Portland Community College | Portland, Oregon

The purpose of this course is to introduce the veterinary technology student to the important parasitic organisms in veterinary medicine. It is intended for first-year veterinary technology students and is a graduation requirement for the Associates of Applied Sciences in Veterinary Technology.  Credits in this course are not transferable to a four-year school towards a baccalaureate degree.   

Upon completion of the course students should be able to:

• Recognize and use basic terminology describing parasites, their hosts and their life cycles.
• Identify and describe the physical characteristics and pathogenesis of parasitic organisms of the following phyla: Arthropoda, Nematoda, Acanthocephala, Cestoda, Trematoda, and Protozoa. 
• Perform laboratory procedures in the collection, processing, and evaluation of fecal, urine, blood, hair, skin, or tissue samples used for parasite identification.
• Differentiate relevant clinical parasites from non-clinical artifacts within diagnostic samples.

This is a three credit-hour course that meets for 1 lecture hour and 4 lecture-lab hours per week.  The didactic portion of the course will include taxonomy, life cycles, modes of transmission, geographic distribution, disease entities associated with each parasite and description of the identifying characteristics or each organism studied.  The lab portion of the course will include prepared slides, preserved specimens, staining techniques, collection methods, concentration techniques, and identification of both cysts and eggs.

Outcomes will be assessed by the following means:

• Grading will be based upon student understanding of the course content as demonstrated by periodic examinations, homework assignments, quizzes, a comprehensive final exam, performance of laboratory tasks, and attendance. To be eligible for a passing grade, the student must have attended a minimum of 80 percent of classes.
• Graduate performance on the “Laboratory Procedures" sub-section of the Veterinary Technicians National Examination.
• These outcomes will be routinely assessed and used to drive relevant changes in the curriculum.

Content labeled with an asterisk indicates content required by our accreditor.  Content that is also italicized indicates tasks that the student must be able to perform since they are listed as “essential tasks” by the Accreditation Policies and Procedures of the American Veterinary Medical Association's Committee on Veterinary Technician Education and Activities.

1.0  INTRODUCTION

INSTRUCTIONAL GOAL:

The goal is to introduce students to the field of parasitology and basic terms used for describing parasites and their life cycles.

OBJECTIVES:

            1.1   Define and apply the following terms:

a.    Symbiont

b.    Commensal

c.    Mutualism

            d.    Parasitism

1.2   Differentiate and correctly apply the following terms:

a.    Ectoparasite parasite

b.    Endoparasite parasite

c.    Facultative parasite

d.    Incidental parasite

e.    Obligatory parasite

f.    Intermittent or periodic parasite

g.    Permanent parasite

1.3   Identify and/or define the following types of hosts:

a.    Definitive

b.    Intermediate

c.    Vector

d.    Reservoir

e.    Incidental

2.0  PHYLUM ARTHROPODA

INSTRUCTIONAL GOAL:

The goal is to characterize the phylum Arthropoda and its two major classes containing parasitic organisms.  Also, to be able to recognize and characterize the following organisms of common concern.

OBJECTIVES:

2.1   List three characteristics for the phylum Arthropoda and characterize the following classes:

a.    Arachnida – ticks and mites

b.    Insecta

     2.2   Compare the characteristics of ticks and mites.

     2.3   Identify (from images or whole specimens) different genera of ticks. Representative tick genera may include (but are not limited to):*

a.    Argsides

b.    Ixodes

c.    Dermacenter

d.    Boophilus

e.    Rhipicephalus

2.4   Describe the life cycles for hard ticks and soft ticks.

2.5   Identify (from images or whole specimens) different genera of mites. Representative mite genera may include (but are not limited to):* 

a.    Sarcoptes

b.    Notoedric

c.    Psoroptes

d.    Otodectes

e.    Demodex

2.6   Identify and/or list the diseases caused, life cycle, common names and means of transmission for the mites listed under section 2.5. *

2.7   Differentiate between arachnids and insects.

2.8   Recognize and identify members of the following orders: *

a.    Anoplura

b.    Mallophaga

c.    Siphonoptera

d.    Diptera

2.9   Identify (from images or whole specimens) different genera of insects. Representative insect genera may include (but are not limited to):*

a.    Haematopinus

b.    Linognathus

c.    Bovicola

d.    Trichodectes

e.    Ctenocephalus

f.    Tabanus

g.    Musca

h.    Sarcophaga

i.    Gastrophilus

j.    Melophagus

2.10  Give common names to the above insects.

2.11  Identify the canine and feline flea. *

2.12  List three diseases transmitted by fleas.

2.13  List three diseases transmitted by lice.

2.14  Define the following:

a.    Nits

b.    Pediculosis

2.15  Describe generalized life cycles for: *

a. Lice

b. Fleas

c. Flies

d. Gastrophilis

3.0   PHYLUM NEMATODA

INSTRUCTIONAL GOAL:

The goal is for students to become familiar with the more common members of the phylum Nematoda, their life cycles, and diseases caused by parasitic worms found in this phylum.

OBJECTIVES:

3.1   List four characteristics of the phylum Nematoda.

3.2   Identify and differentiate nematodes by use of adult specimens, eggs, microfilaria, or host symptoms. Representative nematodes may include (but are not limited to):*

a.    Ascaris

b.    Toxocara

c.    Ascaridia

d.    Ancylostoma

e.    Strongyloides

f.    Trichinella

g.    Haemonchus

h.    Habronema

i.    Spirocerca

j.    Dirofilaria

k.    Parascaris

l.    Osteragia

m.    Trichostrongylus

n.    Nematodirus

o.    Cooperia

p.    Oesophagostomum

q.    Small equine strongyles

r.    Oxyuris

s.    Dictylocaulus

t.    Setaria

u.    Hyostrongylus

v.    Globocephalus

w.    Metastrongylus

x.    Stephanurus

y.    Syngamus trachea

z.    Aelurostrongylus

aa.   Hetarkis

bb.   Muellerius

3.3   Identify, specifically, where in the host’s body each of the above nematodes would be found and what  type of specimens would be needed for identification.

3.4   Describe the life cycles, infective stage, pathogenicity and disease syndromes for the above nematodes. *

3.5   Identify by generic and common name the intermediate hosts involved in life cycles.

3.6   Identify a general geographic range for the above roundworms.

3.7   Identify the common names given to each nematode and common names to diseases produced by each nematode.

3.8   Recognize anatomical features used to identify the above organisms.

3.9   Differentiate the rhabditiform and the filariform larvae of the following:

a. Hookworm

b. Strongyloides

c. Trichostrongyles

3.10  Discuss the free-living and parasitic stages of life cycles and the importance of each.

3.11 Know the complex anatomy of the nematodes.

3.12 Identify zoonotic nematodes.

3.13  Know how nematode life cycles affect treatment and control. *

3.14  Understand the scotch tape diagnostic test for pinworms.

3.15  Discuss clinical case histories and how lab tests, life cycles and logic aid in diagnosis.

4.0  ACANTHOCEPHALIDS

INSTRUCTIONAL GOAL:

The goal is for students to recognize the spiny-head worms and be able to differentiate them from nematodes.

OBJECTIVES:

4.1   Describe the life cycle, infective stage, and normal definitive host for the Acanthocephalids.

4.2   Identify the common name for this group.

4.3   Differentiate this group from the Nematodes.

5.0  CESTODES

INSTRUCTIONAL GOAL:

The goal is to be able to recognize and characterize the more common tapeworms by use of anatomy egg appearance, and life cycle for each organism.

OBJECTIVES:

5.1   Identify and be able to differentiate tapeworms by use of either adult specimens or eggs. Representative tapeworms may include (but are not limited to):*

a.    Anoplocephala and Paranaplocephala

b.    Taenia sp.

c.    Dipylidium caninum

d.    Echinococcus sp.

e.    Monezia

f.    Thysanoma

g.    Hymenolepis

h.    Raillietina

i.    Davainea

5.2   Identify, specifically, where in the host’s body each  of the above tapeworms would be found and what type of specimens or testing would be needed for diagnosis.

5.3   Describe the life cycles, infective stage, pathogenicity and disease syndromes for the above tapeworms. *

5.4   Identify a general geographic location for each of the above tapeworms.

5.5   Give common names to the above cestodes.

5.6   Identify anatomical structures of adult and larval tapeworms. *

5.7   Identify those tapeworms that use the cysticercus and those that use the cysticercoid to infect  the definitive host.

5.8   Discuss zoonoses and the danger of hydatid disease.

5.9   Differentiate the species of tapeworms from eggs or gravid proglottids. *

5.10  Identify those tapeworms, which do one of the following:

a.    Pass the whole proglottids

b.    Pass eggs only

6.0   TREMATODES

INSTRUCTIONAL GOALS:

The goal is to be able to recognize and characterize the more common flukes by use of anatomy, egg appearance, and the life cycle of each organism.

OBJECTIVES:

6.1   List three characteristics of the class Trematoda.

6.2   Identify and differentiate flukes by use of either adult specimens or eggs. Representative flukes may include (but are not limited to):* 

a.    Fasciola hepatica

b.    Fascioloides magna

c.    Dicrocoelium     

d.    Nanophytes

e.    Paragonimus

f.    Paramphistomum

6.3   Identify, specifically, where in the host’s body each of the above flukes would be found and what type of specimens and lab tests would be needed for identification.

6.4   Describe the life cycles, infective stage pathogenicity and disease syndromes for the above trematodes. *

6.5   Identify a general geographic location for each of the above trematodes.

6.6   Give common names for the above flukes.

6.7   Identify distinguishing anatomical characteristics of flukes.

6.8   List three techniques used in fluke diagnosis.

7.0   PROTOZOA

INSTRUCTIONAL GOAL:

The goal is to recognize those protozoa, which cause disease symptoms, and be able to discuss their life cycles, pathogenicity, diagnosis, and treatment.

OBJECTIVES:

7.1   Describe the life cycle, infective stage, pathogenicity, disease syndromes, diagnosis, and treatment of protozoa. Representative protozoa may include (but are not limited to):*

a.    Giardia

b.    Isospora

c.    Toxoplasma

d.    Babesia

e.    Sarcocystis

f.    Haemobartonella

g.    Histomonas

h.    Trichomonas

i.    Leukocytozoan

j.    Hexamita

k.    Plasmodium

l.    Eimeria

m.    Anaplasma

n.    Trypanosoma

o.    Balantidium

p.    Eperythrozoan

q.    Entamoeba

r.    Cryptosporidium

7.2   Identify to group by means of locomotion

7.3   Understand cyst stages as protection in environment.

7.4   Identify in lab and understand lab tests.

7.5   Know how each protozoan deals with transmission to new host.

7.6   Know protozoan anatomy.

8.0   LABORATORY COMPETENCIES

INSTRUCTIONAL GOAL:

The goal is to develop an understanding for the proper procedure in the collection, processing, and evaluation of fecal, urine, blood, hair, skin, or tissue samples to be used for parasite identification.

OBJECTIVES:

8.1   Demonstrate parasitology diagnostic techniques and know the reasoning behind each test. Tests that are italicized with an asterisk: Demonstration of proficiency is required by our accreditor. Other tests may include (but are not limited to) the non-italicized, non-asterisk items on this list. 

a.    Centrifugal ZnSO4 fecal flotation *

b.    Passive fecal flotation*

c.     MgSO4 flotation

d.    Direct smear *

e.    McMaster fecal egg count

f.     Baermann Test

g.    Sedimentation technique *

h.   Knott’s Test*

j.    Buffy Coat Test

k.   Wet Mount Direct Heartworm Test*

l.    Occult ELISA Heartworm Test *

m.  Skin Scraping Analyses *

n.    Scotch Tape Test

o.    Squash prep for tapeworm proglottids

p.   Direct identification of adult parasites

8.2   Demonstrate objects found in fecal floatations and smears that are not parasites, but may be confused as parasites, i.e. the “pseudo-parasites” such as pollens and yeast.