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Parasitology. Dr. N. Matthew Ellinwood, D.V.M., Ph.D. March 6, 2014. Iowa State University College of Agriculture and Life Sciences. Bloody Feces. What tests should be run? Fecal float Fecal cytology (Fix and Stain, dead Direct fecal smear (Fresh, alive)
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Parasitology Dr. N. Matthew Ellinwood, D.V.M., Ph.D. March 6, 2014 Iowa State University College of Agriculture and Life Sciences
Bloody Feces • What tests should be run? • Fecal float • Fecal cytology (Fix and Stain, dead • Direct fecal smear (Fresh, alive) • Fecal antigen tests (more sensitive, more expensive than float)
Antigens • Any molecule that sometimes stimulates an immune response • Usually proteins or polysaccharides • Test for by using antibodies (in blood) http://www.poultry-health.com/library/serodiss/elisa13.jpg
Blood • Composed of plasma and cellular components • Plasma - liquid portion of blood • Serum - blood plasma with clotting factors removed • Serology
Antibody • Most look like Y • Binds to antigen on one of two arms that are specific to antigen • Can have protein conjugate • Enzymes bind substrates • Horseradish peroxidase • Colorometric technique
Antigen Tests • Antigens detected by antibody based technique • Use commercial antibody • ELISA test • Possible organisms to identify: • Giardia • Parvovirus
Cytology • Make thin layer of feces on glass slide with saline • Want bacteria to be completely separate • Heat fixation • Can use lighter • Aid in fixing sample to slide • Aid in uptake of stain
Cytology - Diff Quick • Alcohol • Basophilic stain (high pH - blue portion) • Eosinophilic stain • Use high magnification - oil for 100x
Clostridial Enteritis • Diarrhea • Stains at one end
Spore Forming Bacteria http://srs.dl.ac.uk/Annual_Reports/AnRep01_02/anthrax-bacteria.jpg • Anthrax • Botulism Anthrax http://www.foodhaccp.com/memberonly/0829.jpg
Sporulation • “Happy dog” diarrhea (unlike parvo) • Treat with antibiotics
Campylobacter • 1-2 in microscope is normal • 5-10 indicates disease
Direct Fecal Smear • Thicker than cytology • Smear on slide, add water or saline, and use coverslip • Giardia • Coccidia http://www.infectiousdiseasenews.com/200709/eistories2.jpg
Fecal Float • Feces in tube and mixed with solution • Place coverslip on top • Solution needs to be more dense than eggs • Saline - isotonic, not dense enough • Zinc sulfate - good, dense salt solution • Will effectively float organisms • Take coverslip off and put on slide
Centrifuged Float • Similar to fecal float but centrifuged • More accurate • Can be used efficiently with a lower number of eggs http://www.windyhollowvet.com/images/roundworm.gif http://pethealth.petwellbeing.com/w/images/3/3e/Dog_Whipworm_egg.JPG
Toxascaris leonina • Common name: Ascarid/roundworm • Size of adult: 6-17 cm in SI • Host: Dogs & Cats http://www.thepetcenter.com/exa/ascarids_3.jpg http://images.google.com/imgres?imgurl=http://www.uga.edu/~lam/kids/worms/Pics/round.jpg http://www.beaglesunlimited.com/Photos/CanineRoundworms.jpg
Trichuris vulpis • Common name: Whipworm • Size of adult: 3-8 cm in cecum • Host: Dogs http://www.angelhealingcenter.com/Paras12.gif cal.vet.upenn.edu/paralab/images/labimage/lab4/4_18.gif&imgrefurl http://images.google.com/imgres?imgurl=http://www.path.cam.ac.uk/~schisto/Pic
Ancylostoma caninum • Common name: Southern Hookworm • Size of adult: 8-16 mm in SI • Host: Dogs http://www.animalhealth.bayer.ca/content/pictures/Ancylostoma%20Caninum.jpg http://bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab-4b/Hookworm_1/Lab_4b-21a.jpg
Giardia canis • Common name: None • Flagellated protozoa • Size of organism: 10 x 18 µm • Hosts: Dogs, cats, humans, etc http://www.nih.go.jp/niid/para/atlas/images/giardia-trph.jpg
Giardia in Motion • http://www.youtube.com/watch?v=j1sOJUw5Eo0 • http://www.youtube.com/watch?v=-yIHkq9R5_c&feature=endscreen&NR=1
Coccidia Quick Facts • Causes: • Diarrhea • Hemorrhagic enteritis • Poor growth • Occurs during very stressful events (ie weening)
Parasites • Lab today will be examining fecal slides and identifying which parasites are present • You will • Make a fecal cytology • Sparse stained fecal prep (Campylobacter and Clostridia like organisms • Make a fresh prep • This would allow you to see motile Giardia • Make a fecal float • This will allow you to see ova and cysts