Chapter 13(parasites) Flashcards
trophozoite
protozoan parasite stage that actively feeds and multiples
cyst
protozoan parasite stage with a protective membrane or thickened wall
fresh wet mount preparations
the best way to locate and identify protozoan parasites
velvet disease
in fish common protozoan infections, caused by Piscinoodinium, ectoparasite
white spot
in fish, caused by Ichthyophthirius multifilis, ectoparasite
pseudopods
are an extension of their body that help the amoeba to move and engulf prey
entamoeba histolytica
Causes amoebic dysentery, ulcers and diarrhea, can spread other organs such as liver, where they form abscesses
infects rats, dogs, cats(rarely), NHP, and humans
Apes, New World primates, and humans are most severely affected
flagellates that are the only genera that contain species known to be pathogenic to lab animals
hexamita(Spironucleus), trichomonas, and giardia
trypanosoma brucei
found in NHP and can infect humans, causing a disease called sleeping sickness
trypanosomes, are found in peripheral blood and lymphatic fluid rather than the GI tract
balantidium coli
cilia pathogenic parasite
can infect humans, apes, some monkeys, and swine
causes diarrhea
diagnosis is made by microscopic fecal examination
apicomplexan organisms
intracellular parasites that form spores as a means of transmission from one host to another
apicomplexan organisms examples:
coccida, crytosporidium muris, eimeria stiedae, and toxoplasma gondii
crytosporium muris is found where in which animals
GI tract of rodents
what are helminths
multicellular, worm-like animals which have differentiated tissues and organs
what are the groups helminths are classified in
Trematodes (flukes)
Cestodes (flatworms)
Nematodes (roundworms)
Acanthocephalids (thorny-headed worms)
Hirudineans (leeches)
what is the life cycle of a fluke
- eggs hatch in water and mature in an AQUATIC SNAIL
- larval fluke hatch from snail and encyst on aquatic plants where they are then eaten by animals or people
- once ingested, the cysts hatch and burrow through the intestinal wall into the peritoneum and migrate toward the liver
- in the liver, the larva hatch into mature flukes and begin producing more eggs
how do you diagnosis flukes in an animal
microscopically by finding eggs in the urine or feces or by finding adults on necropsy or in tissue sections
what kind of parasite is a tapeworm
cestodes
where and how are tapeworms found in the body of hosts
in the intestinal tract
they attach to the intestinal walls with a ring of hooks called a SCOLEX
what are
the chain of segments of a tapeworm called
proglottids
what is the common tapeworm species found in dogs and cats?
Dipylidium caninum
what are hydatid cysts
fluid-like cyst containing larvae in the host’s liver and other organs, usually when the tapeworm infests an unnatural host
what are nematodes called?
roundworms
what are the classes of roundsworms
nonsegmented, cylindrical, and elongate worms
what do YOU need to know about whipworms?
Trichuris spp.
they have bodies with a whip(hence the name)
can infect most lab species
adults inhabit the cecum or colon
large numbers can cause diarrhea
swine parasite: TRICHINELLA SPIRALIS it does not lay eggs, it puts larvae in host intestines they pass through the bloodstream to the muscle and grow there to encyst and infect
Need to know about Ascarids
most commonly seen helminths in lab animals
3 types of these: toxacara canis, toxcara cati, and toxascaris leonia
Toxocara canis: canine roundworm infect by dogs eating them of by larvae crossing the placenta and infecting fetuses
need to know about pinworms
found in cecum and colon of NHP, rodents, and horses
fecal-oral without intermediate host
SYPHACIA SPP. AND ASPICULARIS TETRAPTERA are common in mice and rats
need to know about hookworms
roundworm
teeth-like structures
enter through skin or fecal-roal or through placenta or milk
ANCYLOSTOMA CANINUM: in dogs and cats
OESOPHAGOSTOMUM spp: in old world monkeys and zoonotic to humans
STRONGLYIS (strongyles): horse , fecal oral
need to know about filaria
elongated, slender delicate ROUNDWORM
female produces microscopic larvae (MICROFILARIAE) not eggs
mosquitos and other blood-sucking insects are vectors
DIROFILARIA IMMITIS heartworm of dogs found in heart and pulmonary arteries
need to know about Acanthocephalids
thorny-headed worms
Acanthocephala require and intermediate host
latch to intestinal mucosa
MONILIFORMIS MONILIFORMIS: rats
PROSETHENORCHIS ELEGANS: New world monkeys
detected through fecal sedimentation
need to know about Annelida
leeches of the class Hirudinea
infest through the nose, mouth, and parynx or attaching to the skin
Dinobdella ferox observed hanging from nasal passages of rhesus monkeys and give them nose bleeds
large number of leeches can cause anemia, asphyxiation, and death
can be removed with gentle traction with forceps
