Canine/Feline Cestodes Flashcards
Dipylidium caninum-Common Name
Common tapeworm, cucumber tapeworm, double pored dog tapeworm, “creeping seeds”, flea tapeworm
Dipylidium caninum-Hosts
DH: dogs, cats
IH: Fleas (Ctenocephalides spp.) and louse (Trichodectes canis)
*Zoonosis
Dipylidium caninum-Identification
Adults: max length 50cm
Proglottid is elongate, has 2 sets of repro. organs with bilateral genital pores. Single segments passed
Eggs: packets 230 x 170 um containing 10-20 eggs 35-40 um
Dipylidium caninum-Life Cycle
Indirect. PPP = 21 days
Passed segments are active→egg packets expelled by active segment→IH ingests egg (oncosphere L1) (flea must be larval stage to ingest, louse in any life stage can ingest)→ oncospheres develop into cysticercoids in the abdominal cavity of IH→DH eats the IH
Dipylidium caninum-Site of Infection
Adults: in small intestine Larval stage (cysticercoid) in flea/louse
Dipylidium caninum-Pathogenesis and Lesions
Adults are largely non-pathogenic
Crawling segments may be uncomfortable
Dipylidium caninum-Clinical Signs
Excessive grooming of perineum, scooting anus on floor
Dipylidium caninum-Diagnosis
Presence of segments around perineum,
Adhesive tape or Scotch tape method: stick tape to perianal area, stick tape to slide and examine for eggs
Dipylidium caninum-Treatment and Prevention
Cestocide, flea control important.
Treatment of environment with insecticides to eliminate fleas/lice
Echinococcus granulosus-Common Name
Hydatid tapeworm
Echinococcus granulosus-Hosts
DH: Dogs
IH: herbivores and humans
*Zoonosis
Echinococcus granulosus-Identification
Adult: 6mm long with 3-4 segments, scolex with 4 suckers and 2 rows of hooks Hydatid cyst (w/in IH): brood capsules and scolices, fluid filled, 5-10cm but up to 50cm in diameter Eggs: 25-40 um in diameter, brown color, radial striations on shell, presence of 6 embryonic hooks
Echinococcus granulosus-Life Cycle
Indirect. PPP = 45-60 days
Adult sheds 1 gravid segment with eggs into feces→ develop into oncospheres that are viable in ground for up to 2 yrs.→IH ingests egg→ egg hatches→ hexacanth larva penetrates the intestine, migrates to liver and lungs of IH→ forms hydatid cyst→ grows and matures in 6-12 mths→ DH ingests infected IH→scolices evaginate and attach to the mucosa of the small intestine and mature in DH
Echinococcus granulosus-Site of Infection
Small intestine in DH.
Unilocular hydatid cysts in liver, lungs and other organs in IH and humans
Echinococcus granulosus-Pathagenesis and Lesions
Nonpathogenic within DH.
Within human IH, hydatid develops in pulmonary or hepatic site causing pathogenesis
Echinococcus granulosus-Clinical Signs
No clinical signs in DH.
In humans, respiratory symptoms and with many hydatids in the liver may cause gross abdominal distension
Echinococcus granulosus-Diagnosis
Eggs in fecal flotation or with Adhesive/Scotch tape method
Echinococcus granulosus-Treatment and Prevention
Anthelmintic treatment, removal of stray dogs, prohibition against feeding uncooked offal
Echinococcus multilocularis-Common Name
Alveolar hydatid tapeworm
Echinococcus multilocularis-Hosts
DH: Dogs and Cats
IH: Cows, equines, swine and rodents
*Zoonosis
Echinococcus multilocularis-Identification
Adult: 6mm long with 4-5 segments, scolex with 4 suckers and 2 rows of hooks Hydatid cysts (w/in IH): Alveolar hydatid cyst, not confined by a capsule, exogenous budding Eggs: taeniid type, brown, 25-40 um, radial striations in shell, 6 embryonic hooks
Echinococcus multilocularis-Life Cycle
Indirect. PPP = 28 days
Adult sheds 1 gravid segment with eggs into feces→ develop into oncospheres that are viable in ground for up to 2 yrs.→IH ingests egg→ egg hatches→ hexacanth larva penetrates the intestine, migrates to liver and lungs of IH→ forms hydatid cyst→ grows and matures in 6-12 mths→ DH ingests infected IH→scolices evaginate and attach to the mucosa of the small intestine and mature in DH
Echinococcus multilocularis-Site of Infection
Adults: Small intestine
Hydatid cysts: Liver
Echinococcus multilocularis-Pathogenesis and Lesions
Usually non-pathogenic.
In IH, alveolar or multilocular cyst grows large and can cause pressure necrosis of the liver and surrounding tissues. Alverolar hydatid is slow growing and eventually fatal
Echinococcus multilocularis-Clinical Signs
None in DH.
Invasive growth in humans/IH can be fatal
Echinococcus multilocularis-Diagnosis
Eggs in fecal flotation.
Eggs from Adhesive/Scotch tape method
Morphologically indistinguishable from Taenia eggs
Echinococcus multilocularis-Treatment and Prevention
Anthelmintic treatment, removal of stray dogs, prohibition against feeding uncooked offal
Taenia crassiceps-Hosts
DH: Foxes, dogs
IH: Small rodents
*Zoonosis-Abdominal cavity and the eye
Taenia crassiceps-Identification
Adult: scolex with 4 suckers up to 2 m long, rectangular segments with unilateral genital pores
Cysticerci: in abdominal cavity of IH, asexual budding
Eggs: brown color, radial striations in the shell, 6 embryonic hooks, indistinguishable from Echinococcus spp.
Taenia crassiceps-Life Cycle
Indirect. PPP 6-9 wks.
Taeniid segments shed from DH in feces→segments release eggs in environ.→eggs develop to oncospheres→oncosphere ingested by IH→enter to small intestine and go to abdominal cavity w/in IH→develops to second-stage larva (cysticercus)→buds into multiple cysticerci→DH ingests IH→develop into adult in small intestine
Taenia crassiceps-Site of Infection
Small intestine
Taenia crassiceps-Pathogenesis and Lesions
Zoonosis→in humans it can infect the eye and cause blindness
Taenia crassiceps-Clinical Signs
Usually asymptomatic
Taenia crassiceps-Diagnosis
Eggs in fecal flotation
Echinococcus and Taenia eggs are indistinguishable
Taenia crassiceps-Treatment and Prevention
Cestocidal drugs
Prevent eating offal
Taenia pisiformis-Hosts
DH: Dogs
IH: Rabbits
Taenia pisiformis-Identification
Adults are several meters
Taenia pisiformis-Life Cycle
Indirect. PPP = 56 days
Taeniid segments shed from DH→segments release eggs into environ.→develop into oncospheres→oncosphere ingested by IH→enters small intestine and migrates to liver and peritoneum in IH→develops into second-stage larva (cysticerus)→DH ingests cysticercus→develops into adult in small intestine of DH
Taenia pisiformis-Site of Infection
Adults: Small intestine of DH
Cysticerci: Liver and peritoneum of IH
Taenia pisiformis-Pathogenesis and Lesions
Non-pathogenic
Taenia pisiformis-Clinical Signs
Asymptomatic
Taenia pisiformis-Diagnosis
Eggs on fecal flotation
Taenia pisiformis-Treatment and Prevention
Cestocidal drugs
Prevent eating offal
Taenia taeniaeformis-Hosts
DH: Cats
IH: Rodents, humans
*Zoonosis
Taenia taeniaeformis-Identification
Adults: 60cm
Eggs: 25-40 um
Taenia taeniaeformis-Life Cycle
Indirect. PPP = 6 wk.
Taeniid segments shed from DH→segments release eggs into environ.→develop into oncospheres→oncosphere ingested by IH→enters small intestine and migrates to liver→develop into second-stage larva (strobilocercus)→DH ingests strobilocercus→develop into adult in small intestine of DH
Taenia taeniaeformis-Site of Infection
Adults: Small intestine in DH
Strobilocercus: Liver of IH
Taenia taeniaeformis-Pathogenesis and Lesion
Non-pathogenic
Taenia taeniaeformis-Clinical Signs
Asymptomatic
Taenia taeniaeformis-Diagnosis
Eggs on fecal flotation
Taenia taeniaeformis-Treatment and Prevention
Cestocidal drugs
Prevent eating offal
Diphyllobothrium latum-Common Name
Broad Fish Tapeworm
Diphyllobothrium latum-Hosts
DH: Dogs, cats, pigs, humans
IH: Copepod crustacean, Freshwater fish
*Zoonosis
Diphyllobothrium latum-Identification
Adults: 12m long, scolex without suckers, 2 slot-like grooves called bothria for attachment, square segments shed in groups
Eggs: Operculate, light brown, 60 um
Diphyllobothrium latum-Diagnosis
Fecal sedimentation
Egg can be confused with Fasciola hepatica (130 um) but are half the size
Spirometra spp.-Common Name
Zipperworm
Causes Sparganosis in humans
Spirometra spp.-Hosts
DH: Dogs, cats
IH: Crustaceans (host procercoid), Water snakes, frogs, rodents, birds (host plerocercoids)
*Zoonosis
Spirometra spp.-Identification
Adults: 2 m in length, scolex without suckers, but with 2 bothria, segments shed in groups
Plerocercoids: 4-10 cm in length
Eggs: Operculate, light brown, 60 um
Spirometra spp.-Diagnosis
Fecal sedimentation
Egg can be confused with Fasciola hepatica (130 um) but are half the size
