Diagnostic Procedures Flashcards
why do we need flea combs?
- cats are able to lick 90% of adult fleas off, so need the fine toothed comb to find the rest!!
-PLUS a white piece of paper, add water, let site for a few minutes and if see red/brown streaks = flea shit
-might be only evidence of flea infestation on an adult cat!!
describe trichogram
looking at hair under a microscope
pluck some hair with fingers or tweezers
blunt hair tips indicate trauma to hair (overgrooming/licking)
hair follicle mites: cigar shaped with 4 pairs of very short legs, sometimes get pulled out with hair at roots
middle of shaft: if look disassembled, could be infected by a dermatophyte (invades hair and changes structure)
describe wood’s lamp
UV light with cobalt filter
screening tool for dermatophytosis
-sensitivity ranges from 50-80% regarding microsporum canis
-some dermatophytes do not produce fluorescein substances at all tho so a negative result does NOT rule out dermatophytes
great tool if positive, but doesn’t say much if negative (positive = glows apple green and follows hair shafts)
describe skin scrape
need:
-10 blade, dulled
-mineral oil (1 drop on glass slide, dip blade in oil to hold sample on blade)
how to:
-scrape with rounded part of blade, perpendicular to blade to avoid pain and actually get a good sample
-scrape quickly because uncomfortable for patient
-put on slide and thin sample out
-put a cover slide on (to help you flatten out sample and see better)
-deep skin scrape: hair follicle depth, for demodex; squeeze skin in attempt to squeeze mites higher up, want to make skin bleed
-superficial scrape: wider area, don’t attempt to make skin bleed
describe skin cytology
the MOST common diagnostic on the clinic floor
-prefer intact lesions if possible/available = less interference from outside skin microbiome
many methods:
-direct push presses onto the slide
-CLEAR scotch tape if hard to access area with slide
staining is different for glass versus scotch tape!
-scotch tape NEVER goes into fixative (1st blue stain, bc will eat the tape)
-can see neutrophils, bacteria, etc.
describe otoscopy
should be done prior to ear cytology
-bring ear out, not up
should be able to see
-pars flaccida: dorsal
-pars tensa: ventral
-handle/stria of malleus
describe ear cytology
bring ear flap UP (not out like in otoscopy)
go in, press against lateral wall, and then come out
-animal is not sedated so NOT trying to get close to ear drum because patient could move and cause you to rupture ear drum
-make sure you know/indicate what swab from what ear (crack the left swab, etc.)
-rub swab on slide 10-20x to thin out enough so no clumps
-not necessary to heat fix
-can see yeast, bacteria, neutrophils, etc.
describe skin biopsy
try to write a story for the pathologist to show the evolution of the skin lesions
-send a few different degrees of severity if exist
-take a sharpie and mark the areas to be biopsied
-prepare cassettes (1-4) and write on EACH WHERE CAME FROM
-go big or go home, bigger is better in terms of sample size! (according to pathologist) but PLEASE adjust based on patient size and location
-biopsy sites are not clipped, scrubbed, or anything; do not want to remove anything that could be diagnostic (regular biopsies are DIRTY; ON EXAM ACCORDING TO AUSTELL)
-turn only in one direction, no shearing, grab sample with forceps, level, and cut off then suture the hole closed (no forceps, not too close to margin)
