluke→migrates up trachea→swallowed→matures to adult in small intestine

Question 5

Alaria spp.-Site of Infection

Answer 5

Small Intestine

Immature stages in lungs

Question 6

Alaria spp.-Pathogenesis and Lesions

Answer 6

Heavy infection can cause duodenitis

Lung migration cause clinical illness

Question 7

Alaria spp.-Clinical Signs

Answer 7

Usually asymptomatic in DH

Question 8

Alaria spp.-Diagnosis

Answer 8

Fecal sedimetation

Question 9

Alaria spp.-Treatment and Prevention

Answer 9

Praziquantal or other cestocide

Question 10

Nanophyetus salmincola-Common Name

Answer 10

Salmon Poisoning Fluke

Question 11

Nanophyetus salmincola-Hosts

Answer 11

DH: Dogs and Cats
IH: Snails and fish
*Zoonosis

Question 12

Nanophyetus salmincola-Identification

Answer 12

Adults: Ovoid, creamy white, up to 2 mm
Eggs: Oval, yellowish brown, thick shell, 80 um

Question 13

Nanophyetus salmincola-Life Cycle

Answer 13

Indirect. PPP = 1 wk.
Eggs passed in feces→hatch in stream→miracidia emerge and penetrate snail→cercariae emerge from snail and penetrate fish→form metacercariae in various tissues (kidneys, muscles, fins)→DH ingest IH→juvenile fluke excysts and matures in small intestine of DH

Question 14

Nanophyetus salmincola-Site of Infection

Answer 14

Small Intestine

Question 15

Nanophyetus salmincola-Pathogenesis and Lesions

Answer 15

Extremely pathogenic.

Vectors of rickettsial organism which causes severe hemorrhagic enteritis in dogs (“Salmon poisoning”)

Question 16

Nanophyetus salmincola-Clinical Signs

Answer 16

Large number of flukes cause diarrhea
Salmon poisoning causes hemorrhagic enteritis, lymph node enlargement, sudden onset of fever, vomiting, diarrhea, weight loss, and high mortality

Question 17

Nanophyetus salmincola-Diagnosis

Answer 17

Fecal sedimentation

Question 18

Nanophyetus salmincola-Treatment and Prevention

Answer 18

Trematocidal anthelmintics

Treat rickettsial organisms with tetracyclines

Question 19

Paragonimus kellicotti-Common Name

Answer 19

Lung Fluke

Question 20

Paragonimus kellicotti-Hosts

Answer 20

DH: dogs and cats
IH: Snails and Crayfish

Question 21

Paragonimus kellicotti-Identification

Answer 21

Adults: ovoid, up to 16mm, reddish brown, occur in pairs, look like coffee beans with spiny cuticle
Cysts: soft to solid, dark red-brown to gray, up to 50mm commonly found in right caudal lobe of lung
Eggs: Oval, yellowish brown, up to 110 um with distinct operculum

Question 22

Paragonimus kellicotti-Life Cycle

Answer 22

Indirect. PPP = 4-10 wk.
Eggs pass from pulmonary cyst to a bronchiole→swept up tracheobrachial tree→swallowed→passed in feces→hatch miracidia once in water→penetrate snail→cercariae emerge and penetrate crayfish→encyst as metacercariae→DH ingests IH with metacercariae→juvenile excysts in intestines→penetrates gut wall and migrates peritoneal cavity to the lungs→mature to adults in lung parenchyma near bronchiole

Question 23

Paragonimus kellicotti-Site of Infection

Answer 23

Lung parenchyma

Question 24

Paragonimus kellicotti-Pathogenesis and Lesions

Answer 24

Formation of cysts

Question 25

Paragonimus kellicotti-Clinical Signs

Answer 25

Absent but intermittent cough may occur.

Heavy infections may have severe cough, pneumonia and death

Question 26

Paragonimus kellicotti-Diagnosis

Answer 26

Radiographic lesions reveal cysts in lungs

Can find eggs on fecal flotation but sedimentation is preferred

Question 27

Paragonimus kellicotti-Treatment and Prevention

Answer 27

Praziquantel

Question 28

Platynosomum fastosum-Common Name

Answer 28

Lizard Poisoning

Question 29

Platynosomum fastosum-Hosts

Answer 29

DH: Cats
IH: Snail, crustacean
obligate PH: lizard, toad, geckos and skinks

Question 30

Platynosomum fastosum-Identification

Answer 30

Adults: 8 mm in length
Eggs: Oval, brownish up to 50 um, medium thick shell, operculate

Question 31

Platynosomum fastosum-Life Cycle

Answer 31

Indirect. PPP = 3 mths.
Eggs passed in feces into water→Snails ingest eggs→develop into miracidia and become cercariae→cercariae emerge from snails and infect crustaceans→metacercariae encyst in crustacean→PH ingests crustacean with metacercariae→cat ingests infected PH→juvenile flukes migrate up bile ducts

Question 32

Platynosomum fastosum-Site of Infection

Answer 32

Bile Ducts

Question 33

Platynosomum fastosum-Pathogenesis and Lesions

Answer 33

Hyperplasia of bile ducts, thickened bile ducts, obstruction of bile ducts and pancreas

Question 34

Platynosomum fastosum-Clinical Signs

Answer 34

Mild infection tolerated
Heavy infection results in “lizard poisoning”, cirrhosis, jaundice (icterus), diarrhea, vomiting, lethargy, enlarged liver with distended abdomen, emaciation and death

Question 35

Platynosomum fastosum-Diagnosis

Answer 35

Eggs on fecal sedimentation

NO eggs in feces if bile ducts are obstructed

Question 36

Platynosomum fastosum-Treatment and Prevention

Answer 36

Cestocidal drugs (praziquantal), surgery considered