Lecture 1: Introduction to Veterinary Parasitology

Question 1

How do taxonomists classify organisms into groups

Answer 1

Based on characteristics/characters that group members share in common

Characters: morphological, physiological, molecular, behavioral

Question 2

What is the scutum

Answer 2

Dorsal plate (back)

Question 3

How do you differentiate between ornate and inornate

Answer 3

Coloration/markings are present in ornate but not in inomate

Question 4

Classifying the following as ornate, inornate and then long vs short palps

Answer 4

Both: ornate
Left: long palps
Right: short palps

Question 5

Identify the following as ornate or inornate and then long vs short palps

Answer 5

Both: inornate
Left: long palps
Right: short palps

Question 6

What does symbiosis mean

Answer 6

Living together

Question 7

What is a mutualism symbiosis

Answer 7

Both the Protozoa and host benefit

Question 8

Provide an example of mutualism

Answer 8

Gut flagellate and termite

Question 9

What is a commensal symbiosis

Answer 9

Protozoa benefits and the host is neither harmed or helped

Question 10

Provide an example of commensalism

Answer 10

Entamoeba coli and monkey

Question 11

What is the parasitic symbiosis

Answer 11

Protozoan benefits and host is harmed

Question 12

Provide an example of parasitism

Answer 12

E. Histolytica and monkey

Question 13

How do we differentiate commensal vs parasitic amoebae histologically

Answer 13

Commensal amoebae mature cyst contain 8 nuclei (octonucleate)

Parasitic amoebae mature cyst contain 4 nuclei (quadrinucleate)

Question 14

What are the three traditional groups of parasites

Answer 14

1. Parasitic Protozoa
2. Helminths/ parasitic worms
3. Parasitic arthropods

Question 15

Name 3 common parasitic worms/helminths

Answer 15

1. Nematodes
2. Tapeworms
3. Flukes

Question 16

Which type of parasites infest the skin, hair, and feathers

Answer 16

Ectoparasites

Question 17

Provide some examples of ectoparasites

Answer 17

Ticks and lice

Question 18

What type of parasites infect the internal organs and tissues

Answer 18

Endoparasites

Question 19

Provide some examples of endoparasites

Answer 19

Tapeworms and hookworms

Question 20

Equine blood worm (strongylus vulgaris) exhibit a change in predilection site. Where are they located as fourth stage larvae vs as adult worms

Answer 20

Fourth stage larvae: in wall of cranial mesenteric artery

Adult worms: attach to mucosa of equine colon and cecum

Question 21

What are some adaptations parasites have for feeding

Answer 21

Piercing/sucking mouthparts
Hooks, suckers, spines and other holdfast organs

Question 22

Parasites release ___ and ____ during hematophagy during feeding

Answer 22

Anticoagulants and vasodilators

Question 23

Tapeworms and hook worms don’t have mouths or guts so how do they absorb nutrients

Answer 23

Across parasites outer surface

Question 24

What mechanisms do parasites use to deter hosts

Answer 24

Acid and enzyme resistant eggs, cysts, larval stages, avoid immune response, counter immune response

Question 25

How do parasites avoid immune response

Answer 25

Antigenic variation, intracellular habitat, encystment within the host

Question 26

How do parasites counter immune response

Answer 26

Immunomodulation, kill immune cells, cleave antibodies

Question 27

What adaptations do parasites have to ensure successful reproduction and transmission

Answer 27

High reproductive potential, environmentally resistant eggs and cysts, host seeking behavior, altering host behavior

Question 28

What are some methods of ensuring high reproductive potential in parasites

Answer 28

Asexual reproduction, hermaphroditism, high output of eggs, cysts

Question 29

What are two examples of host seeking behavior

Answer 29

1. Questing tick 2. Canine hookworm larvae remain close to surface level in soil to increase chances of encountering a host

Question 30

Provide a common example of a parasite that alters host behavior

Answer 30

Taenia multiceps (tapeworm) migrates to brain in sheep resulting in gid (ataxia/circling) making sheep easy prey for canids and facilitating transmission

Question 31

What are some examples of parasites modes of transmission

Answer 31

1. Ingestion of eggs, cysts, larvae in food/water 2. Direct contact between hosts 3. Transplacental; transmammary 4. Penetration of skin or mucous membranes 5. Vector transmission

Question 32

Zoonosis

Answer 32

Infectious disease of non-human animals transmitted to humans

Question 33

How can you determine male vs female in ticks

Answer 33

Look at scutum: Male have scutum that covers majority of dorsal aspect Female: covers only a piece of dorsal aspect

Question 34

What type of tick is this and which is male and which is female

Answer 34

Rhipicephalus sanguineus Left: male Right: female

Question 35

What type of tick is this and which is male vs female

Answer 35

Amblyomma Americanium Left: male Right: female