Canine Bacterial Pyoderma Flashcards
What are the bacterial pyoderma syndromes (superficial)
1) Bacterial overgrowth
2) Superficial bacterial pyoderma
3) Acute moist dermatitis / pyotraumatic dermatitis (hotspots)
4) Canine recurrent bacterial pyoderma
What are the different types of bacterial pyoderma syndromes (deep)
1) Mucocutaneous bacterial pyoderma
2) Deep bacterial pyoderma
3) Bacterial furunculosis
What is #1 cause of bacterial pyoderma in dogs
Staph pseudintermedius
What is underlying cause of majority of bacterial pyoderma
allergies
-inflammation of skin causes skin barrier to be compromised
Types of commensal opportunitists
> 90% Staph
-Staph pseudintermedius is most common
-S. aureus (cats)
-S. schleifri
-S. epidermidis
-Coag negative?
What is another name for skin fold pyoderma
Intertrigo
What is another name for interdigital pyoderma
Pododermatitis
Canine bacterial pyoderma is secondary to another issue. how do you determine this
Cytology (impression, acetate tape)
What might cause bacterial overgrowth
the environment
-skin fold
-interditial
not many inflammatory cells (not breaking skin barrier) but will have high count
typically secondary to allergy or conformation
How do you treat bacterial overgrowth
No need for systemics
use topical therapies preferred - use chlorhexidine 2-4%
typically secondary to allergy conformation
What is a typical sign of bacterial overgrowth
Malodor
What breed is predisposed to lip ofld pyoderma
german shepherd
st bernards
What topical would you use for multifocal
shampoos or spreads
acute manifestation of pruritic trauma
excoriation often secondarily infected
Acute moist dermatitis “hot spots”
also called pyotraumatic dermatitis
Acute moist dermatitis is often secondary to
allergy
acute moist dermatitis often occur where
facial lesions common
flanks
How do you treat acute moist dermatitis
clip and clean
diagnose with cytology (impression smear)
Superficial bacterial pyoderma is often
follicular (papules, pustules, epidermal collarettes)
if non-follicular (impetigo, pemphigus)
not due to trauma
often secondary to allergy
Pustules that arent follicular
1) Pemphigus
2) Impetigo (puppies born in dirty environments)
How do you treat superficial bacterial pyoderma
three weeks antimicrobial therapy (one week past resolution)
For superficial bacterial pyoderma, how often should you bathe with antimicrobial shampoo
three times a week
(just as effective as 3 weeks of antimicrobials)
What is most common cause of epidermal collarette
1) Bacterial pyoderma
2) Dermatophytosis
3) Demodecosis
What are causes of recurrent bacterial pyogerma
1) Inadequate duration/dose re:therapy
2) Anatomic predisposition
3) Allergy
What are causes of bacterial pyoderma
1) Allergy
2) Endocrinopathies
3) Immunocompromise
4) Congenital immuno-insufficiency (GSD)
How do you treat recurrent bacterial pyoderma
1) Systemic antibiotics?
2) Topical therpay preferred 3x week
3) Twice weekly- maintenance therapy
4) Treat the primary cause (ie allergy, immunocompromise)
T/F: Staphylococcal bacterin vaccine works well
False
What might cause chronic bacterial pyogderma
1) Mucocutaneous bacterial pyoderma
2) Deep bacterial pyoderma
3) Bacterial furunculosis
4) Methicillin-resistant Staph
-Culture interpretation and treatment options
Where does mucocutaneous pyoderma occur
Lip margins (cheilitis)
Nasal planum (nares)
Vulva
Canthi/eyelids
can mimic immune mediated disease (ie DLE)
What does mucocutaneous pyoderma look like
-Erythema
-Crusting
-Depigmentation
-Fissuring (nasal planum): vasculitis (GSD)
(looks like immune mediated ie DLE)
What are differentials for mucocutaneous pyoderma
Allergy
Neoplasia (SCC)
Immune mediated disease (DLE, MCLE)
T/F: histologic changes of mucocutaneous bacterial pyoderma are very simular to those of the lupus group of diseases like discoid lupus erythematosus
TRUE - biopsy is often ambiguous
How do you treat mucocutaneous pyoderma
Cytology to confirm (intracellular) bacteria
4-8 weeks of systemic antibiotics
Culture highly recommended
Mupirocin (gram +) topically BID
Mandatory to do these things before biopsy
What should you do for mucocutaneous pyoderma before biopsy
1) Cytology to confirm (intracellular) bacteria
2) 4-8 weeks of systemic antibiotics
3) Culture highly recommended
4) Mupirocin (gram +) topically BID
T/F: yeast can be ingested by neutrophils
False - yeast cant be ingested by neutrophils
How do you confirm mucocutaneous pyoderma
intracellular bacteria
What are signs of deep bacterial pyoderma
Ulcers
Hemorrhage
Plaques/nodules
How do you treat deep bacterial pyoderma
4-6 weeks antibiotic therapy
two weeks past resolution
systemic preferred
culture is highly recommended
How do you culture deep bacterial pyoderma
1) biopsy is preferred - 4mm biopsy punch
trim off epidermis (on the top)
2) Squeeze from underneath - bacterial is pushed outwards and you can culture
exploded hair follicles
often mistaken for foreign body
can lead to deep secondary pyoderma
bacterial furunculosis
bacterial furunculosis typically occurs where
interdigital/ intertriginous spaces
short-coated dogs
What typically causes bacterial furunculosis
typically allergy
conformational possible
What is typically bacterial furunculosis typically mistaken as
foreign body
What does bacterial furunculosis typically look like
draining tracts
pyogranulomatous inflammation
fibrosis
How do you treat bacterial furunculosis
4-6 weeks systemic antibiotics
two weeks past resolution
topical antimicrobial prevention
control underlying cause (allergy/orthopedic)
cyclosporin- for chronic anti-inflammatories
Reasons why bacterial pyoderma will not resolve
1) Error in antibiotic selection
2) Dosage error
3) Inadequate duration of therapy
4) Lack of compliance
5) Resistance infection (above conditions are ruled out)
T/F: you cant tell difference between Methicillin susceptible staph vs resistant staph
True
What are risk factors for MRSP
-Previous history of antibiotic exposure
-Fluoroquinolones
-Previous clinic/hospital visits (community vs hospital acquired)
-Primary disease (risk factor for pyoderm)
-Immunocompromise
T/F: Methicillin-Resistant Staph has an identical appearance to susceptible pyoderma
True
T/F: Methicillin-Resistant Staph is more severe than susceptible
False - (aureus excluded?)
T/F: you can differentiate Methicillin-Resistant Staph on cytology
false you need to do a cuture
Methicillin-Resistant Staph is resistant to
all beta-lactam antibiotics (penicillins/cephalosporins)
What is needed for diagnosis of Methicillin-Resistant Staph
culture required
How is Methicillin-Resistant Staph transmitted
surfaces - not airborne
What lesions are most at risk for transmission of Methicillin-Resistant Staph
exudative lesions
Methicillin-Resistant Staph can be killed with
conventional bactericidal cleaners
How do you get culture sample for superficial vs deep bacterial pyoderma
Superficial: under crusts, pustules
Deep: Draining tracts, ulcers, biopsy, squeezes
You need to always pair culture with
cytology
What are the indications for culture
1) Deep infection (tough to treat topically, prolonged course)
2) Mixed infection
3) Does not respond to anticipated treatment
4) Unable to treat topically (disseminated)
What should you use to treat bacterial pyoderma if not methicillin-resistant staph
Clindamycin or Cephalexin
What should you use to treat bacterial pyoderma if you are suspicious of methicillin-resistant staph
Clindamycin
On your lab results, what indicates Methicillin-Resistant Staph
Oxacillin - R
How do you treat Methicillin-Resistant Staph
slower to respond to therapy
use culture reuslts
one week past resolution (superficial)
two weeks past resolution (deep)
How should you pick you antibiotic selection based on culture
1) Susceptible
2) Narrow-spectrum antbitoics preferred
3) Adverse effects
4) Ease of administration
What topical treatment should you use for methicillin-resistant staph
2-4% chlorhexidine shampoo/sprays/wipes/mousse
three times weekly (more is better)
contact time 5-10 minutes
dilute bleach
aceelerated hydrogen peroxide
topical antibiotics
-Mupirocin
-Silver sulfadiazine
-Aminoglycoside
What should you do for vigilance of methicillin-resistant staph
Isolation
Environmental cleanup
Difficult to transmit to healthy individuals
carriage sites: anus, nose, mouth
