Cestodes and Metacestodes Flashcards
Dipylidiasis
Dipylidium caninum
Dipylidium caninum - Common name
Double-pored tapeworm
Dipylidium caninum - Taxonomy
Class: Cestoidea
Order: Cyclophyllidea
Dipylidium caninum - Hosts and distribution
Dog, cat, fox
Cosmopolitan
Dipylidium caninum - Morphology
2 genital pores
Up to 50 cm/19” long
Eggs in egg packets
Dipylidium caninum - Life cycle
Egg packets released from host rectum
Eaten by flea larva and becomes a cysticercoid
Host eats infected flea
Adults develop in small intestine
Dipylidium caninum - PPP
2-3 weeks
Dipylidium caninum - Pathology
Blockage in heavy infections
Dipylidium caninum - Clinical signs
Minimal
Emaciation in severe infections
Abdominal discomfort
Dipylidium caninum - Diagnosis
Gravid segments around anus
Egg packets in fecal exam
Dipylidium caninum - Treatment
Praziquantel
Epsiprantel
MUST TREAT FOR FLEAS TOO
Dipylidium caninum - Public health
Rarely children will become infected
Taeniasis
Taenia pisiformis
Taenia taeniaeformis
Taenia sp. - Common name
Taenias
Taenia sp. - Hosts and distribution
Dogs and cats
Taenia sp. - Taxonomy
Class: Cestoidea
Family: Taeniidae
Taenia sp. - Morphology
Big
Scole with arm rostellum
Single marginal genital pores
Taenia pisiformis - Metacestode, IH, and Location
Metacestode: Cysticercus
IH: Rabbit
Location: Peritoneal cavity
Taenia taeniaeformis - Metacestode, IH, and Location
Metacestode: Strobilocercus
IH: Rodents
Location: Liver
Taenia sp. - Life cycle
Gravid segments in feces Eggs ingested by IH Hexacanth embryo develops into metacestode Host eats IH with metacestode Tapes mature in small intestine
Taenia sp. - PPP
2-3 months
Taenia sp. - Pathology
Usually none unless heavy infection
Metacestode in IH can cause physiological or neurological damage
Taenia sp. - Clinical signs
No definite signs
Taenia sp. - Diagnosis
Segments in feces
Eggs in feces
Taenia sp. - Treatment
Fenbendazole
Praziquantel
Epsiprantel
Taenia sp. - Control
- Regular anthelmintic treatment of dogs and cats
2. Don’t permit pets to eat rabbits or rodents
Taenia sp. - Public health
Only Echinococcus granulosus (alveolar hydatid disease and cystic hydatid disease) and E. multiocularis
Kills people
Echinococcus sp. - Morphology
Typical taenia type egg
Adults 1-6 mm
Cestodiasis
Mesocestoides spp.
Mesocestoides spp. - Host and distribution
Canids, cats, raccoons, foxes
Western US
Mesocestoides spp. - Morphology
Scolex with 4 suckers but no hooks or rostellum
1 m in length
Mesocestoides spp. - Life cycle
1st IH: cysticercoid in oribatid mite or dung beetle
2nd IH: tetrathyridia in amphibians, reptiles, birds, and mammals
Mesocestoides spp. - Pathology
Intestinal infection non-pathogenic
Tetrathyridial infection in dogs and cats can cause severe peritonitis
Mesocestoides spp. - Clinical signs
Adults: Usually none
Peritoneal mesocestodiasis: Ascites, anorexia, weight loss, emesis, diarrhea, depression, fever
Mesocestoides spp. - Diagnosis
Adults: Motile segments in stool or eggs in fecal
PLC - Clinical signs and identification of tetrathyridia in abdominal effusion
Mesocestoides spp. - Treatment
Adult tapes: Prazi
PLC: Fenbendazole & peritoneal lavage
Mesocestoides spp. - Public health
Ingetions of tetrathyridia in undercooked meat
Pseudophyllidea
Diphyllobothrium latum
Spirometra mansonoidea
Diphyllobothrium latum - Common name
Broad fish tapeworm
Spirometra mansonoideas - Common name
Zipper tapeworm
Pseudophyllidea - Taxonomy
Class: Cestoidea
Order: Pseudophyllidea
Family: Diphyllobothridae
Pseudophyllidea - Morphology
Large worms
Scolex elongated with 2 bothria (no suckers or hooks)
Operculated eggs
Diphyllobothrium latum - Life cycle
Operculated eggs escape intestine
Coracidium hatch in water and eaten by copepod
Develops into a proceroid
Copepod eaten by a fish, becomes plerocercoid in fish muscles
Host eats fish with plerocercoid
Spirometra mansonoides - Life cycle
Operculated eggs escape intestine
Coracidium hatch in water and eaten by copepod
Develops into a proceroid
Copepod eaten by a frog, water snake, or rodent and becomes plerocercoid in SQ tissue
Host eats fish with plerocercoid
Pseudophyllidea - PPP
2-6 weeks
Pseudophyllidea - Pathology
Not in dogs and cats
Pseudophyllidea - Clinical signs
None
Pseudophyllidea - Diagnosis
Fecal sedimentation
Recovery of gravid segments in feces
Diphyllobothrium latum - Treatment
None approved
Praziquantel
Spirometra mansonoides - Treatment
None approved
Praziquantel
Diphyllobothrium latum - Public health
Humans infected as a result of eating undercooked fish
Vitamin B12 deficiency, diarrhea, constipation, abdominal pain, fatigue
Spirometra mansonoides - Public health
Humans can be paratenic or second IH
Acquired by drinking contaminated water or eating undercooked fish
Cause sparganosis
Neurological symptoms