Canine/Feline Trematodes Flashcards
Alaria spp.-Common Name
Intestinal Fluke
Alaria spp.-Hosts
DH: Dogs and Cats
IH: Snails and Frogs (tadpoles)
PH: Frogs, snakes, rodents, birds, humans
*Zoonosis
Alaria spp.-Identification
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
Alaria spp.-Life Cycle
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
Alaria spp.-Site of Infection
Small Intestine
Immature stages in lungs
Alaria spp.-Pathogenesis and Lesions
Heavy infection can cause duodenitis
Lung migration cause clinical illness
Alaria spp.-Clinical Signs
Usually asymptomatic in DH
Alaria spp.-Diagnosis
Fecal sedimetation
Alaria spp.-Treatment and Prevention
Praziquantal or other cestocide
Nanophyetus salmincola-Common Name
Salmon Poisoning Fluke
Nanophyetus salmincola-Hosts
DH: Dogs and Cats
IH: Snails and fish
*Zoonosis
Nanophyetus salmincola-Identification
Adults: Ovoid, creamy white, up to 2 mm
Eggs: Oval, yellowish brown, thick shell, 80 um
Nanophyetus salmincola-Life Cycle
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
Nanophyetus salmincola-Site of Infection
Small Intestine
Nanophyetus salmincola-Pathogenesis and Lesions
Extremely pathogenic.
Vectors of rickettsial organism which causes severe hemorrhagic enteritis in dogs (“Salmon poisoning”)
Nanophyetus salmincola-Clinical Signs
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
Nanophyetus salmincola-Diagnosis
Fecal sedimentation
Nanophyetus salmincola-Treatment and Prevention
Trematocidal anthelmintics
Treat rickettsial organisms with tetracyclines
Paragonimus kellicotti-Common Name
Lung Fluke
Paragonimus kellicotti-Hosts
DH: dogs and cats
IH: Snails and Crayfish
Paragonimus kellicotti-Identification
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
Paragonimus kellicotti-Life Cycle
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
Paragonimus kellicotti-Site of Infection
Lung parenchyma
Paragonimus kellicotti-Pathogenesis and Lesions
Formation of cysts
Paragonimus kellicotti-Clinical Signs
Absent but intermittent cough may occur.
Heavy infections may have severe cough, pneumonia and death
Paragonimus kellicotti-Diagnosis
Radiographic lesions reveal cysts in lungs
Can find eggs on fecal flotation but sedimentation is preferred
Paragonimus kellicotti-Treatment and Prevention
Praziquantel
Platynosomum fastosum-Common Name
Lizard Poisoning
Platynosomum fastosum-Hosts
DH: Cats
IH: Snail, crustacean
obligate PH: lizard, toad, geckos and skinks
Platynosomum fastosum-Identification
Adults: 8 mm in length
Eggs: Oval, brownish up to 50 um, medium thick shell, operculate
Platynosomum fastosum-Life Cycle
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
Platynosomum fastosum-Site of Infection
Bile Ducts
Platynosomum fastosum-Pathogenesis and Lesions
Hyperplasia of bile ducts, thickened bile ducts, obstruction of bile ducts and pancreas
Platynosomum fastosum-Clinical Signs
Mild infection tolerated
Heavy infection results in “lizard poisoning”, cirrhosis, jaundice (icterus), diarrhea, vomiting, lethargy, enlarged liver with distended abdomen, emaciation and death
Platynosomum fastosum-Diagnosis
Eggs on fecal sedimentation
NO eggs in feces if bile ducts are obstructed
Platynosomum fastosum-Treatment and Prevention
Cestocidal drugs (praziquantal), surgery considered
