Intro to Parasitology Flashcards
What kind of parasite is Ancylostoma caninum?
Helminth (nematode) - Hookworm
Pathogenesis of Ancylostoma caninum (hookworm)
Attaches to and ingests mucosal lining of intestines.
Ingests blood.
Signs of Ancylostoma caninum infection
Anemia, lethargy, weight loss, weakness
What is Isospora suis?
Coccidium (protozoan)
What kind of parasite is Dirofilaria immitis?
Helminth (nematode) - Heartworm
What are the 3 main classes of parasite that can cause disease in humans? (zoonoses)
Helminths
Ectoparasites
Protozoa
Clinically relevant zoonoses (4)
Toxocara canis - roundworm (visceral or ocular)
Ancylostoma braziliense - hookworm (cutaneous)
Toxoplasma gondii - protozoan
Taenis solium - pork tapeworm (cestode) (adult tapeworms in small intestine; larva can travel to brain and create cysts)
Method of diagnosing parasites (SIS)
host Species
site of Infection
Size of parasite
Parasites relevant to production (food animals)
Ostertagia ostertagi - parasitic nematode in cattle. Causes ostertagiosis.
Eimeria tenella - hemorrhagic cecal coccidiosis in young poultry
Treatment and prevention of parasite
Parasiticides
Sustainable management of host
Management of environment
Life cycle to determine treatment and prevention
What is the largest group of clinically relevant helminths?
Roundworms
Phylum: nemathelminthes
Class: nematoda
Classification of flatworms
Phylum: Platyhelminthes
Class: cestoda (tapeworms)
Class: trematoda (flukes)
Characteristics of Nematodes
Free-living OR parasitic Elongate/cylindrical Alimentary canal present Usually separate sexes Life cycle direct or indirect
In the adult ascarid, which sex is larger in size?
Female
Characteristics of Cestodes
Flat body
No alimentary canal (absorb through body s.a.)
Indirect life cycle
Characteristic larval stages
What are the segments of the tapeworm’s body?
Proglottids - hermaphroditic!
What is the tapeworm’s body called?
Strobila
What is a scolex?
Hold fast organ of tapeworm. Mouth and head piece.
Characteristics of trematodes
Dorso-ventrally flattened Oral and ventral suckers Alimentary canal present Indirect life cycle - molluscan IH Usually genitally independent
Leaf-like parasite
Flukes (trematodes)
2 types of relevant parasitic arthropods
Insects
Arachnids
Clinically relevant insect groups (4)
Flies (Diptera)
Fleas (Siphonaptera)
Lice (Phthiraptera)
Hemiptera
Clinically relevant arachnids
Ticks
Mites
Identification of an insect (physical features)
3 pairs of legs (adults)
Head, thorax, and abdomen
Antennae
Stomoxys calcitrans
Stable fly. Has piercing mouthparts.
What does the stable fly, Stomoxys calcitrans, transmit?
Nematodes
What kind of mouthparts does the house fly have?
Labellum (sucking). Differs from stable fly (piercing).
Complications of flea (Siphonaptera) infestation
Anemia
Blood borne disease
tapeworm infection
flea allergy dermatitis
Lice (Phthiraptera) classification by mouthparts
Sucking (narrow mouth) - Linognathus setosus (dog sucking louse)
Chewing (large, robust mandible)- Trichodectes canis (dog chewing louse)
Identification of ticks and mites
4 pairs of legs (nymphs and adults)
*larvae have 3 pairs of legs
Cepahlo-thorax and abdomen
Palps. No antennae
What feature of the tick allows for expansion of the abdomen after a meal, and can also be used to identify a species?
Scutum
Clinically relevant mites
Sarcoptes scabiei - sarcoptic mange
Cheyletiella blakei - walking dandruff
Demodex canis - demodectic mange
What do Demodex species typically look like?
Cigar-like with short legs
Characteristics of protozoa
Unicellular, eukaryotic animals (true nucleus)
Classified based on locomotion
Methods of protozoa locomotion (4)
Pseudopodia
Flagella
Gliding movements
Cillia
Clinically relevant protozoa
Giardia
Coccidia
Babesia
Identification of Giardia trophozoites
Bilaterally symmetrical 2 nuclei 8 flagella 2 rod-like, median bodies concave, adhesive disk gives clown face
I. canis and I. ohioensis are types of
Coccidia
Babesia canis
Found within erythrocytes, can cause anemia.
Usually found in pairs.
Transmission is via brown dog tick.
Questions clients will ask when their pet is diagnosed with a parasite:
What is it? How can you tell Gizmo has it? Where did it come from? What harm does it cause? Can you get rid of it? Will it infect people?
