Bacterial Skin Diseases Flashcards
common predisposing conditions to canine pyoderma
- allergies
- parasites
- endocrinopathies (hyperadrenocorticism/hypothyroidism)
most pyoderma lesions in animals are caused by what bacterial species?
Staphylococcus pseudointermedius
clients will be more familiar with S. aureus (because MRSA)
MRSP exists too and animals do get it
what does canine pyoderma look like under the microscope
degenerate neutrophils, cocci, and nuclear streaming
nuclear streaming is from the neutrophils losing the battle and dying and breaking apart
are bacterial skin diseases primary?
RARELY
they are SECONDARY until proven otherwise; find the underlying problem!
Canine Pyoderma Classifications (3)
- Surface
- Superficial
- Deep
based on depth of infection
2 Surface Pyodermas
- Pyotraumatic Dermatitis
- Skin Fold Pyoderma/Intertrigo
colloquial term for pyotraumatic (acute moist) dermatitis?
hot spots
how quickly do hot spots form
can be within HOURS
are hot spots a bacterial infection?
NO
clinical appearance of hot spots
moist and painful
pathogenesis of skin fold pyoderma
Moisture + skin friction –> maceration + removal of stratum corneum + poor air circulation –> bacterial overgrowth
4 common locations for skin fold pyoderma
- lip
- face
- perivulvar
- tail
why do dogs with skin fold pyoderma sometimes have yellow/green staining around the mouth?
when the toxins expressed by the bacteria mix with the saliva
treatment of surface pyodermas
topical.
no cultures really needed since no systemic therapy
3 Differntial Diagnoses for Moth-Eaten Appearance [in short-coat breeds]
- Superficial pyoderma
- Demodex
- Dermatophytosis
superficial pyoderma
bacteria infect the superficial layers of the epidermis and/or hair follicle(s)
clinical signs of superficial pyoderma
papules –> pustules –> epidermal collarettes
may or may not be pruritic
moth-eaten alopecia
diagnosis and treatment of superficial pyoderma
cytology fine, culture only needed if doesn’t respond to treatment or is a repeat offender
treat with amoxi/clav, clinda (okay empiracally); shampoos chill too
deep pyoderma
associated with the rupture of the hair follicle, affecting both the dermis and the epidermis
furunculosis
rupture of the hair follicle
clinical signs of deep pyoderma
BIG ulcers, tissue loss, draining tracts, etc. which can be local or generalized
generalized can even have lymphadenopathy or other systemic signs
5 Differential Diagnoses for Deep Pyoderma
- demodex
- fungal infection
- neoplasia
- foreign body/abscess (think nasty grass awn)
- mucocutaneous lupus erythematosus
how to diagnose deep pyoderma
C&S
cytology can and should be done but will be difficult to see since deep, low numbers, and often hidden by inflammotry cells)
treatment of deep pyoderma
systemic therapy and topical shampoos
nocardiosis
atypical deep bacterial skin infection
branching filamentous aerobic bacteria; common soil saprophytes
remove lesions surgically
canine leproid granuloma
atypical deep bacterial skin infection
slow growing mycobacterium that causes localized nodules, typically on head/pinnae; common in short-coated breeds
remove lesions surgically
