Flashcards in Mid Term Deck (97):
Diseases are often categorized into what 2 categories according to the causes?
infectious and non-infectious
What kind of diseases are caused by non-living agents?
What kind of diseases are caused by living agents?
What is a microorganism?
living organisms that are microscopic in size
Can microorganisms be unicellular or multicellular?
they can be both
Microbes have the capacity to reproduce at a rapid rate under what kind of conditions?
What are the 2 broad groups of microbes?
saprophytes and pathogens
Saprophytes are the ______
Pathogens are the _______
Saprophytes are what?
important for survival
Pathogens do what?
Saprophyte organisms aide all higher forms of life in what?
Pathogens are what?
What is the first line of defense against pathogens?
What is the second defense against pathogens?
antibodies and/or phagocytes
What are phagocytes?
the cells that ingest microorganisms or other cells
What happens when the defenders fail?
invading organisms overpower the body
Who provides habitat and food for the parasite?
Who always does some degree of damage?
What are the most successful groups of parasites today?
protozoa, helminths, and arthropods
Control of parasitism should begin before what?
obvious clinical signs appear
How may animals appear when parasitism occurs?
unthrifty, poor haircoat, poor appetite, dehydration, diarrhea, weight loss, weakness, pale mucus membranes
how do endoparasites damage their hosts?
absorb food intended for the host, sucking blood and lymph from host, damaging tissues which may lead to internal bleeding, creating mechanical obstructions, produces toxic substances, providing entry for infectious organisms, altering RBC shape and function
How do ectoparasites adversely affect their hosts?
by damaging and irritating the skin, sucking blood, creating excitement, restlessness and nervousness by their presence, transmitting infectious organisms
What is a direct life cycle?
only one definitive host and may have a free-living stage
What is a indirect life cycle?
with one definitive host and one or more intermediate hosts. They may also have a free-living stage
What kind of life cycle does a protozoa have?
both direct and indirect
What kind of life cycle do cestodes have?
Indirect. Nearly always have one or more intermediate hosts
What kind of life cycle do nematodes have?
have both types of life cycles and usually four molts to become adults
What are incidental parasites?
individuals of a species that wander to unusual places in the normal host
What are the main groups of endoparasites?
nematodes, cestodes, trematodes, protozoa
What are nematodes?
roundworm or helminths
What are cestodes?
What are trematodes?
What are the two main groups of arthropods?
arachnids and insects
What are some intestinal nematodes?
large roundworms, hookworms, and whipworms
What is the scientific name for whipworm?
What animals does Trichuris vulpis affect?
canine and feline
What life cycle does Trichuris vulpis have?
Where are Trichuris vulpis found?
large intestine and caecum
What do Trichuris vulpis do to the host?
How long is Trichuris vulpis prepatent?
6 weeks to 3 months
How are "colic" situations created in horses?
What is Parascaris equorum?
Where do Parascaris equorum inhabit?
What kind of life cycle does Parascaris equorum have?
What are some clinical signs of Parascaris equorum in foals?
decreased growth and debilitation, sometimes death
What can adult horse roundworms cause?
intestinal obstruction or rupture
What do foals exhibit when they have roundworms?
rough hair-coat and "pot belly"
How can you control Parascaris equorum?
de-worm pregnant mares, manure disposal, do not overcrowd
What are some nematodes (the strongyles) of the Equine?
Strongylus vulgaris, Strongylus equinus, Strongylus edentatus
Where do "Strongyles" inhabit?
the cecum and small intestine
Why are strongyles sometimes called bloodworms?
they ingest blood creating dark colored adult worms
What kind of life cycle do strongyles have?
When do strongyle larva develop?
to infective third stage on pasture
What is critical for strongyle larva survival?
moisture and warmth
How are strongyles transmitted?
through ingestion of the third stage larval while grazing
Which strongyle is the most pathogenic of the group?
What are trichostrongyles?
What is Haemonchus contortus?
twisted stomach worm, wire worm, barber pole worm
What does Haemonchus contortus inhabit?
abomasum and consumes blood
what kind of life cycle do Haemonchus contortus have?
What are some clinical signs of Haemonchus contortus?
unthrifty, weight loss, "bottle jaw"
What is Nematodirus spp?
What does Nematodirus spp inhabit?
small intestine of ruminant
What are some clinical signs of Nematodirus spp?
decreased appetite and decreased weight gain, diarrhea and dehydration, death in lambs
What is Ctenocephalides felis?
What happens in stage 1 of Ctenocephalides felis?
1/3 of population in owners home and female lays eggs daily
What happens in stage 2 of Ctenocephalides felis?
57% of population are larval, caterpillar-like, grazing on "flea dirt", stage at which pick up tapeworm eggs
What happens in stage 3 of Ctenocephalides felis?
most young fleas have been killed off, only 8% make it to this stage
What happens in the final stage of Ctenocephalides felis?
they wait until they detect a nearby host
How do fleas detect a host?
vibrations, carbon dioxide, sound, light and heat
How long can fleas live unfed?
How long can fleas live without a host?
a few weeks
When do female fleas begin to produce eggs?
within 24-28 hours
What is FAD?
Flea Allergy Dermatitis
What should you do before FAD can be cured?
What is Dipylidium caninium?
What is Otedectes cynotis?
Are mites arachnids or insects?
Where do mites live?
on surface of the ear canal skin
What animals are mites found?
cats, dogs and rabbits
What are some symptoms of mites?
dark waxy deposits and exudate in the ear canal, irritation, inflammation
What may result from mites?
secondary bacterial infections
How long after mite eggs are laid do they hatch?
What are some concerns with ear mites?
hematoma, partial hearing loss, self-trauma and disfigurement
The time between invasion by a parasite and the recovery from the host of some new stage in the development of the parasite. The presence of the parasite within the host is difficult or impossible to detect
The time during which the presence of the parasite in the host can be detected by laboratory methods
The propensity of a parasite to infect only one given species of host. The parasite can exist in only one specific species
a word termination denoting a process, especially of a disease
a process of the condition resulting therefrom, especially of a disease
denoting a state or condition
denoting a state or condition
signifying a state or condition
The organism that harbors the sexual (adult) stage of the parasite
An organism that alternates with the vertebrate host and harbors the asexual (immature) stages of the parasite