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85 Cards in this Set
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Zinc Sulfate Centrifugal Flotation
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-Best used for standard fecal examinations
-Only technique for Giardia -Best technique for Trichuris eggs (whipworm) -Will recover most nematode larvae Problems: -Trematode, acanthocephalan, Pseudophyllidean tapeworm, Physaloptera eggs may not always float |
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Saturated Sugar Centrifugal Flotation
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-Gold standard for fecal examinations
--higher specific gravity will float more eggs -Giardia cysts will crenate Problems: -Trematode, acanthocephalan, Pseudophyllidean tapeworm, Physaloptera eggs may not always float -Saturated sugar solutions are sticky and messy |
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Passive flotation with saturated sucrose, saturated salt, or zinc sulfate
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-Standard technique used in many vet clinics
-Simplest method for separating parasite eggs and cysts from feces -Mix feces with a flotation solution of higher specific gravity than eggs --eggs float to top -Will miss most giardia cases -Will miss mild whipworm cases -Commercial devices allow examination of only small amount of feces -Trematode, acanthocephalan, Pseudophyllidean tapeworm, Physaloptera eggs may not always float -Saturated sugar solutions are sticky and messy |
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Ethyl Acetate Sedimentation
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-Best technique for examining samples with a large amount of fat
-Fat will float to top, prevents parasite egg recovery -Ethyl Acetate dissolves fat in feces and can be removed via centrifugation -Eggs are more concentrated -Best for samples with trematiode of cestode eggs -May take a long time to examine sediment of not combined with a different flotation technique |
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Baermann Technique
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-Best technique for recovering live nematode larvae for identification
-Involves use of Baermann Apparatus -Takes a minimum of an hour to run -Will only recover nematode larvae -Feces must be fresh, process requires live larva -Samples with only a few larvae may have to be run overnight |
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Direct Wet Mount
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-Least useful technique
-Should be used only on liquid feces -Look for protozoal trophozoites only -Used as an adjunct to a fecal flotation technique -Useful adjunct test with combined with staining technique -Examines only a small amount of feces -takes a very long time to examine sample properly |
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Invertebrate Taxonomy
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Protozoa
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-Single celled animals
-Classes are organized around structures for locomotion --Flagellum (Flagellates) --Pseudopodium (amoeba) --Cilia (Ciliates) --Coccidia (no structures) -Most are microscopic |
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Nematodes
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-Phylum: Nemathelminthes
-Class: Nematoda -Cylindrical in shape, tapering at both ends -Have complete digestive system -Body is covered by a cuticle -"Roundworms" due to shape in cross-section |
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Flatworms
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-Phylum: Platyhelminthes
-Trematodes (flukes) and Cestodes (tapeworms) -Flattened dorso-ventrally -Bilaterally symmetrical -Lack true body segmentation, body cavity, and anus |
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Trematodes
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-Phylum: Platyhelminthes
-Class: Trematoda -Flattened dorso-ventrally -Blind gut and no coelom/body cavity -Have suckers for attachment to the host -"Flukes" |
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Fasciola Hepatica
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-Trematode
-Lives in bile duct of ruminants, horses, and other mammals as adult -Diagnostic stage is egg passed in feces -Egg has operculum at one end --May not float in standard saturated salt solution --Have to use sedimentation method to concentrate the feces to diagnose infection |
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Cestodes
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-Phylum: Platyhelminthes
-Class: Cestoda -Ribbon-shaped organisms -Body is made of many repeating segments -No digestive tract or body cavity -Adults are always found in some part of hosts digestive tract -"Tapeworms" |
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Taenia taeniaeformis
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-Adult tapeworm
-Found in small intestine of cats -Can be up to 60 cm long |
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Taenia taeniaeformis egg
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-Diagnostic state for infection in cats is the gravid proglottid, passed in feces
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Gravid Proglottid
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-Egg filled with segment of worm
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Arthropods
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-Phylum: Arthropoda
-Bilaterally symmetrical -Paired, multi-jointed appendages -Exoskeleton of secreted, non-cellular material --usually chitin or CaCO3 -Dorsal heart and ventral nerve cord -Segmented bodies -Cold-blooded -Can act as ecto and endo parasites, can transmit other parasites of microbial pathogens |
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Arachnids
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-Phylum: Arthropoda
-Class: Arachnida -All characteristics of phylum arthropoda -Chitinous exoskeleton -4 pairs of legs in adult stage |
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insects
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-Phylum: Arthropoda
-Class: Insecta -All characteristics of phylum arthropoda -Exoskeletons are chitin and cross-linked proteins -Adult stages have 3 pairs of legs -Bodies are divided into 3 segments --head, thorax, abdomen -True flies, fleas, lice |
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Bursate nematodes
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-Strongyle-type nematodes
-Males have copulatory bursa at posterior end --wraps around the female during mating -Live in intestine of hosts -Have strongyle-type eggs --thin shell --8-16 cell morula inside --passed in feces |
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Strongyle-type Eggs
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-Produced by most bursate nematodes
-Oval in shape --may be pointed at one end or both ends in certain species -Clear, Thin shell -9-16 cell morula visible inside --number of cells present depends on amount of time egg has been out of host -Passed in feces -Most hatch and develop to L3 on pasture -77x34 micrometers → 100x50 micrometers, depending on species |
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Hookworms
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-bursate worms
-Anterior end is bent 90 degrees --mouth is on the side of worm instead of at the front -Live in intestines of the host -Eggs are 60-70 micrometers long -Only common strongyle-type worms found in dogs and cats in USA |
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Strongyle-type eggs in feces of dogs and cats
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-indicates infection with hookworm
-Ancylosotma caninum in dogs -Ancylostoma tubaeforme in cats |
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Ancylostoma caninum
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-Canine hookworm
-worm is the size of a fingernail --2-3cm -has buccal "teeth" -found attached to the small intestine of dogs -Only bursate worms in intestines of dogs in US -One worm can such 0.2ml of blood per day -Bigger than Uncinaria stenocephala -Ancylostoma tubaeforme is identical to Ancylostoma caninum, but is only found in cats |
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Uncinaria Stenocephala
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-In wild and domestic canines
-Common in europe and canada, range extends into US -Has cutting plates instead of teeth -eggs are larger than ancylostoma -adult is somewhat smaller and thinner than Ancylostoma -males: 5-8.5mm -females: 7-12mm |
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Fecal egg Count Reduction Test (FECRT)
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-defines drug resistance
-count eggs before treatment and after, and compare -Reduction of less than 90% indicates worms are resistant to the drugs used -Usually done at the herd level to reduce variation (1-(post-Tx count/pre-Tx count))*100= % reduction |
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Haemonchus Contortus
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-largest of the nematodes found in abomasum
-2-3cm long -Adult female has white ovaries wrapped around intestine --gives impression of a "barber-pole" -male worm has asymmetrical dorsal ray and a copulatory bursa -Number of Haemonchus contortus in a sheep or goat can be estimated via FAMACHA chart |
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FAMACHA chart
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-measures level of anemia in an animal
-Greater the level of anemia the greater of Haemonchus contortus --blood loss is directly related to worm number -Qualitative assessment |
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Worms in equine intestinal contents
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-Strongylus vulgaris (1 inch)
-Strongylus edentatus -Strongylus equinus (2-3 inches) -Cyathostoma -Other small strongyles -Anoplocephala perfoliata (tapeworm) Color is not a good defining characteristic |
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Nematodirus Egg
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-Egg is similar to strongyle-type eggs
-larger than strongyle-type --175x75 micrometers → 200x90 micrometers -Easily recognizable by size |
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Abomasal Nematodes of Ruminants
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1. Haemonchus
-common in abomasum of sheep, goats, cattle, other ruminants -20-30mm long -"barber-pole"= spirally wound ovaries 2. Osteragia 3. Trichostrongylus -smallest of abomasal nematodes |
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Osteragia
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-"Brown stomach worm," darker in color
-intermediate in size, smaller than haemonchus and larger than trichostrongylus -Found in sheep abomasum -1cm long -Male: 7.5-8.5 mm -Female: 10-12mm |
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Trichostrongylus aei
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-smallest of abomasal nematodes
-less than 7mm long --male: 4-5mm --female: 5-7mm -light color makes them hard to see |
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Ollulanus tricuspis
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-stomach worm of cats and pigs
-Oviviparous nematode, gives birth to larva not eggs -transmitted via viomiting -feed on stomach wall --produce ulcers that lead to vomiting -Individual must eat vomit to become infected -Dx: finding adults or larvae in the vomit |
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Large strongyles
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-In large intestine of horses
-Strongylus vulgaris (smallest) -Strongylus edentatus -Strongylus equinus |
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Strongylus vulgaris
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-Smallest of large strongyles found in the horse
-1.5-2.5 cm long -large buccal capsule with 2 dorsal ear-shaped teeth |
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Strongylus edentatus
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-larger "large strongyle" in horse intestine
-2.5-4.5 cm long -No teeth in buccal capsule -very "robust" worm -Looks like Strongylus equinus grossly |
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Strongylus equinus
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-larger of the large strongyles in horse intestine
-2.5-5cm -3 cone-shaped teeth in the buccal capsule -Looks like Strongylus edentatus grossly |
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Cyathostomum
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-Small strongyles of the horse large intestine
-less than 1.5 cm -Buccal capsule is shallow, contains no teeth -More than 40 species of small strongyles exist in horses --any horse will have 10-20 different species at one time |
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Bunostomum
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-Hookworm in sheep and cattle
-Large hookworm --males: 14mm --females: 24mm -has cutting plates in mouth capsule of adult -Can be identified by the mouth capsule and cutting plates |
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Ancylostoma tubaeforme
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-hookworm found in cats in US
-Identical to Ancylostoma caninum |
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Cooperia
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-Bursate worm of ruminant small intestine
-small worm --males: 4.5-5.5mm --females: 5.8-7.2mm -tightly coiled, looks like a "watchspring" or fiddlehead -Cuticle of the anterior end is slightly swollen and striated -Found in the small intestine of sheep |
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Nematodirus
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-Bursate worm of ruminant small intestine
-Long, thin worm --male: 10-15mm --Female: 15-23mm -Spicules of the male may extend past the bursa -Egg is twice the size of any other strongyle-type egg |
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Oesophagostomum
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-"Nodule worm"
-Only bursate nematode in colon of ruminant and pig hosts -causes formation of nodules in the intestine -Acute disease is associated with the larvae -Eggs are not usually present in the feces -Lives in large intestine of ruminants and pigs -Male: 8mm -Female: 12mm |
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Stephanurus
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-Large, stout worm
-Found around and in the kidneys of pigs --in cysts that open to hilus of kidneys and ureters -Fresh specimens are pinkish in color -Strongyle-type eggs are found in urine of infected animal -Main pathological effects occur during prepatent phase -Male: 25mm -Female: 35mm |
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Bursate nematodes of poultry
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-Syngamus trachea
-Occurs in the trachea of turkey, goose, fowl, and various wild birds -Found in permanent copulation, forming "Y" shape -Male: 2-6mm -Female: 5-20mm |
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Ascarids
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-Large parasitic nematodes
-Usually live in the lumen of the small intestine of host -All have 3 lips around mouth -No buccal capsule |
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Pinworms
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-Female has long, narrow tail
-Live in the large intestine of host -Oxyuris equi |
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Trichocephalids
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-All have stichosome that is part of esophagus
-Stichosome is a long slender tube surrounded by row of large glandular cells -Whipworms, capillarids, and trichinella |
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Toxocara Canis Egg
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-Egg= 80x75 micrometers
-Surface of egg is pitted like a golf ball -is round and contents fill shell cavity -cannot be differentiated from Toxocara Cati on microscope -Brown -Thick, pitted protein coat -Look like little eyeballs |
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Toxocara Cati Egg
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-Egg= 75x65 micrometers
-Surface of egg is pitted like a golf ball -round and contents fill shell cavity -cannot be differentiated from Toxocara Canis on microscope |
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Toxascaris leonina Egg
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-Egg= 80x65 micrometers
-Smooth shell to egg - is slightly ovoid -contents do not fill the shell |
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Trichuris vulpis Egg
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-Eggs are 80x40 micrometers
-Lemon shape with plugs at both ends -Light brown color -Smooth surface to shell -Thick shell -Only seen in dogs |
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Ascaris suum
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-Eggs are 60x45 micrometers
-Some eggs have proteinaceous outer layer, some have lost the outer layer -Only ascarid egg in swine |
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Pasacaris equorum egg
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-Eggs are 90-100 micrometers
-Lighter gray/brown color -rough exterior on shell on some, some not, makes egg sticky -Only ascarid egg in horses |
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Baylisascaris procyonis egg
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-Eggs are 70x60 micrometers
-Similar appearance to toxocara, but is "lumpy" due to globular proteins on surface -Surface of shell has fine granular appearance -common parasite of raccoons, will also infect dogs -Brown rough shell wit lighter brown interior |
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Ancylostoma Caninum Egg
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Oxyuris Equi egg
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-90x42 micrometers
-operculum/cap at one end -eggs can be found in the feces, not usually seen on flotation -female deposits eggs on skin of perianal area, can scrape region to find eggs -football shaped, plug at one end, slightly uneven |
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Trichinella spiralis
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-causal agent of trichinosis
-migrating L1 cause important pathology -female adult gives birth to L1 --L1 migrate and encrypt in the muscles --nurse cell surrounds larvae in muscle, rearranges striated muscle to make it more accommodating -Inflammatory cells may be around larvae during acute phase of infection -L1 encrypted in muscle tissue is diagnostic stage |
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Ascaridoidea
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-ascarids
-large nematodes that usually live in small intestine -3 lips around mouth opening -no buccal capsule -eggs are thick-shelled and unsegmented -eggs embryonate in feces or fecally contaminated soil -L2 is ingested via paratenic host or by vertical transmission through milk --vertical transmission is particularly important in dogs (prenatal in-utero) and cats (transmamma |
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Ascaris suum
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-largest nematode of the pig
-can get up to 40cm long -located in the small intestine of pigs |
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Ascaris suum egg
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-60x45 micrometers
-rough proteinaceous coat -Only ascaris of pigs |
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Parascaris equorum
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-Largest nematode of the horse
-up to 40cm long -Long worm, in small intestine of horse -Occasionally noticed in the feces of infected animals -3 lips on anterior end of worm |
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Toxocara canis adult
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-Large (18cm) worm
-In small intestine of dog -Largest canine nematodes in the small intestine |
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Toxascaris leoeonina adult
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-Ascarid found in both dogs and cats
-Adults are up to 10cm -Look a lot like toxocara canis adult worms |
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Toxocara Cati adult
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-Broad alae that end abruptly
-Can see alae without microscope -End has "arrowhead" appearance due to alae |
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Baylisascaris procyonis
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-Ascarid of raccoons
-Can cause fatal visceral larval migrans in other animals -highly neurotropic larvae --males are especially pathogenic |
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Ascaridia galli
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-largest nematode of poultry
-Worm lives in small intestine -Size and predilection site are diagnostic -Females: 72-116mm |
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Heterakis gallinarum
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-Small nematode in large intestine and cecum of poultry
-Occur in birds raised on the ground -Can be a vector for Histomonas meleagrides (blackhead) -Size and predilection site is diagnostic |
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Trichuris vulpis adult
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-Adult whipworm of dogs
-found in cecum and large intestine -Narrow anterior end and shorter, thicker posterior end, give worm appearance of a whip -Disease is caused by worms penetrating epithelial cells of cecum and colon with narrow anterior end |
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Capillaria aerophilia eggs
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-Parallel sides of eggs
-Bipolar plugs, usually asymmetrical -Rough surface to eggs |
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Oxyuris equi adult
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-Pinworms found in large intestine of horses
-Female is 10 cm with long, pointed tail -Adult can be recovered in feces -Males are less than 1 cm long --can be confused with small strongyles -Found in cecum, large intestine, and rectum |
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Dioctophyma renale
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-Giant Kidney Worm
-Largest nematode parasite of dogs -60cm long -found in kidney, replaces kidney tissue -Host survives because only one kidney is infected -Eggs found in urine -Found in mammals that eat fresh water fish |
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Serodiagnosis
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-Serological method for detecting D. immitis
-Quick, accurate, and semi-quantitative methods for diagnosing infection with adult heartworms -Does not need microscopic examination of blood -Can be used to diagnose occult infections -Detect serum from circulating antigen of the female worm |
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Mullerius capillaris L1
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-Typical lungworm L1 with kinked tail
-Adults are in lungs of ruminants -Eggs hatch in lungs -L1 is passed in feces -Sub-terminal spine at base of the tail -Common in goats in this area, sometimes in sheep -First detected on fecal float -Adults are found in liver parynchema |
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Dictyocaulus viviparous
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-Adults live in bronchi of cattle
-Slender, 6cm long worms -Straight tail -Technically a trichostrongyle but has larvae in feces and adults in lung --acts like metastrongyle -Detected in fecal float |
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Aelurostrongylus abstrusus
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-Lungworm in cats that hunt and eat mice
-L1 found feces -Kinked tail with subterminal spine -Usually seen on fecal float -Eggs laid and hatch in lung of cat |
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Oslerus osleri
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-Lungworm
-Larvae found in fresh dog feces -Kinked tail -Can be found in septum of animal if it is coughing (tracheal wash) |
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Strogyloides stercoralis
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-Threadworm of dogs
-L1 found in feces of dogs and primates -L1 have straight tail and large genital primordium --oval group of cells located between body and intestine about halfway down the worm -Short esophagus (25% of body) -No males in parasitic portion of life cycle |
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Strongyloides ransomi
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-from intestine of pig
-Small size -only females found in the host |
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Strongyloides egg
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-Smaller than strongyle eggs
-Thin clear shell -Egg contains almost fully developed embryo when in feces Most commonly seen in younger animals -Strongyloides papillosus in ruminant -Strongyloides westeri in horses -Strongyloides ransomi in pigs |
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Dirofilaria immitis adults
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-Heartworm
-Adults live in pulmonary arteries of dogs, cats, coyotes, ferrets, seals -With heavy infection can extend retrograde into right atrium and vena cava -Females are 25-30cm |
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Dirofilaria immitis Microfilaria
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-Found in peripheral tissues of skin or peripheral blood circulation
-Tapered at one end -Lack a gut, are a motile bag of cells -Usually a straight body and slightly curved tail -Knott test is used to determine species of microfilaria |
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Spirocerca lupi eggs
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-Very small size
-Oval -Thick shell -Parallel-sided appearance -Passed in feces with L1 coiled in egg --ONLY larvated eggs in fresh dog feces -Looks like a paperclip in a jellybean |
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Spirocerca lupi adults
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-Esophageal worm of dogs
-Forms nodules in esophagus -Nodule can go on to become a neoplasm -Nodule is visible on radiographs -large worms, usually coiled -Pink to red color -Usually a sub-tropical worm, but has been spreading |
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