Parasites Flashcards
difference between ectoparasites and endoparasites
Ectoparasites: live on outside of the host
Endoparasites: live within the host
Accidental parasite
when a parasite enters or attaches to the body of a species of host different from its normal one.
Definitive host
host in which parasite reaches sexual maturity and reproduces
Intermediate host
host in which some development occurs
Paratenic host
no parasite development
Obligate parasite
no free-living stage
Facultative parasite
free-living organism that can become parasitic in certain hosts
difference between a direct and indirect parasitic life cycle
Direct parasitic life cycle: parasite is transmitted directly from one host to another without an intermediate host or vector of different species
Indirect parasitic life cycle: requires intermediate host(s) for different stages of their life cycle
what is the common name for cestodes?
Tapeworms
what is the common name for trematodes?
flukes
In the basic nematode life cycle, where does the parasitic phase take place?
Takes place inside the definitive host
In the basic nematode life cycle, where does the pre-parasitic phase take place?
Either a free-living phase (environment) or inside a second host (intermediate host)
In what organ of the pig do Ascaris suum adults live? In what two organs do the larva migrate to? Know the clinical signs seen.
- Adults are found in the small intestine
- The larva migrate from the liver to the lungs
Clinical signs:
- Liver milk spots
- Weight loss
- “thumps” (abdominal breathing)
what is the intermediate host(s) for Ascaris suum?
Worms (large-round) or fecal
What does the “prepatent” period mean? How does this affect our ability to diagnose parasitism?
- period between infection and the first ability to detect the parasite in the body (often production of eggs by a female)
-Though fecal flotation and identification of eggs
What is the name of the parasite associated with heartworm disease of dogs and cats? What is the intermediate host?
- Dirofliria immitis
- Intermediate host is the mosquito
What is a microfilaria?
free-swimming embryonic stage found in the blood
where to adult heartworms live?
heart
is the disease more serious in cats or in dogs?
cats = death
how do we diagnose heartworm in cats?
- Antigen tests (female worms)
- Antibody tests
- Microfilariae
- Cardiac ultrasound
- radiographs
what are two limitations of the heartworm antibody test?
- Cannot distinguish between active and past infections
- Cannot detect recent infections
What are three reasons why the antigen test for heartworms may fail in an infected animal?
- Few worms present
- Immature females
- Male-only infections
What bacteria is associated with heartworm infection?
Wolbachia
How do we prevent heartworm disease in dogs and cats?
- Must control exposure of mosquitos
- Annual testing (year-round)
- Ivermectin, moxidectin, selamectin
