Veterinary Medical Applications
Lesson Title: Parasitology
This is a continuation of the principles of diseases unit
TEKS Addressed in Lesson:
130.6. (c)(8) all
130.6. (c)(9) all
Lesson Objectives:
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Identify parasite at larval and adult stages
List and describe the symptoms of internal or external parasites
Recall methods of control/prevention
Explain the different stages of the parasite life cycle and the effects on the animal body
Understand and demonstrate methods of testing for and treating parasitic infections
Key Terms/Vocabulary
Parasite- an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's
expense
Endoparasite- a parasite, such as a tapeworm, that lives inside its host
Ectoparasite- a parasite, such as a flea, that lives on the outside of its host
Direct Transmission- transmission mechanism in which the infectious agent is transferred directly into the body via
touching or biting or kissing or sexual intercourse or by droplets entering the eye or nose or mouth
Indirect Transmission- a transmission mechanism in which the infectious agent is transferred to the person by a fomite
of vector
Larva- the active immature form of an insect, esp. one that differs greatly from the adult and forms the stage between
egg and pupa, e.g., a caterpillar or grub
Vector- an organism, typically a biting insect or tick, that transmits a disease or parasite from one animal or plant to
another
Host- an animal or plant on or in which a parasite or commensal organism lives
Interest Approach/Anticipatory Set
-define parasitology (discuss this as a specialization)
-discuss the zoonotic diseases and identify parasitic as one of 4 types
-Discuss symbiosis and facts related to parasites that do not cause damage
Teaching Plan and Strategy Presentation of New Material
Teacher PowerPoint/Student notes going over the types of parasites, their lifecycle and explanation of effects and
testing for, treating and prevention.
PowerPoint should cover the following for each parasite: (roundworms, tapeworms, hookworm, whipworms, protozoa,
heartworms, fleas, ticks, lice)
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-damages
-signs and symptoms
-lifecycle
-treatment and prevention
-threat to humans
Activity/Application/Student Engagement/Laboratory
Lab Activities
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Fecal Smear-have students perform a fecal flotation to test several stool samples for infestation
Using a microscope- students should practice adjusting a microscope
Evaluation/Summary
Teacher Check for understanding
Fecal Flotation Lab
Microscope Lab
Parasitology Test
Parasitology Test
____ 1. microfilaria
a. a microscopic single-celled animal
____ 2. proglottid
____ 3. vector
b. animal ingest feces or vomit infected with
parasites
c. ascarid
____ 4. protozoa
d. animal ingests paratenic host
____ 5. paratenic host
e. the larval state of the heartworm
____ 6. direct transmission
f. host in which a parasite goes through the
larval stage of development
g. head of the tapeworm
___ 7. direct transmission
___ 8. Roundworm
___ 10. intermediate host
h. the segment of the tapeworm containing the
male and female reproductive organs
i. host that helps spread a parasite without the
parasite developing within it
j. transmammary
___ 11. indirect transmission
k. Cestode
___ 12. Scolex
l. an animal, usually a tick or insect, that
transmits the disease causing organisms
___ 9. tapeworm
List the area in the body where the following parasites reside.
13. tapeworm14. hookworm15. mite16. whipworm17. protozoa-
18. Explain, in detail, how one might check/test for parasite infestation.
19. Explain how to do a “simple test” for flea infestation.
20. The condition defined as lack of blood is known as ________________________.
21. Define: microfilaria-
22. What is the head of the tapeworm called?
23. What the “rice looking” segments of a tapeworm called?
24. Discuss the difference between direct/indirect transmission and give an example of each.
25. List 3 of the damages endoparasites may cause?
26.List 2 of the damages ectoparasites may cause?
27.List at least 3 clinical signs associated with endoparasites.
28.List at least 3 clinical signs associated with ectoparasites.
29.What is the most common internal parasite in kittens and puppies?
30. Where in the body do hookworms travel and stay?
31. Explain the damage of heartworms?
32. What is D. immitis?
33. Which worm attaches itself to the intestinal lining?
34. How is heartworm contracted?
35. Describe two methods of testing/diagnosing parasites.
37. T or F Lice infestation takes place in the warmer seasons.
38. An animal that has mite infestation is said to have ___________________________.
39. Describe the general life cycle of most external parasites. (you may draw this)
40. The two types of lice are:
41. Of the external parasites, which are not host specific?
42. T or F All internal parasites can be passed on to humans.
43. T or F All internal parasites are deadly if not treated.
45. Which parasite causes scabies in humans?
References/Additional Materials/Extended Learning Opportunities/Enrichment
Merck Veterinary Manual
Introduction to Veterinary Science, McGraw/Hill
College and Career Readiness Standards:
Science
I. B. 1
VI. A-G