intro to parasitology

what is symbiosis

living together (sym=same, together)

what is phoresis

smaller member of the relationship is mechanically carried about by the larger (ph = f = free ride)

what is mutualism

both organisms benefit (mutual = both agree)

what is commensalism

one benefits and the other neither benefits nor is harmed

what is parasitism

one member lives on or in the other member and may cause harm (one benefits (tick) one is harmed (dog)

what is an infection

may be caused by parasite within the body (in = inside)

what is infestation

outside or on body or in the environment (infestation of lice = on head, infestation of bees = outside on tree)

what is multiple parasitism

condition in which parasites of DIFFERENT species infest/infect the animal

what is super parasitism

excessive parasitazion of the same species (super = a lot)

what is erratic or aberrant parasite

when a parasite wanders from its usual site of infection into an organ or location in which it doesn’t normally live (erratic = all over the place)

what is an accidental parasite

when a parasite occurs in a host that it normally doesn’t live (accident = not in right place)

what is an obligatory parasite

parasite that must live in or on a host to survive, grow, or reproduce (oblig = obligated to live somewhere else because it cannot live alone)

what is a periodic parasite

a parasite that does not have to live on or in a host but must make short frequent visits to obtain nourishment (periodic = here and there)

what is a pseudo parasite

living things mistaken for parasites but aren’t

what is a definitive host

host that harbors adult, sexual a,d mature stages of parasite

what is an intermediate host

the host that harbors the larval, juvenile, immature or asexual stages of the parasite (I = immature young)

what is a direct life cycle

parasite only needs one host to complete life cycle, does not need intermediate host, may develop or mature in environment before infecting an animal

what is indirect life cycle

parasite needs two or more hosts to complete its life cycle, requires intermediate host, develops in one host and eventually infects another host

what are transport hosts

intermediate host where no development occurs, way to get parasite from one host to another

what is somatic/tracheal migration

somatic = parasite travels through hosts tissues, organs, or blood (somatic = whole body), tracheal = parasite travels through lungs and respiratory tract (trachea = throat, lungs)

what is the prepatent period

time interval between when a parasite enters or infects a host and when it first becomes detectable (pre = before being detected)

what is the prepatent period for heart worms

6 months

what is the prepatent period of whipworms

3 months

what is the incubation period

time from when the parasite enters the host and the development or signs and symptoms (usually longer than prepatent period) (incube = trapped in body)

what are there major classes of parasites

helminths, arthropods, and protozoa (HAP)

what are helminths

worms, grouping together of nematodes, tapeworms, and flukes

what are arthropods

insects and arachnids

what are the characteristics of nematodes

round, longer than wide, unsegmented, variety of lengths, significant cause of disease in dogs and cats, have varied life cycles (diff stages of life, reproduction, infection, and survival) (ROUND, LONG, SMOOTH, VARIED)

what are the characteristics of tapeworms

flat, segmented, head has suckers that enable it to attach itself to animal intestines, each segment has its own reproductive organs, no digestive system, life cycle includes intermediate host (FLAT, DIVIDED, STICK (tape), REPRODUCE, ABSORB (no digestive system so they absorb things through skin)

what are the characteristics of flukes

flat, leaf shaped, unsegmented, suckers that attach to themselves to hosts organs, fluke eggs have trap door called operculum (allows larva to escape from egg when it hatches), dog and cat flukes have indirect life cycles, do not cause serious issue in dogs and cats unless in high numbers (FLAT, LEAF SHAPE, UNSEGMENTED, ATTACHES, OPERCULUM, SEVERAL HOSTS)

what are arthropods

members that all have jointed legs (arthr = joint)

how much % do insects make up of all known species

70%

what are the characteristics of arachnids

carnivores, feed on tissue and blood, related to spiders (ara = arañas, se comen las personas)

what are the characteristics of protozoa

over 450,000 species, composed of nucleus and cytoplasm, may move with assistance of flagella (P = plenty of species, R = region in cell (nucleus and cytoplasm), and O = organ of movement (moves w flagella)

what is a round worms scientific name

phylum nematoda (nematodes = worm)

what is phylum Nematoda commonly called

roundworms (nematodes = worms)

what is the anatomy of phylum nematoda

cylindrical body shape, multicellular, cuticle (tough outer protective covering of roundworm), hypodermic (layer directly underneath the cuticle, produces and supports cuticle, helps provide body structure, hypo=under), longitudinal somatic muscles (lengthwise, help worm move, LONG = length, MUSCLE = movement), have digestive tract, pseudocoelom (body cavity, fluid filled space that holds internal organs, coel=coliseo tiene collection de cosas), reproductive organs, NO respiratory system

what are the developmental stages of phylum nematoda

egg, four larva stages, sexually mature adult

what are the infective stages of phylum nematoda

egg containing larva (animal eats egg that already has developing worm inside), free living larva (larva lives in environment and enters an animal), larva within an intermediate host (animal eats another organism containing the larva allowing parasite to infect it)

what happens after a nematode enters a new host

it develops either near its final location or after migrating through the body (can move or stay)

what is extensive migration

parasite travels through diff organs or parts of body before reaching final location (extensive=long, long travels)

what is the diagnostic stage

the stage or evidence of a parasite that we look for to diagnose an infection (diag=diagnose)

where are nematodes or their diagnostic stages commonly found

feces, blood, sputum, urine, lungs, kidneys, bladder, and heart (pee, blood, lungs)

at what stage does the nematode become infective

L3

what is ascharoidea

superfamily of roundworms within the phylum nematoda (roid= round)

what are the three ascarids of dogs and cats

toxocara canis (canine = dog), toxocara cati (cati = cat), and toxascaris leonina (both)

where are ascarids found in dogs and cats

intestinal tract (intestines long like worms)

what is the common name for toxocara spp.

roundworms

how would you describe adult ascarids

large and robust (thick bodied)

how long can adult ascarids grow

3-18 cm (18 =-16.8 cm adult) (1-7 inches, 7 = fav)

what is the prepatent period of toxocara Canis (dogs)

21-35 days (21 divisible by 7, 7 = dog years)

what is the prepatent period of toxocaris leonine

74 days (7= dog, 4 = legs on cat and dog)

what shape are toxocara eggs

spherical (sphere = circle/round)

what do ascarids look like when they are passed in feces

theyre tightly coiled

what is this? how can it infect an animal, how is it treated, and how it is diagnosed

toxocara canis ova (dark)/roundworm , can infect an animal through its mother or through eating something thats infected, it is treated with deworming medication, and can be diagnosed through a fec@l exam

what is this? how can it infect an animal, how is it treated, and how it is diagnosed

toxocara cati ova (light) roundworm, can infect animal through eating something infected or through mothers milk, can be treated by giving deworming medication, and can be diagnosed through a fecal exam

what is this? how can it infect an animal, how is it treated, and how it is diagnosed

toxascaris leonina ova (bubble is closer to one side of cell more), can infect animal by eating infective eggs and eating infective prey, it is treated by giving dewormers, and diagnosed by fecal flotation exam.

what are some methods of transmission

direct (fecal/oral), transplacental (doesn’t apply to leonina or toxocara cati), transmammary (doesn’t apply to leonina), predation of foreign hosts, and zoonotic disease (toxocara cati is just passed to babies via milk)

what is the tracheal migration route

Dog swallows infective eggs from contaminated soil or food, Eggs hatch in the stomach, releasing larvae, Larvae penetrate the stomach wall and enter the blood circulation, Larvae travel to the liver, then to the heart and lungs, Larvae move up the trachea (windpipe) toward the throat, Dog swallows the larvae, which return to the stomach, Larvae develop into adults in the small intestine, Adult worms mate and produce eggs, which pass out in the dog's feces

what is the somatic migration route

dog consumes eggs, eggs hatch in stomach and enter blood stream, larvae migrates through liver tissue, larvae travel to assorted sites (muscles, mammary glands, etc) and encyst (hibernate), can later come out due to female dog/cat becoming pregnant due to hormonal changes, larvae can pass to babies

what can toxocara zoonosis cause in humans

visceral larval migrans (VLM, visceral = organs), ocular larva migrans (OLM, O=ocular/eyes), neural larval migrans (baylisascaris procynosis, brain)