General knowledge

What are 4 things to look at when trying to identify a parasite?

• Size

• Shape

• Cell Wall

• Nucleus

What is “Parasitism”?

When one organism (the parasite) benefits while the other organism (the host) is harmed.

List 6 effects that parasites can cause

• Nutrient Loss

• Obstruction

• Tissue Damage

• Disease Transmission

• Economic Loss (skinny cow = less money)

• Poor Body Condition

What are the 4 steps to take to effectively deal with Parasitism?

1. Complete Medical Workup (Hx)

2. Diagnostics (fecal, blood smear)

3. Prescribe Tx

4. Follow up on efficacy of Tx

What are 3 major things to consider when looking at the toxicity of therapeutic drugs?

• Hepatic Damage

• Allergic Response

• Neonatal, Reproductive, Developmental Damage

Define a “Definitive Host”

The host in which a parasite reaches sexual maturity and/or undergoes sexual reproduction.

Define “Intermediate Host”

The host in which a parasite undergoes larval development and/or asexual reproduction, but does not reach sexual maturity

Define a “Paratenic/Transport Host”

• May carry the parasite but no maturation takes place (an accidental host)

• Not required to complete the parasites life cycle

Define a “Spurious Host”

Host that passes parasite eggs or stages in feces without being infected, usually after ingesting parasites or eggs from another animal

What is an “Indirect Life Cycle”?

• Parasite must pass through a second (intermediate) host species

• Definitive Host > Enviroment > Intermediate Host > Definitive Host

What are the 4 “Migration Patterns”?

• Mucosal

• Trans-Tracheal

• Somatic

• Visceral

What si “Mucosal Migration”?

• remains in intestinal tract once ingested

• no zoonotic concern

What is “Trans-tracheal Migration”?

• immature larvae leave GI tract, move into lungs via lymphatic system

• Coughed up, swallowed, and return to GI to complete maturation

• Pneumonia

What is “Somatic Migration”?

Larval parasites migrate through body tissues, become arrested, and may reactivate later

What is “Visceral Migration”?

Larval parasites migrate through internal organs as part of their normal life cycle, eventually reaching adult size

What is “Zoonosis”?

Disease of animals transmittable to humans

(Somatic, visceral)

Define the “Pre Patent Period”

The parasite is sexually immature and incapable of reproducing

Define the “Patent Period”

Time in the host when the parasite is sexually mature and producing ova

Define “Pre patent Infection”

Disease process is caused by the immature form of the parasite

Define “Patent Infection”

When the disease process is caused by the mature form of the parasite

What is the difference between “sp” and spp”

Sp- one species

Spp- multiple species

What are 3 ways that parasites can move from host to host?

• fecal oral route

• Skin penetration

• Direct contact

What are the 4 main Phyla of Internal Parasites?

1. Sarcomastigophora

2. Nemathelminthes

3. Platyhelminthes

4. Acanthocephala

What is “Sarcomastigophora”?

Protozoans

• single celled organisms

• “Coccidia”

What are “Nemathelminthes”?

Roundworms

• majority of internal parasites

What are “Platyhelminthes”?

Flatworms

• class Cestodes - tapeworm

• Class Trematodes - flukes

Define “Insecta”

• 6 legs

• Flies, fleas, lice

• Most important as vectors for disease

Define “Arachnida”

• 8 legs

• Mites & ticks

Define “Larva”

Define “Vector”

Carrier that transfers an infective agent from one host to another (living or not)

What is a “Helminth”?

Parasitic worm

What are “Anthelmintics” or “Antihelminthics”?

Anti-parasitic drugs

What are “Nematodes”?

Roundworms

• largest group of internal parasites

• Have a mouth

• Life cycle = simple direct