SA derm Flashcards
when looking for parasites down the LM what does the iris diaphragm do?
alter the appearance. if closed - more dark and ‘contrasty’ if open paler
name the 2 cat flea identifiable combs
genal comb - on head/’nose’
pronotal comb - 1st thoracic segment
name 2 lice of the dog (one biting, one chewing) and a cat louse
dog
- biting = trichodectes canis
- chewing - linognathus setosus
cat
- biting = felicola subrostratus
how many legs do fleas and lice have
6
how many legs do mites have. which mite only has 6?
8
trombicula
which mites have long legs
surface dwellers (otodectes, cheyletiella, trombicula)
what do most mite eggs look like, except demodex canis
oval
d. canis = lemon
what is characterisitic about louse eggs
attached to hairs + operculum
what 4 tests are used for ectoparasite finding
collect the scale - flea comb, tape, light scrape
direct smear
skin scrape
hair pluck
what might you find on scale exaination
felicola subrostrata trichodectes canis linognathus spp cheyletiella lice eggs
what ectoparasites might you see on a smear
otodectes (if in the ear..)
or demodex from any ruptured pustule
what mite are you looking for with a trichogram
demodex
what else can a trichogram show you
what stage hair is at
- anagen (growing), fat bulb
- telogen (resting) - tapered bulb
why is liquid paraffin used for mite, lice, etc prep and collection
mites stay alive
tolerated on skin
why would KOH be used instead of paraffin
to visualise better, but kills mites
desc how to do both a superficial scrap and a deep one
superficial - from lesions no oozing. put paraffin/KOH on skin, scrape and more oil/KOH on slide
deep - squeeze skin and add oil/KOH, +++ scrapes from new lesions, until capillary ooze
are sarcoptes ELISA results reliable
not really. false -ves early in dz and false + in atopic dogs
name 4 cytology tests
tape
cotton smear
impression smear
FNA
when should you culture a sample
if you see rods degenerative PMNs of dont find any bacteria recurring in fection all deep infections
culture samples are swabs and biopsies. what areas are they each best at getting samples from
swabs - intact lesions, ears, sinus
biopsy - deep inf, acral lick, discharging lesions
what does wood’s lambs and DTM test for
dermatophytes
what are the pros/cons with dermatophyte culture
dont ID spp
contami/infection
cheap, easy, reliable
what are the different biopsy tech
punch
tru cut
wedge
sx
what conditions do WHWT commonly suffer fro
atopic derm
malassezia derm
demodecosis
ichthyosis
why do sertoli cell tumours cause alopecia
oestrogenising effects/lack of testosterone
why would color of dog skin matter with SCC
often UV-induced –> depig skin, white coat or alopecic areas +++
sponaneous forms are oral or ungual
what is a good way of assessing ‘itchiness’ from owners
visual analogue score - 1–> 10. as in 1 - never
10 - keeps you up at nght, dog not sleeping
describing skin lesions, you need what elements
- distrubution (focal)
- description - 1ry or 2ry lesion (alopecia)
- location (cd-d rump)
- evolution (eg papules –> crusts)
how can you assess whether cutaeneous haem of erythemia
press slide on it - if blanches = erythema (blood in vessels)
desc where fleas, cheyletiella and sarcoptic mange nfection usually occur
fleas = dorsal lumbar/L-S and inner thigh cheyletiella= dorsal back sarcoptes = ventral thorax/abdo and eyes and ears
what information can be acq from a hair examination
color, textures changes
stage of grwoth - telogen easily pulled out
broken?
follicular casts (demodex, pyoderma, malassezia)
what are the main 4 ddx of pruritis
para
inf
hypersens/allergy
misc
what is the pathogenesis of flea infestations
Fe-def in young animals anaemia FAD IH for diplydium caninum transmit bartonella
what are the 1ry signs of FAD
pruritits, papules, erythema
how long from first blood meal until mating and eggs laid from fleas
24 hrs
descr a basic flea life cycle
adults on host 1 wk eggs in eviron (R) - 10d larvae feed on environ/flea poo 2-3wks pupate (R+) 1wk-100d later = adults
desc a basic flea control protocol
both environ + animal = adulticide + IGR
adulticides: fipronil, selamectin, imidacloprid, fluralaner
IGRs:methoprene (makes frontline combo) and lufenurun (program)
house - permethrins
how do you tx FAD - if it tkes 3-4mths to rid fleas from a household
tx as above
wash - to rid of saliva
use program in future to prevent
name the feline demodex
d. gatoi (superficial) or d. cati
desc basic lifecycle for mites
adults on host eggs on hair or in burrow (R) larvae nymphs 2-6wks
what are the signs of sarcoptes
pruritis, crusts, scale, 2ry alopecia,
what are the sign of cheyletiella
trunk scale and erythema and scale
name 2 ear mites which cause waxy discharge
otodectes canis
psoroptes
what are the signs of suckng lice, linognathus setosus
pruritis and ill thrift - rare tho
what are the signs of biting lice, trichodectes and felicola
pruritis, scaling, poor coat qual
can fipronil be used in rabbits
no
what is fipronil licensed for
fleas, tick, lice and cheyletiella mites and harvest mites
imidacloprmid is only licesed for fleas and lice in rabbits - how do you tx mite and tick infections
if with MOX (=advocate)
what para tx are toxic to cats
permethrin
amitraz
~IVM
whats the best way to treat demodex in cats
lime sulfur baths
how do you tx trombicula
fiprinol spray
what endoparasites might cause pododermatitis and what tx
uncinaria stenophala
fenbendazole
what are common causes of bacteria pyoderma
staph pseudointermedius
s aurea, s hyicus
what are the classifications of pyoderma
surface - epidermis, more accurate descr = overgrowth
superficial folliculitis = epid with follicles
deep folliculitis and furunculosis = epid, follicles, dermis and s/c fat
what are ‘hot spots’
pyotraumatic derm
flat moist erosions with erythematous outline
what is the proper word for skin fold pyoderma
intertrigo
what does BOGS stand for
bact overgrowth syndrome - result of underlying atopic derm
most superficial pyoderms are 2ry, name the common 1ry causes
allergy
ectopara
infections
immune suppression
what are the signs of superficial pyoderma
macules, papules, pustul, hyperpig, erosions
what are the signs of deep pyoderma
systemic illness - fever, lymphadenopathy
pyogranulomatous inflm
s. pseudintermedius or psedomonas
sinus tracts, haem+ bullae
what ar the signs of malassezia inflm and tx
always 2ry as normally commensal
ear, v neck, paws, axilla, groin
greasy, erythema, otitis
tx- chlorhex and miconazole shampoo
what is the pathogenesis of canine AD (atopic derm)
defective cutaenous barrier
microbial colonisation
hypersensitivity to food/enviro allergens
when do most dogs develop AD
what are the clinical signs of cAD
pruritis - 1r sign! erythema, saliva stains, papules hot spots/acra lick alopecia, scaling, hyperpigmentation furunculosis or interdigital abscess
is cAD respon to gcorticoids?
y!
how do you ID food allergy
diet trial - home or commercial need 6wks.
or hydrolysed diet - less allergenic. then if signs stopped –> back on old diet, if start again, back to trial
what causes contact derm
sensitisation to norm,
what neoplasm appears like derm
cutaenous lymphoma
what does CARF stand for
cutaneous adv reaction to food
what is the basic approach to pruritis cases
ID para, tx 2ry infections, exclude with trials - for food, fleas or mange.
if suspect AD –> labs for inc IgE
management - of cAD
improve barrier fct -
ID + control flare factors (food, para, environ)
immunotherapy - to desensitise (ASIT)
anti-inflm drugs
tx of cAD
est-FAs,
topical emollients, vitE (anti-oxid), antimicrobials,
c-steroids (flare busters)
— to help barrier and reduce pruritis
how can steroids be used in a safer way
lowest tx dose
no sudden changes
in combo with ‘steroid sparing’ tx eg anti-histamines
seasonal - when worsens
what common medication is given for AD
cyclosporin (atopica)
- delayed response, GE common SE
protopic (tacrolimus)
- less SE, not licensed tho
aclactinib (apoquel)
- JAK inhib so reduces inflm cytokine, not for small digs
name some cyclosporin drug interactions
inhibit metab - azoles, metaclopramide
inc metab - rifampin, phenobarb
IVM inc adverse signs
are anti-histamines used
yes, variable reponse. not licensed. use with EFAs and gcort
chlorphenamine
what are the classifications of alopecia
- self induced
- spontaneous
- inflm (non-symmet)
- non-inflm (symmet)
how does ‘partial’ alopecia appear
thinning of hair in area, not hypotrichosis though (thats congenital)
what 2 major types of demodex are there?
long bodied - d. canis and cati (follicles)
short bodied - d. gatoi (superficial)
what are the 2 clinical syndromes of canine demidecosis
juvenile - generalised and localised forms.
adult - either continuation of juvenile generalised form or onset due to underlying immunosuppressive process
what is the best tx for demodecosis
amitraz (not cats or Chihuahua)
fluralaner (bravecto, new)
when can tx for demidecosis stop
3 x neg skin scrapes over 3wks min
name a common cause of canine dermatophytosis
microsporum canis
how is dematophytosis dx
wood lamp - 50% usually fluoresce green
trichography - arthrospores around shaft look like bubbles
dermatophyte test medium (DTM) - yellow –> red = pos
what is the best tx of dermatophytosis
itraconazole
or topical miconazole + chlorehxadine shampoo
name 2 immune mediated forms of alopecia and briefly desc
dermatomyositis - collies skin and muscle. signs = myositis and alopecia, erythema, crusting. tx = predn
alopecia areata - lymphocytic attack on hair bulb - bsy dx.
name some causes of hair cycle arrest
injection and post-clipping endocrinopathies (HAC, hypothyr, hyperoestro) alopecia x telogen defluxation feline paraneoplastic alopecia
what is injection alopecia
follicular atrophy susp from act of steroid inj and vasculitis from inj
what are the general signs of an endocrinopathy-induced alopecia
- symmetri, bilat, non-infla
- dull, dry, faded
- fails to regrow after clipping
- hyperpigmentation
- scaling + or ++
- easily bruised and por healing
what is alopecia X
in plush coated dogs, juvenile onset loss of 1ry hairs –> retain puppy coat –> complete alopecia of the trunk only
what is telogen defluxaion
following from systemic dz etc the hairs ‘rested’ so when new hairs begni to grow, they push all the telogen hairs out = alopecia after the event (chemo)
what is feline paraneoplastic alopecia
assoc with panc/bile duct carcinoma
ventral abdo and limb alopecia which is smooth, shiny and translucent!
what breeds get post-clipping alopecia
arctic. v long telogen phase, hence the blowing..
are congenital alpecia norm
yes in some breeds.. still predisp to inf
what is pattern baldness and is it an issue
no its not. dont know why but alopecia in certain areas (vary / breed)
desc follicular dysplasia
normal puppy coat –> breaks and lost –> scaling and 2ry inf
regrowth = weird
what is cyclical flank alopecia
as it says,.. seasonal alopecia. no idea wy - try melatonin when unsure if needs be
what is effluvium
anagen defluxion. systemic illnesses.
what is sebaceous adenitis
predis = viszla, poodles, samoyeds
lymphocytic inflm directed at seb glands. signs - MF alopecia, ‘frond-like’ scales, 2ry bact inf
what tx for scaling ++
keratolytic shampoo + moisturising
essential FA suppl
tx 2ry bacterial inf
what are the signs of cutaenous epitheliotropic lymphoma
diffuse alopecia, erythema, scaling, ulcers, plaques +- prurits
what is traction alopecia
from rubbing - pos collar
name the 4 main feline reaction patterns
- self induced
- head and neck - v pruritic
- miliary - papular crusts
- eosinphillic granuloma complex
what are the causes and signs of self induced alopecia in cats
- pruritis –> over grooming, but will be symmetrical as cats are thorough
- restricted to the sites the cat can reach
- furballs, fur in mouth/teeth
whats might cause head and neck pruritis
otodectes cyanosis
neotrombicula
bacteria
oro-facial pain syndrome in burmese cats
what causes miliary dermatits
otodectes cyanosis
neotrombicula
bacterial
dermatophytosis
what is the eosinophic granuloma complex
- eosinophilic plaques
- eosino granuloma
- eosinophillic (indolent) ulcer
seen in allergic skin condition and assoc with overgrooming
what are the eosinophillic plaques
- raised alopecic plaques (pruritic), ventral body.
what are the eosinophillic granulomas
at different areas, young get = linear, non ulcerated ones. other get = proliferative oral ones - pruritic i 2ry infection too
can spontaneously regress.
what are eosinophilic ulcers/indolent
erythematous ulcer on upper lip
