Internal Parasites Flashcards
Direct Life Cycle
No intermediate host needed for developement to infective stage
Indirect Life Cycle
Intermediate host needed for developement to infective stage
Intermediate Host
Host that supports the immature or non-reproductive form of a parasite
Paratenic / Dead-end Host
Host where parasite has no further developement
Definitive Host
- Final host
- Hosts the sexually mature adults
Prepatent Period
Period between parasitic infection and time where parasite can be detected in blood/feces
Roundworms
- Ascarids
- “Toxocara”
- Located in small intestines
Roundworm Transmission
- Egg ingestion
- Mom to babies via embryo transfer or nursing
Roundworm Symptoms
Puppies / Kittens
* vomiting
* diarrhea
* enlarged abdomen
* dull haircoat
Adults
* no clinical signs or diarrhea
Rare
* intestinal blockage
* anemia
Roundworm
Roundworm Treatment
- Fenbendazole / Panacur
- Pyrantel
Roundworm Zoonosis
Humans are paratenic hosts
* visceral larval migrans (liver / lungs)
* ocular larval migrans (eye)
Roundworm Prevention
- Remove feces and clean kennels
- Proper hygiene
- Deworming mom prior to breeding
Hookworms
- Strongyloidea
- “Ancylostoma”
- Located in small intestines
Hookworm
Hookworm Transmission
- Ingestion of larva
- Larva penetration into skin
- Mom to babies via embryo transfer or nursing
Hookworm Symptoms
- Anemia
- Diarrhea
- Underweight
- Distended abdomen
- Poor hair coat
- Inappetence
- Dermatitis from penetration into skin
Hookworm Treatment
- Fenbendazole / Panacur
- Pyrantel
Hookworm Zoonosis
Humans are paratenic hosts
* cutaneous larval migrans (skin)
Hookworm Prevention
- Remove feces and clean kennels
- Proper hygiene (don’t walk barefoot)
- Deworm mom prior to breeding
Intestinal Threadworms
- Strongyloides spp.
- Located in intestines
- “club-shaped” larva
Threadworm
Whipworms
- Trichuroidea
- “Trichuris”
- Found in cecum and colon
Whipworm
Whipworm Transmission
Ingestion of eggs from contaminated environment
Whipworm Symptoms
- Can be asymptomatic
- Colitis / Diarrhea
- Weight loss
- Anemia
Whipworm Prevention
- Remove feces and clean kennels
- Avoid contaminated areas - can survive in soil for months-years
Stomach Worm
- Spiruroidea
- “Physaloptera spp.”
- Found in stomach lumen and small intestines
Types of Nematodes
- Roundworms
- Hookworms
- Intestinal Threadworms
- Whipworms
- Stomach Worms
- Heartworms
Types of Trematodes
- Intestinal fluke
- Lung fluke
Intestinal Fluke
- Alaria spp.
- Non-pathogenic
Lung Fluke
- Paragonimus spp.
- Found within the lungs
- Transmitted by eating snails or crayfish
Cestode Body Parts
Scolex
* head
* 2-4 muscular suckers +/- hooks
Rostellum
* snout
* on top of head
Strobila
* body
Proglottids
* segments of body that pass into environment
* make up different stages of maturity (immature by neck)
Cestode Types
Tapeworms
* Dipylidium
* Taenia
Dipylidium caninum
- Transmitted: flea ingestion
- Symptoms: asymptomatic
- Treatment: Praziquantel / Drontal
Tapeworm
Dipylidium caninum
Taenia spp.
- Transmitted: infected rabbit/hare ingestion
- Treatment: Praziquantel / Drontal or Fenbendazole / Panacur
Tapeworm
Taenia spp.
Types of Pseudotapeworms
- Spirometra spp.
- Diphyllobothrium spp.
Spirometra spp.
- “Zipper” Tapeworms
- Transmission: ingestion of amphibian or
mammalian paratenic hosts
“Zipper” Tapeworm
Broad Fish Tapeworm
- Diphyllobothrium spp.
- Transmission: ingestion of fish
Broad Fish Tapeworm
Define
Protozoa
- Single-celled organism
- One or more membrane-bound nuclei
- Contain DNA and specialized cytoplasmic organelles
Protozoa Organelles
- Flagella - long, whiplike structures
- Cilia – short flagella arranged in rows or tufts
- Pseudopodia – temporary extensions and retractions of the body wall
- Undulatory ridges – small, snakelike waves that form in the cell membrane and move posteriorly
Protozoa Life Stages
- Trophozoite
- Cyst Stage
Trophozoite
Protozoa Life Stage
- Vegetative form
- Capable of eating, moving, and reproduction
- Too fragile to survive transfer to new host
- Not infectious
Cyst Stage
Protozoa Life Stage
- Metabolic functions suspended
- Cyst wall prevents drying out
- Transmitted to new host in this form
Giardia
- Flagellated protozoa
- Symptoms: asymptomatic to diarrhea
- Transmission: ingestion of cysts passed in feces
- Treatment: Fenbendazole / Panacur and Metronidazole
Giardia Trophozoite
Giardia Cyst
Giardia Diagnosis
- Cyst - fecal float with zinc sulfate
- Trophozoite - direct smear
- Fecal immunodiagnostics
Giardia Prevention
- Provide clean water
- Bathe to remove fecal debris
Trypanosoma cruzi
- Chagas Disease
- Transmitted by the “kissing bug” - defecates by feeding spot on host
- Zoonotic - contact with contaminated blood
Trypanosoma cruzi
Leishmania spp
- Transmitted: sand fleas
- Zoonosis: dogs act as reservoir for human disease
Leishmania spp
Coccidia
- Isospora
- Found in small intestines
- Not zoonotic (species specific)
Coccidia Symptoms
Puppies / Kittens
* diarrhea
Adults
* asymptomatic
Coccidia Transmission
- Ingestion of sporulated oocyst from soil
- Ingestion of mammalian paratenic host
Coccidia
Coccidia Treatment
- Albon
- Ponazuril
Toxoplasma gondii
Transmission
* eating undercooked meat
* ingestion of oocytes from cat feces (cleaning litter box or gardening)
Zoonotic
* generally not an issue for healthy people
* fetuses of pregnant women can be affected
Cryptosporidium spp.
- Transmission - ingestion of eggs from feces (cows)
- Zoonotic - bad diarrhea
