Intro to Parasitology

Question 1

What kind of parasite is Ancylostoma caninum?

Answer 1

Helminth (nematode) - Hookworm

Question 2

Pathogenesis of Ancylostoma caninum (hookworm)

Answer 2

Attaches to and ingests mucosal lining of intestines.

Ingests blood.

Question 3

Signs of Ancylostoma caninum infection

Answer 3

Anemia, lethargy, weight loss, weakness

Question 4

What is Isospora suis?

Answer 4

Coccidium (protozoan)

Question 5

What kind of parasite is Dirofilaria immitis?

Answer 5

Helminth (nematode) - Heartworm

Question 6

What are the 3 main classes of parasite that can cause disease in humans? (zoonoses)

Answer 6

Helminths
Ectoparasites
Protozoa

Question 7

Clinically relevant zoonoses (4)

Answer 7

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)

Question 8

Method of diagnosing parasites (SIS)

Answer 8

host Species
site of Infection
Size of parasite

Question 9

Parasites relevant to production (food animals)

Answer 9

Ostertagia ostertagi - parasitic nematode in cattle. Causes ostertagiosis.

Eimeria tenella - hemorrhagic cecal coccidiosis in young poultry

Question 10

Treatment and prevention of parasite

Answer 10

Parasiticides
Sustainable management of host
Management of environment
Life cycle to determine treatment and prevention

Question 11

What is the largest group of clinically relevant helminths?

Answer 11

Roundworms

Phylum: nemathelminthes
Class: nematoda

Question 12

Classification of flatworms

Answer 12

Phylum: Platyhelminthes
Class: cestoda (tapeworms)
Class: trematoda (flukes)

Question 13

Characteristics of Nematodes

Answer 13

Free-living OR parasitic
Elongate/cylindrical
Alimentary canal present
Usually separate sexes
Life cycle direct or indirect

Question 14

In the adult ascarid, which sex is larger in size?

Answer 14

Female

Question 15

Characteristics of Cestodes

Answer 15

Flat body
No alimentary canal (absorb through body s.a.)
Indirect life cycle
Characteristic larval stages

Question 16

What are the segments of the tapeworm’s body?

Answer 16

Proglottids - hermaphroditic!

Question 17

What is the tapeworm’s body called?

Answer 17

Strobila

Question 18

What is a scolex?

Answer 18

Hold fast organ of tapeworm. Mouth and head piece.

Question 19

Characteristics of trematodes

Answer 19

Dorso-ventrally flattened
Oral and ventral suckers
Alimentary canal present
Indirect life cycle - molluscan IH
Usually genitally independent

Question 20

Leaf-like parasite

Answer 20

Flukes (trematodes)

Question 21

2 types of relevant parasitic arthropods

Answer 21

Insects

Arachnids

Question 22

Clinically relevant insect groups (4)

Answer 22

Flies (Diptera)
Fleas (Siphonaptera)
Lice (Phthiraptera)
Hemiptera

Question 23

Clinically relevant arachnids

Answer 23

Ticks

Mites

Question 24

Identification of an insect (physical features)

Answer 24

3 pairs of legs (adults)

Head, thorax, and abdomen

Antennae

Question 25

Stomoxys calcitrans

Answer 25

Stable fly. Has piercing mouthparts.

Question 26

What does the stable fly, Stomoxys calcitrans, transmit?

Answer 26

Nematodes

Question 27

What kind of mouthparts does the house fly have?

Answer 27

Labellum (sucking). Differs from stable fly (piercing).

Question 28

Complications of flea (Siphonaptera) infestation

Answer 28

Anemia Blood borne disease tapeworm infection flea allergy dermatitis

Question 29

Lice (Phthiraptera) classification by mouthparts

Answer 29

Sucking (narrow mouth) - Linognathus setosus (dog sucking louse) Chewing (large, robust mandible)- Trichodectes canis (dog chewing louse)

Question 30

Identification of ticks and mites

Answer 30

4 pairs of legs (nymphs and adults) *larvae have 3 pairs of legs Cepahlo-thorax and abdomen Palps. No antennae

Question 31

What feature of the tick allows for expansion of the abdomen after a meal, and can also be used to identify a species?

Answer 31

Scutum

Question 32

Clinically relevant mites

Answer 32

Sarcoptes scabiei - sarcoptic mange Cheyletiella blakei - walking dandruff Demodex canis - demodectic mange

Question 33

What do Demodex species typically look like?

Answer 33

Cigar-like with short legs

Question 34

Characteristics of protozoa

Answer 34

Unicellular, eukaryotic animals (true nucleus) Classified based on locomotion

Question 35

Methods of protozoa locomotion (4)

Answer 35

Pseudopodia Flagella Gliding movements Cillia

Question 36

Clinically relevant protozoa

Answer 36

Giardia Coccidia Babesia

Question 37

Identification of Giardia trophozoites

Answer 37

``` Bilaterally symmetrical 2 nuclei 8 flagella 2 rod-like, median bodies concave, adhesive disk gives clown face ```

Question 38

I. canis and I. ohioensis are types of

Answer 38

Coccidia

Question 39

Babesia canis

Answer 39

Found within erythrocytes, can cause anemia. Usually found in pairs. Transmission is via brown dog tick.

Question 40

Questions clients will ask when their pet is diagnosed with a parasite:

Answer 40

``` 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? ```