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211 Cards in this Set
- Front
- Back
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list the 4 dermatological patterns the pruritic cat may present with
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1. miliary dermatitis
2. non inflammatory alopecia 3. eosinophilic dermatoses 4. face and neck erosion |
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what are likely causes of pruritis in a cat < 6 months?
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- parasitic dermatoses i.e. Notoedres or Cheyletiellosis
- dermatophytosis - FAD |
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what are likely causes of pruritus in a cat between 8 months and 3 yrs old?
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allergic dermatitis: adverse food reaction, atopy
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in an older cat a pruritic exfoliative erythroderma may suggest...
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cutaneous epitheliotrophic lymphoma
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in cats, which causes of pruritis are usually steroid responsive?
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allergies: FAD, early AFR and atopic
usually partially or poorly responsive in chronic AFR and behavioural disorders |
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what are the most common ddx for a cat with miliary dermatitis?
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allergies, ectoparasites and infections
immune mediated diseases such as pemphigous may occasionally mimic a mild dermatitis |
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negative superficial skin scrapings do not rule out presence of which mites?
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- Sarcoptes
- Cheyletiella - Otodectes cynotis |
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describe the trichogram technique
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- grasp individual hair with haemostat forceps and pluck hair completely (approximately 20)
- lay hair on microscope slide (with mineral oil) with hair oriented in the same directin - examine hairs at low power for morphology, concentrating on hair bulb, shaft and pigmentation want to determine how many hairs are in telogen (resting) vs anagen (growing) phase in shedding or suspected endocrine problems |
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interpretation of trichograms
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- anagen phase bulbs are rounded, smooth, shiny, glistening and soft so the root may bend
- telogen bulbs are club or spear shaped with a rough surface - sample with exclusively or mostly telogen hairs indicates endocrinopathy or follicular arrest - also to determine if alopecia is self inflicted secondary to rubbing or licking - if animal is pruritic and licks the hair off the tips of the hairs are broken off - any trauma to the hair shaft such as occurs in dermatophytosis or anagen deflation, may also cause broken ends - if hair falls out for other reasons the tips are tapered |
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a positive Wood's lamp examination is diagnostic for dermatophytosis. true or false?
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false, positive Woods lamp is only suggestive of dermatophytosis not diagnostic. needs to be confirmed with fungal culture.
a negative Woods lamp is inconclusive |
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any pruritic, scaly, odourous or alopecic animal should be evaluated for evidence of ____________ or ____________ infection
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bacterial or yeast
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list different methods to obtain cytological samples
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- aspirations
- impression smears - ear swabs - tape preparations |
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when would we use impression smear ?
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when skin is greasy or exudative
ulcers, cut surface of nodules, and tumours and the surface of 'pricked' papules, pustules and vesicles may also be sampled his way |
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when are bacterial and fungal cultures indicated
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- bacterial when pyoderma or otitis not responding to antibiotics or when rods are identified
- fungal to determine dermatophytosis - patients with nodular lesions, draining tracts, non-healing wounds, recurrent cat bite abscesses, deep pyoderma and cellulitis |
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list indications for skin biopsies
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1. a skin condition that appears unusual or serious
2. a skin problem that is not responding to therapy 3. persistent erosions or ulcers 4. persistent draining tracts 5. persistent nodules 6. suspected neoplastic lesions 7. suspected auto-immune diseases |
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where should biopsies be obtained for macules, papules and pustules?
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from a number of primary lesions
the lesion should be centred in the middle of the biopsy specimen |
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always take a biopsy from the middle of an ulcer. true or false?
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false. taking a biopsy from the middle of an ulcer is rarely beneficial
collect multiple biopsies from the junctions between ulcerated and normal skin, this allows the pathologist to see the process leading to ulceration |
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what kind of biopsies are needed to investigate draining tracts?
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deep biopsies, as the pathological changes are usually in the dermis or subcutis
punches may not be adequate for this purpose, so ellipse or wedge biopsies should be obtained using a scalpel blade samples can be submitted for histopath as well as culture |
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where do we biopsy for areas of haemorrhage?
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areas of haemorrhage expand out from vascular lesions and should be biopsied centrally. vasculitis or vasculopathy may affect the deep dermal or pannicular vessels only it is important that the deep portion of a punch biopsy be retained in the sample
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when is aseptic preparation of the skin surface for a skin biopsy indicated?
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1. when the whole lumps are being resected
2. when the tissue sections are being submitted for bacterial and fungal culture |
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collect a minimum of __ punch biopsies for each case
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5
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for a pruritic dog what are the first 3 possibilities to rule out?
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1. ectoparasites (superficial skin scraping)
2. infection (cytology, woods lamp, fungal culture) 3. flea and food allergy |
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age of onset for sarcoptes scabei canis?
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any
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what do we use for an acaricidal trial?
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selamectin (revolution) at 6mg/kg for 3 treatments at 2 week intervals
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what is the age of onset for FAD (flea allergy dermatitis)?
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3-5 years, uncommon in dogs < 6months
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describe distinguishing features of the distribution of FAD
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- symmetric pattern dorsal lumbosacral area, caudomedial thighs, ventral abdomen and flanks
- NO otitis externa - NO face or pedal involvement |
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how do we do a FAD trial?
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> Nitenpyram (Capstar) 1mg/kg daily for 30days
> Spinosad (Comfortis) 30mg/kg every 14 days (?)) as a general rule the response or lack of to the trial is assessed on day 28 |
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which dog breeds are overrepresented with having food allergies?
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labs, WHWT, german shepherds, spaniels
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how do we diagnose food allergy dermatitis?
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- feed a novel hoe prepared protein and carbohydate or commercial hydrolysate diet for 6 weeks
- home prepared diet is the gold standard - demonstrate that clinical signs recur when feeding a test meal of the dog's previous diet --> most dogs relapse in 24-72hrs do a sequential rechallenge with multiple food sources contained in the original diet reported to cause AFR in dogs (beef, dairy, wheat, soy, chicken, lamb, eggs( - to determine exactly which food source causes the allergy - then select a commercial food that does not contain the offending substance |
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which dog breeds are predisposed to atopic dermatitis?
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golden retrievers, labs, terriers, dalmations and shar peis, german shepherds, rottweilers, bull terriers, WHWT, boxers
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age of onset of atopic dermatitis?
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12-18 months, with 95% of dogs first showing clinical signs at <5yo
exotic breeds such as akita, sharpei an chow chow may show signs as early as 6 months |
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pruritis in cat <6 months old would suggest..
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either
1. parasitic dermatoses i.e Notoedres, Cheyletiellosis, 2. dermatophytosis 3. FAD |
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pruritis in a cat 18months - 3 yrs would suggest...
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- allergic dermatitis- AFR or atopy
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what are the 4 main types of reaction patterns in pruritic cats?
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1. miliary dermatitis
2. non inflammatory alopecia 3. eosinophilic dermatoses 4. face and neck erosion |
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how do we biopsy for lumps and nodules?
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excisional biopsy of the whole lump plus normal margins is the preferred technique
should only be perfomed after FNA has ruled out mast cell neoplasia |
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what are common causes of dermatitis in young animals?
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- parasites such as Demodex canis, Otodectes cynotis or Sarcoptes scabei
- bacterial infections - dermatophytosis |
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atopy is common in dogs 6 months and younger. true or false?
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false. atopy is rare in animals under 6 months
food and flea allergy can effect dogs under 1 yr |
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why is it important to determine the severity of the pruritus?
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1. because some diseases are only mildly pruritic i.e. demodicosis, dermatophytosis whereas others are severely pruritic i.e. canine scabies and feline eosinophilic plaque
2. the level of pruritis at the initial presentation is used as a starting point to monitor the response to treatment |
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pyoderma is usually secondary to...
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atopic dermatitis, AFR or hormonal disease
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what organisms are detected by superficial skin scrapings?
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Sarcoptes, Notoedres cati, Cheyletiella spp, Dermanyssus gallinae, Otodectes cynotis and Demodex gatoi
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what organisms are detected by deep skin scrapings?
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Demodex cati and Demodex canis
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a finding of one mite or egg is diagnostic for which mite species?
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- Sarcoptes (if dont find any cant rule out)
- Cheyletiella - Notoedres cati - Otodectes cynotis |
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negative skin scrapings do not rule out the presence of
___________ ___________ ___________ |
- Sarcoptes
- Cheyletiella - Otodectes cynotis |
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describe interpretation of trichograms
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- to determine how many hairs are in telogen (resting) phase vs anagen (growing) phase in shedding or suspected endocrine problems
- anagen-phase bulbs are rounded, smooth, shiny, glistening and soft so the root may bend - telogen bulbs are club or spear shaped with a rough surface - a sample with exclusively or mostly telogen hairs points to an endocrine disorder or follicular arrest - if the animal is pruritic and licks the hair off the tips of the hairs are broken off - any trauma to the hair shaft such as in dermatophytosis or anagen defluxion may also cause hair with broken ends - if the hair falls out for other reasons the tips are tapered |
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a negative result ear smear is ____________
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inconclusive
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list different techniques to obtain cytologic samples
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1. impression smears
2. ear swabs 3. aspirations 4. tape preparations |
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what skin lesions is FNAB useful for?
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pustules, cysts, vesicles, abscesses and nodules
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what are indications for bacterial and fungal culture?
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- nodular lesions, draining tracts, non-healing wounds, recurrent cat bite abscesses, deep pyoderma and cellulitis
(not responding to antibiotic therapy or rods) |
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indications to perform skin biopsy?
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- skin condition that appears unusual or serious
- a skin problem that is not responding to therapy - persistent erosions or ulcers - persistent draining tracts - persistent nodules - suspected neoplastic lesions - suspected auto-immune diseases |
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how do we biopsy macules, papules and pustules?
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punch biopsies should be obtained from a number of primary lesions
the lesion should be centred in the middle of the biopsy specimen |
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how do we biopsy ulcers?
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collect multiple biopsies from junctions between ulcerated and normal skin , this allows the pathologist to see the process leading to ulceration
alternatively a whole ulcer including a rim of normal skin can be submitted |
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how do we biopsy draining tracts?
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- deep biopsies are required as the pathological changes are usually in the dermis or subcutis
- punches may not be adequate for this purpose so ellipse or wedge biopsies should be obtained using a scalpel blade - samples can be submitted for histopath as well as culture |
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what are the two indications to aseptically prepare the skin for biopsy?
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1. when whole lumps are being resected
2. when tissue sections are being submitted for bacterial and fungal culture |
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what are the easiest and most valuable tests to perform when first presented with the itchy dog?
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skin scrapings and skin and ear cytology
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how do we do an acaricidal trial?
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selamectin (Revolution) at 6mg/kg for 3 treatments - 1 treatment every 2 weeks
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which dog breeds are predisposed to yeast infection?
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WHWT, silky & australian terrior, chihuahua, poodles, GSD, cocker spaniels
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FAD has a seasonal or non-seasonal pattern?
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seasonal
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age of onset for FAD?
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3-5yrs, uncommon in dogs < 6 months
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describe distribution of FAD
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- symmetrical pattern dorsal lumbosacral area, caudomedial thighs, ventral abdomen and flanks
- no otitis externa - no face or pedal involvement |
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an eosinophilic papule without bacteria on a dog is suggestive of_____________
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flea allergy dermatitis
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how do we do a flea allergy trial?
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- nitenpyram (Capstar) 1mg/kg PO q24h x 30d
- Spinosad (Comfortis) 30mg/kg PO q14d |
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which dog breeds are over-represented for food allergy?
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- labs, GSD, WHWT and spaniels
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what is the age of onset for AFR in dogs?
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wide age range: 2-14y
50% have onset <1 yo |
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how do we diagnose AFR?
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- feed a novel home made protein and carbohydrate diet for 6 weeks
- demonstrate that clinical signs recur when feeding a test meal of the previous diet- most dogs relapse within 24-72h - do a sequential challenge with multiple food sources that were contained in the original diet reported to cause AFR in dogs (i.e. beef, dairy, wheat, soy, chicken, lamb, eggs) - (Tx:) select a commercial food that does not contain the offending substance |
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what is the age of onset for atopic dermatitis?
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12-18 months old with 95% of dogs first showing clinical signs <5 yo
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bilateral conjunctivitis and rhinitis may be associated with ________________
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atopic dermatitis
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behavioural self induced alopecia is more common in which breeds?
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siamese, abyssinian, burmese
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what are the major differentials for pruritis in a cat
< 6 months |
- parasitic dermatoses i.e. Notoedres, Cheyletiellosis
- dermatophytosis - FAD |
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what are the major differentials for a pruritic cat
8 months - 3yrs |
an allergic dermatitis i.e. FAD or atopy
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in an older cat a pruritic exfoliative erythroderma may suggest...
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cutaneous epitheliotrophic lymphoma
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in cats the response to corticoids is usually good for
1____________ 2_____________ 3____________ |
1. FAD
2. atopy 3, acute AFR |
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how can we look for mites on cats?
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- coat combing
- skin scrapings - ear smear ** acaricidal trial (negative only rulls out Notoedres) |
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what mites do we detect with superficial skin scraping on cats?
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- Notoedres cati
- Sarcoptes scabei (can hide) - Cheyletiella (may be zoonotic) - Otodectes cynotis - Demodex gatoi |
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what mites do we detect with deep skin scraping on cats?
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- Demodex cati
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an acaricidal trial will kill all mites including demodex. true or false?
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false. all except demodex
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age of onset for FAD in cats
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young cats > 6 months
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compare age of onset for FAD in dogs and cats
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dogs: 3-5yrs , rarely < 6 months
cats: young > 6months |
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what do we use for flea allergy trial in cats?
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nitenpyram (Capstar) @ 1mg/kg PO q24h or 48h for 30d
assess response or lack of at day 30 |
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compare age of onset of AFR in dogs and cats
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dogs: 50% <1yo
cats: any age |
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age of onset of atopic dermatitis in cats?
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6 months to 3 yrs
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compare age of onset of atopy in dogs and cats
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dogs: 12-18 months with 95% < 5yo
cats: 6 months to 3 yrs |
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what signs may be seen concurrently in cats with atopic dermatitis?
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- concurrent ceruminous otitis
- concurrent blepharoconjunctivitis, sneezing, rhinitis, cough |
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what is alopecia in the dog and cat most commonly associated with?
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pruritis due to allergic skin disease
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what are typical inflammatory causes of non-traumatic alopecia in dogs?
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- bacterial folliculitis
- dermatophytosis - demodicosis - sebaceous adenitis |
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what are causes of non-inflammatory alopecia in dogs?
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- abnormal hair growth (follicular dystrophies or dysplasia)
- hair cycle abnormalities (endocrine) |
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what are the top 3 Ddx for inflammatory non pruritic alopecia in dogs?
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1. demodex
2. bacterial pyoderma 3. dermatophytosis |
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describe any canine breed predispositions to alopecic skin disorders
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- dobermans & colour dilution alopecia
- alopecia X common in plush coated dogs i.e. pomeranian, samoyeds, akitas |
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what diagnostic tests do we perform for a dog with inflammatory, patchy, focal to multifocal alopecia?
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1. Woods lamp and fungal culture for dermatophytes
2. deep skin scraping for Demodex canis 3. trichogram for dermatophytes and Demodex 4. express papule and directly apply to microscope slide, stain with diff quick if expression of papule does not produce any material then use back of scalpel blade scrape top of papule firmly and smear contents- examine with oil immersion lens, determine predominant inflammatory cell type and number and type of bacteria/yeast ** if negative for these or positive + treated and alopecia persists then do skin biopsy |
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what diagnostic test(s) do we perform for non-inflammatory, non pruritic, diffuse symmetric alopecia?
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1. biopsy
2. whenever an "endocrine pattern" is present or there is uncertainty do (minimum) CBC, biochem panel and UA +/- specific tests for endocrinopathies such as hyperA and hypoTh |
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which breeds are predisposed to alopecia X?
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poodle and nordic and plush coated breeds i.e. pomeranian, samoyed, chow chow
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where do we biopsy dogs with (non pruritic) alopecia?
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1. area of most advanced hair loaa
2. transitional or mildly affected skin and hair coat 3. normal region 4. skin with different coloured or textured hair |
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it is always safe to assume the alopecic cat is pruritic until proven wrong. true or false?
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true (usu self induced)
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what can be indirect evidence that a cat's alopecia is self induced and not spontaneous?
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- vomiting hairballs
- hair in faeces - tufts of hair in cat's hiding areas - hair in teeth - trichograms revealing broken distal ends of hair |
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what steps do we take if history and PE indicate that the cat's alopecia is spontaneous?
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- check for drugs, illness (severe illness, pregnancy), major surgery etc
- skin scrapings to rule out demodex - woods lamp & fungal culture for dermatophytes - CBC, serum biochem, total T4, FIV and FeLV testing and urinalysis +/- histopath of skin biopsy may be supportive of dx of hyperadrenocorticism, paraneoplastic |
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what are the ddx for non-pruritic alopecia in cats?
|
inflammatory:
- demodicosis - dermatophytosis non inflammatory: follicular dysplasia - congenital hypotrichosis hair cycle arrest: endocrine - hyperA - hypoTh - diabetes mellitus |
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disorders associated with scaling are commonly referred to as _______________
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seborrhoea
(disorders of cornification) |
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regarding disorders of cornification, primary disorders are much less prevalent and it is prudent to regard the problem as secondary until proved otherwise. true or false?
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true
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How do we work up for scaling in absence of pruritus?
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- demodex and dermatophytes often cause scaling (deep skin scraping, woods lamp + fungal culture)
- check diet for low fat - check shampoo regimes (excessive bathing with drying shampoo) - evaluate for endocrinopathy: hypothyroid (heat seaking, lethargy, weight gain), hyperA, alopecia X - evaluate for metabolic disease: hepatocutaneous syndrome - evaluate for autoimmune disease: pemphigus, CLE - evaluate for neoplasia: epitheliotrophic lymphoma, thymoma assoc exfoliative dermatosis - consider a primary cornifcation disorder: skin biopsy for histopath |
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a 12yo dachshund presents with scaling as the predominant problem. he is not itchy. what diagnostic tests do you perform?
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1. deep skin scraping (demodex)
2. Wood's lamp and fungal culture (dermatophytes) 3. total T4 (hypothyroid) 4. LDDT (hyperA) also: - palpate testicles (hyperoestrogen, paraneoplastic syndrome) - evaluate amount of fat in diet - consider bathing regimens - consider autoimmune disease (biopsy may support) - if all secondary causes ruled out consider primary scaling disorder and do a biopsy |
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the presence of erosions suggests disease processes where?
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centred on the epithelium or the dermal-epidermal interface
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erosions involve the dermis and epidermis. true or false?
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false, erosions do not involve the dermis
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ulcers are usually secondary to disease processes where?
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centred in the dermis or subcutaneous tissues or submucosa, but ulcers may also be self inflicted if the condition is pruritic
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describe distribution pattern of autoimmune diseases such as CLE
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face, ears and feet
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for ulcers, cytological examination of any exudate and surface impression smears is mandatory. true or false?
|
true
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in pemphigus complex where does acantholysis occur?
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acantholysis is restricted to the area where the specific desmoglein is present
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describe age of onset of pemphigus in dogs
|
- usually a middle age disease, average age is 4yo with 75% of dogs developing lesions at or before 5yo
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common sites for pemphigus lesions
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lesions start on the face: most commonly bridge of nose and planum nasale, other facial areas include dorsal muzzle, periocular area and the pinnae. nasal depigmentation is very common and may result in photodermatitis
may have involvement of footpads and genitals |
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what are the most common causes of traumatic alopecia in dogs?
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- allergies
- pruritic pyoderma - Malassezia dermatitis |
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failure of hair growth after clipping (in a dog) is suggestive of...
|
hypothyroidism, hyperadrenocorticism or alopecia X
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what are important factors to consider for a dog with non inflammatory alopecia?
|
- breed
- age of onset - sterilisation status - colour of affected hair coat - other cutaneous and systemic clinical signs |
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skin biopsy is a useful diagnostic tool for diagnosing endocrinopathies. true or false?
|
false. A minimum CBC, biochem, urinalysis and total T4 should be performed in dogs if endocrinopathy is suspected
specific testing for hypoT and hyperA may be indicated |
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what are follicular dystrophies?
|
abnormalities in the development of hair characterised by abnormal hair shafts and/or hair follicle malformation resulting in altered coat quality and alopecia. Causes a symmetrical alopecia often associated with hyperpigmentation
> colour dilutant alopecia > black hair follicular dystrophy > breed related follicular dystrophies |
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describe histologic changes characteristic of alopecia X in dogs
|
- orthokeratosis and telogen phase hair follicles
- "flame follicles"- telogen phase follicles with excessive trichilemmal keratinisation - in chow chows and malamutes there are abundant flame follicles - in pomeranians there is mminiaturisation of the hair follicles with flame follicles rare or absent |
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almost any inflammatory skin disease can lead to secondary scaling. true or false?
|
true
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what things do we evaluate for for dogs with scaling without pruritus
|
- demodex (deep skin scrape)
- dermatophytes (woods lamp and fungal culture) - evaluate diet (low fat) and bathing regimes (drying shampoo) - evaluate for endocrinopathy (CBC, biochem, U/A, TT4, LDDT) - evaluate for metabolic disease (bloods) - evaluate for immune mediated disease i.e. pemphigus, CLE - evaluate for neoplasia i.e. epitheliotrophic lymphoma or thymoma associated exfoliative dermatoses - if all of these are negative consider primary scaling disorder |
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how can erosions occur?
|
erosions may be the result of external forces (i.e. excoriation), necrosis or inflammation causing destruction or exfoliation of epithelial surface
or may evolve from rupture of pustules, vesicles or bullae |
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describe the diagnostic approach to ulcers and erosions in the non-pruritic dog
|
- superficial and deep skin scrapings and fungal culture if associated with scaling and alopecia
- cytology should be obtained from any vesicular or pustular eruption and cytology of exudate from under crusts may help to see if bacterial infection - for ulcers, cytological examination of any exudate and surface impression smears is mandatory - most diagnostic technique is a skin biopsy for histopath - + tissue biopsy specimens for bacterial and fungal culture +/- CBC, biochem, UA |
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list some aetiological agents of nodules and draining tracts in dogs and cats
|
- Actinomyces
- Mycobacterium - Nocardia (zoonotic) - Cryptococcus - Sporotrichosis (zoonotic?) |
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what are the primary diagnostic tests to perform for a dog or cat with nodules?
|
- cytology
- C & S - biopsy - a minimum data base of CBC, biochem and UA is usually indicated +/- diagnostic imaging |
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ensure to wear glove and aseptically prepare the site prior to taking biopsy for histopathological examination. true or false?
|
false, you should wear gloves (zoonotic potential associated with some nodules) but the site should not be scrubbed or prepared in anyway (may kill micro-organisms). When biopsy taken for culture surgical prep should be performed.
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ensure to aseptically prepare the site prior to taking a biopsy for culture. true or false?
|
true. when biopsies are taken for culture a surgical prep should be performed and the sample collected as aseptically as possible
|
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what are the most important diagnostic steps to take for a dog or cat with nodules/draining tracts?
|
- peform a FNA, impression smear of exudate, tissue imprint or scraping of the margin of the lesion
- collect at least 3 or 4 specimens - collect a skin biopsy for aerobic, anaerobic, mycobacterium and deep fungal culture - ask pathologist for special stains i.e. ZN, PAS, acid fast - collect skin biopsy for histopath - wear gloves |
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a 3 yo MC DSH presents with a non healing wound with discharging fistulae developed after a dog bite. what diagnostic tests do you perform?
|
- impression smear of exudate + FNA (cytology) + deep swab of draining fistula and stain with diff quick and another sample to lab for gram and acid fast stain
- biopsy for histopath - biopsy for culture- look for aerobic, anaerobic, Mycobacterium, fungal ( and give pathologist a list of ddx) |
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in regards to otitis what are predisposing causes
|
predisposing causes do not cause otitis but they increase the risk of getting otitis. These factors need to be recognised and controlled to decrease the frequency of recurrence
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what are the predisposing factors of otitis externa
|
1. conformation
- excessive cartilagenous folds associated with stenosis reduces lumen diameter in conjunction with pinnae tightly folded over external orifice - sharpeis 2. excess hair - excessive hair or knots may occlude external ear canals; impairing ventilation and clearance of normal secretions - poodles, bichons 3. pendulous ears - no difference in temp in external ear canal of normal dogs with pendulous pinnae vs upright pinnae - it is predisposition of these breeds to allergies that accounts for increased relative risk of ear disease, rather than pinnal anatomy - bassets, spaniels 4. excessive moisture - swimming, bathing - can lead to maceration and predispose to infection - in hot humid climates there are more bacterial infections |
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in regards to otitis what are primary cause?
|
primary causes directly induce otitis externa. it is critical that the primary cause is found and either eliminated or controlled
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what is the most common cause of otitis externa?
|
atopic dermatitis
|
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in regards to otitis, what are perpetuating factors?
|
perpetuating factors prevent the resolution of otitis externa and include
- narrowing of the ear canal - ear canal fibrosis and calcification - otitis media they may be a major cause of poor response to therapy |
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Malassezia pachydermatis is a common complication with _______ ________
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allergic otitis
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|
describe the diagnostic approach to otitis externa
|
-external ear canal (both ears) examined for erythema, patency or stenosis, exudate, proliferative changes, ulceration, FB, parasites, tumours. the tympanic membrane should be examined for colour, distension and integrity
- cytology: collect sample from horizontal ear canal of both ears, roll swab onto glass side, Diff Quik - bacterial culture and sensitivity is not routinely performed and is reserved for non-responsive or recurrent cases or when rods are present |
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what radiographic abnormalities may be seen with otitis media?
|
- thickening or lysis of the bulla
- opacity in bulla or lysis ^^ - sclerosis and proliferation of petrous temporal bone |
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|
immature flea stages in the environment represent ___% of the total flea population
|
95%
|
|
|
two active ingredients in frontline plus
|
fipronil and methoprene
|
|
|
how long can flea pupae remain dormant in the environment for?
|
up to 6 months
|
|
|
what are the 4 fundamental steps to an integrated flea control program?
|
1. use an effective residual adulticide to kill adult fleas that jump onto the pet for a period of several weeks
2. use an insect growth regulator to prevent environmental contamination with viable flea eggs 3. mechanical measure to aid reduction of flea biomass by mechanical removal of environmental life stages i.e. washing, vacuuming 4. education of pet owner to maximise compliance and improve management of expectations |
|
|
what is the most common flea found on dogs and cats worldwide?
|
Ctenocephalides felis felis
|
|
|
flea eggs are shed off the coat into the environment within ___hrs of being laid
|
8
|
|
|
match up:
a) adult fleas b) larvae A) positively geotactic and negatively phototactic B) negatively geotactic and positively phototactic C) positively geotactic and positively phototactic D) negatively geotactic and negatively phototactic |
a) adult fleas B) negatively geotactic and positively phototactic
b) larvae A) positively geotactic and negatively phototactic |
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when does flea mating occur on the host?
|
within 8-24hrs with egg production beginning 24-48hrs within first blood meal
|
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what are 2 factors that contribute to reduced flea burdens seen in winter
|
- reduced humidity and reduced temperature
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what is the primary role of IGRs in flea treatment/prevention
|
to halt flea reproduction and reduce future environmental flea populations
|
|
|
why is rapid flea kill important for an adulticide?
|
1. to minimise irritation and discomfort to the animal
2. to ensure the number of adult fleas on a treated animal at any one time remains low and inconspicuous to pet owners 3. to prevent viable egg production an adulticide only product should kill fleas within 24h to prevent viable egg production. Speed of kill is dose dependent and declines over time |
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|
vacuuming will remove ___ of emerged adult fleas
|
95%
and will stimulate pre-emerged adults to emerge |
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|
describe the pupal window factor
|
when giving an adulticide the adult fleas are killed on the pet (in 24-48h?) but newly emerged fleas from the environment can land on the pet during this time. Because adulticides do not kill fleas immediately these newly emerged fleas appear on the coat before they die and this can be confused as product failure by the client
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when gathering a history for flea control what questions should be asked?
|
1. what flea products are you using now (for all pets)?
2. when was the last dose administered for all pets? 3. how many applications have you used when applied for each pet? 4. when were fleas noticed? 5. is this a recurring problem? 6. how many and what other types of pets are in the house (esp import an to determine if ferrets, rabbits, hedgehog)? 7. are fleas a problem on all your pets? 8. how many hours a day does the dog sped outdoors and where does it go? 9. do other pets visit your household or does your pet visit another home? 10. where does your pet sleep or rest? 11. do you have an elevated porch, a crawl space or another structure under which your pet, stray animals or wildlife may get access? 12. are many people bitten by fleas in the home and if so where do you see fleas? |
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in cats with pemphigus foliaceus what are two additional sites (other than face, periocular and pinnal lesions) where lesions are seen?
|
1. nail beds (erythema, swelling, paronychia)
2. perimammary gland |
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what will cytological smears show us for an animal with pemphigus?
|
numerous non-degenerate neutrophils, occasionally numerous eosinophils and numerous acantholytic keratinocytes seen in large clusters or rafts
|
|
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free floating rafts of partially adherent acantholytic cells and adherence of acantholytic cells to overlying stratum corneum are both characteristic histopathological features of _________________________
|
pemphigus foliaceus
|
|
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what is the disease that mimics pemphigus foliaceus in dogs?
|
pustular dermatophytosis.
In this unusual variant of dermatophytosis, Trichtophyton dermatophytes colonise the stratum corneum but not the hair shafts. The dermatophytes elicit neutrophil chemoattraction and lead to subcorneal pustular formation. proteases released by the fungi +/- neutrophils result in marked epidermal acantholysis. Because the fungal hyphae may not be seen with routine H &E stain this fungal infection may be misdiagnosed as PF. hence fungal culture of tissue biopsies is imperitive in cases of suspected PF. |
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where is desmoglein 1 strongly expressed?
|
in superficial keratinocytes of haired skin (and mucous membranes)
|
|
|
what diagnostic tests do we perform for suspected pemphigus?
|
1. cytology- impression smear (acantholytic cells)
2. skin biopsy for histopath and for fungal culture |
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what is furunculosis?
|
hair follicle infection that breaks through the hair follicle. "boils" or "canine acne". deep follicular inflammation leads to follicular rupture releasing hair shaft keratin, bacteria and bacterial products into the dermis resulting in a furunculosis or infection of dermis and subcutis
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what is the most common cause of deep pyoderma?
|
generalised demodecosis
|
|
|
list predisposing causes that may trigger deep pyoderma
|
- generalised demodecosis (most common)
- hyperadrenocorticism - actinic disease - immunologic defects - comedonal diseases such as calluses, actinic comedones and schnauzer comedone syndrome |
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|
haemorrhagic bullae are a distinctive clinical feature of
|
canine deep pyoderma
|
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what is the primary lesion of canine deep pyoderma?
|
haemorrhagic bullae
|
|
|
describe actinic furunculosis
|
a common, solar induced deep bacterial pyoderma occurring more commonly in lightly pigmented sparsely haired dogs i.e. dalmations, whippets, bull terriers etc. Actinic comedones may be present- these are distinctive solar induced comedones that occur in non pigmented lightly haired skin as a consequence of follicular occlusion secondary to dermal fibrosis. Multiple grouped dilated hair follicles that are filled with darkly coloured keratinous or caseous debris. rupture of comedones releases follicular keratin and hair into dermis causing foreign body response that results in a deep furunculosis.
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|
canine acne probably has a genetic predilection. True or false?
|
true
|
|
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how is actinic furunculosis diagnosed?
|
- the differentials include all other causes of bacterial folliculitis and furunculosis
- diagnosis is based on the correlation of breed, coat colour and length, UV exposure and lesion localisation to body sites commonly affected by solar damage - skin biopsy is necessary to confirm actinic furunculosis for histopath - it is recommended to delay skin biopsy until dog has received appropriate systemic antibiotics for at least 3 weeks in order to resolve secondary bacterial pyoderma |
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|
list localised syndromes featuring traumatic furunculosis
|
1. post grooming furunculosis
2. canine acne 3. feline acne 4. callus pyoderma 5. interdigital furunculosis |
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|
describe the lesions associated with canine acne
|
- papules are the initial lesion, these enlarge and form pustules, rupture and form nodules
- nodules may fistulate and drain a seropurulent exudate - fistulous tracts may occur as a sequelae to follicular rupture leading to scarring - distribution- chin and lower lip |
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what are the differentials for canine acne?
|
- localised demodecosis
- dermatophytes - early mild juvenille cellulitis these are easily ruled out |
|
|
the primary change that occurs in cats with acne appears to be ...
|
an alteration in keratinisation process within the hair follicle
|
|
|
what are 3 bacterial spp that have been reported to be involved in feline acne?
|
- Pasteurella multocida
- beta-haemolytic Streptococci - coagulase positive Staphylococcus important to remember this is secondary bacterial complication, not causal |
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|
what diagnostic tests do we perform for suspected feline acne?
|
initial presentation:
1. deep skin scraping and hair plucks (demodex) 2. impression smear cytology - smear sebum attached to hair shaft from hair pluck onto a slide. Express exudate from fistulous tracts- evaluate for cytological presence of cocci and rod shaped bacteria and Malassezia chronic , recurrent, or severe 1. histopath: punch biopsies from discrete comedones - ask the pathologist to search for evidence of primary keratinisation defect, folliculitis and furunculosis, demodex, dermatophytes and bacteria with special stains 2. bacterial and fungal culture: skin biopsy for bacterial and fungal culture |
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|
what is a callus?
|
A thickened plaque that develops over a bony prominence or pressure point in response to repeated pressure or frictional trauma and acts as a protective response
|
|
|
how does callus pyoderma arise?
|
callus pyoderma develops as a sequelae to repeated trauma to the callus. canine calluses contain dilated keratin filled hair follicles. Rupture of these follicles and traumatic implantation of hairs induces secondary bacterial furunculosis and a foreign body response
|
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|
a 18 month boxer presents with lameness, pain and on PE you notice multiple nodules and haemorrhagic bullae in between the forelimb digits. What do you suspect and what do you want to rule out first?
|
interdigital furunculosis
- rule out demodex (deep skin scraping) and dermatophytes (fungal culture) causing secondary interdigital furunculosis if lesions are also present elsewhere (other than digits) then all other causes of deep bacterial folliculitis and furunculosis must be investigated |
|
|
what diagnostic tests do we perform on a dog with suspected interdigital furunculosis?
|
1. direct smear by squeezing contents of nodule, pustule or bullae- cytological evaluation and stain with Diff Quik
- if there are no intact lesions then sample exudate from fistula and make impression smear of fluid contents - if there are abundant bacilli then tissue should be submitted for C & S 2. deep skin scraping to rule out demodex (important for all deep pyodermas) 3. skin biopsy -histological exam and bacterial and fungal culture further diagnostic testing: - CBC, biochem, UA, ACTH stimulation test - free T4 testing, TSH - for interdigital furunculosis- evaluation of underlying allergic skin disease (elimination diets, intradermal allergy testing) |
|
|
we commonly take biopsies for canine acne and callus pyoderma. True or false?
|
false, rarely biopsied. But is routine to biopsy for all other causes of localised and generalised deep bacterial pyoderma
|
|
|
what are the major diagnostic tests to perform on an animal with nodules, draining tracts or non-healing wounds?
|
cyology, culture and sensitivity
|
|
|
list some of the differential diagnoses of nodules and discharging sinuses in dogs and cats
|
bacterial
- Actinomyces - Actinobacillus - Nocardia - Mycobacterium - canine leproid granuloma - feline leproid granuloma fungal - Crytococcus - Sporotrichosis - Phythiosis - Aspergillosis parasites/protozoa - Leishmania non-infectious - foreign body - juvenile cellulitis (dogs only) - neoplasia - sterile nodular panniculitis - histiocytosis |
|
|
what dog breeds are commonly affected by leproid granuloma?
|
boxers and boxer Xs
other short coated breeds i.e. staffs, dobermans |
|
|
describe distribution of canine leproid granuloma
|
restricted primarily to ears
+/- head or thoracic limbs firm or ulcerated nodular lesions in dermal and SQ tissue |
|
|
what are the clinical signs for a cat with leproid granuloma?
|
- focal, occasionally ulcerated nodules, typically on head and distal limbs (although can occur anywhere including tongue, lips and nasal planum)
- clinical course is aggressive and locally recurrent however cats may develop widespread lesions over several weeks |
|
|
what causes Mycobacterial panniculitis in cats?
|
a common syndrome in cats characterised by chronic infection of the skin and subutis with rapidly growing Mycobacteria (RGM). Preference of RGM for fat means we tend to see in obese animals and in lipid rich tissues such as panniculus and inguinal fat pads
|
|
|
describe the lesions present on cats with mycobacterial panniculitis
|
- localised infection of skin and subcutis
- early lesions typically in inguinal area - characterised by draining tracts with purple-blue skin indentations ("pepper-pot" appearance) and patchy alopecia - palpation of affect skin and SQ reveals variable fluctuant and firm ropey areas - typically a watery exudate from fistulae but can be purulent with secondary bacterial infection - not overtly painful and usu not systemically unwell |
|
|
describe diagnosis of RGM infections
|
- cytology and histopathology of lesions reveal pyogranulomatous inflammation with low numbers of acid fast bacilli
- the diagnosis can be readily obtained by culture of fluid aspirated through intact disinfected skin (want to avoid surface contaminants) - culture of deep tissue samples can also be attempted - PCR to identify organisms |
|
|
regarding otitis, when are radiographs indicated?
|
only when suspect tympanic bulla pathology
|
|
|
3 most common primary causes of otitis externa
|
1. atopy
2. food allergy 3. ear mites (otodectes) |
|
|
up to ___% of food allergic dogs develop otitis externa
|
80%
|
|
|
otitis in young dogs <12 months old should raise the index of suspicion for _________
|
AFR (food allergy)
|
|
|
cats with otodectic mites are often asymptomatic. True or false?
|
true and hence pose a source of infection for adult dogs
|
|
|
hypothyroidism and hyperadrenocorticism are commonly associated with otitis externa. True or false?
|
false.
sertoli cell tumours may be |
|
|
list perpetuating factors in otitis externa
|
- progressive stenosis
- ear canal fibrosis - ear canal calcification - chlolesteatoma - otitis media |
|
|
for Malassezia up to __/HPF is considered normal flora in the external ear
|
5
|
|
|
mechanisms to visualise integrity of the tympanic membrane
|
1. visualisation of fluid escaping tympanic cavity via eustachian tube
- colour irrigation with aqueous povidone iodine solution 2. radiology - best views are VD, rostrocaudal open mouth and lateral oblique - usu underestimates pathologic changes in middle ear due to superimposition of surrounding tissues and minimal radiographic changes associated with otitis media - radiographic changes associated with otitis media include: increased soft tissue opacity, sclerosis and thickening or lysis of tympanic bulla wall, sclerosis of petrous temporal bone and calcification of external ear canals 3. positive contrast canalography - 2-5ml positive contrast and rad 4. CT - ability to take cross sectional images overcomes problem of superimposition -distinguishes air and bone well 5. MRI - superior to CT for evaluating soft tissue densities of middle ear - less useful than CT for evaluating bony changes in tympanic cavity |
|
|
what is myringotomy?
|
myringotomy is a deliberate incision into an intact tympanic membrane to obtain samples from middle ear and to provide a route of drainage for accumulated middle ear effusion
|
|
|
what are the most common skin problems presented to vets?
|
1. pruritis
2. alopecia 3. lumps and swelling 4. otitis (dogs esp) |
|
|
atopy is most common in dogs < 6 months old. True or false?
|
false, rarely diagnosed in dogs under 6months
|
|
|
acute onset of severe pruritis is frequently associated with
___________ and ___________ |
scabies and AFR
|
|
|
which pruritic skin conditions demonstrate seasonality?
|
- FAD or insect bite hypersensitivity
- atopy |
|
|
a repeated response to low dose glucocorticoid therapy or antihistamines as the sole therapeutic agent is strongly suggestive of ___________
|
allergies
|
|
|
a 12yo bichon presents with bilateral diffuse truncal non-pruritic alopecia and you suspect hyperadrenocorticism. What other clinical signs do you look for?
|
- PU/PD
- weakness - exercise intolerance - polyphagia - pendulous abdomen |
|
|
what diseases are erythema macules most commonly seen with?
|
- Staphyloccocal pyoderma
- FAD - fly bites - contact dermatitis - erythema multiforme |
|
|
what conditions do we most commonly see papules with?
|
- bacterial pyoderma
- FAD - scabies - Atopy - fly bite HS - contact dermatitis |
|
|
what is an epidermal collarette?
|
a circular ring of scale formed when a focal point of infection spreads outwards as an enlarging circle causing the stratum corneum to lift upwards. The end result is a circular patch of alopecia surrounded by a rim of scale, usually associated with bacterial pyoderma
secondary lesion (?) |
|
|
what is a comedone?
|
a dilated hair follicle filled with cornified cells and sebaceous material
occurs with diseases that affect hair follicles such as demodicosis, endocrine diseases and cornification defects |
|
|
how do vesicles form?
|
lack of cohesion between epidermis and dermis (i.e. pemphigus)
|
|
|
indications for trichograms
|
- may be useful in any alopecic animal
- suspected dermatophytosis 1) shedding conditions, endocrinopathies 2) if self inflicted 3) Demodex 4) help to diagnose colour dilutant alopecia (melanin in hair present in big clumps) |
|
|
why is it useful to ask clients which came first i.e. itching or lesion?
|
because certain conditions have certain patterns i.e. atopy often called "an itch that rashes" whereas scabies has primary papule lesions which then itch
|
|
|
list diseases that may trigger a superficial bacterial folliculitis
|
- atopy
- FAD - food allergy dermatitis - hypoT - hyperA - primary keratinisation disorders - colour dilutant alopecia |
|
|
what should we being looking for when doing cytology on suspected superficial bacterial folliculitis?
|
determine the predominant inflammatory cell type and the number and type of bacteria +/- yeast with oil immersion lens (1000x)
- evaluate for presence of healthy neutrophils, degenerate neutrophils, eosinophils, extracellular and intracellular cocci and acantholytic cells |
|
|
always do take a biopsy for histology when suspect bacterial skin disease. True or false?
|
false. histological evaluation is of no value in the diagnosis of bacterial skin diseases although is indicated if sterile pustular skin disease i.e. pemphigus or deep bacterial pyoderma
|
|
|
diseases that cause inflammation and increased sebum production provide a cutaneous micro-environment which encourages overgrowth of what organism?
|
Malassezia pachydermatis (yeast)
|
|
|
what are the possible causes of self induced, non-inflammatory alopecia in a cat?
|
1. Cheyletiella, Demodex, Notoedres
2. FAD, AFR, atopy 3. dermatophytes 4. psychogenic alopecia |
|
|
what is believed to be the most common underlying cause of feline eosinophilic dermatoses?
|
feline allergic dermatitis
|
|
|
sarcoptes is very rare in cats. True or false?
|
true
|
|
|
in Australia what is the major cause of miliary dermatitis and non-inflammatory alopecia in cats?
|
FAD
no breed, age or sex predilection for FAD in cats but often cats 6 months + |
|
|
what is the most common clinical sign of a cat with AFR?
|
a non-seasonal pruritus which is most commonly localised to the face. a concurrent bilateral ceruminous otitis externa is often present. GIT signs reported in some card
|
|
|
how long should an elimination diet be fed to a suspected AFR cat?
|
minimum 8 weeks
|
