47. Pyoderma. Demodicosis. Fungal dermatopathies Flashcards
Pyoderma?
Pyoderma
A skin disease that is pyogenic
Causes:
§ Coagulase positive Staphylococcus spp.
§ Coagulase negative Staphylococcus spp.
§ Coagulase negative Micrococcus spp.
§ ɑ-haemolysing Streptococcus spp.
§ Pseudomonas aeruginosa
§ Proteus vulgaris } Gram negative rods
§ E. coli
Types of pyoderma
§ Surface pyoderma – Hot spot form; Intertrigo form
§ Superficial pyoderma – Impetigo form; Folliculitis form
§ Deep pyoderma – Furunculosis form; Cellulitis form
Surface pyoderma?
SURFACE PYODERMA
Involvement of the superficial horny later
Hot spot form
Acute, moist dermatitis; Pyotraumatic dermatitis; Rapid
development
Predisposed: Long-haired breeds in hot, humid weather
May be enhanced by self-trauma
Cause: Fleas; Otitis; Paraproctitis; Neurosis; Allergy
Treatment
§ Eliminate underlying cause
§ Clipping; Shampoo
§ Short-term glucocorticoids & antibiotics
Intertrigo form
Anatomical defects; Warm; Humid; Dark/; Anaerobic; Selftrauma
Location
§ Lip fold: Cocker spaniel
§ Facial fold: Brachycephalic dogs (see Fig. 48.1)
§ Vulvar fold: Obese; Prematurely-spayed dogs
(see Fig. 48.1)
§ Tail fold: Corkscrew-tailed breeds
§ Body fold pyoderma
§ Generalised pyoderma: Shar Pei
Treatment
§ Plastic surgery
§ Daily: Cleaning with disinfectants; Drying; Drying;
Powder; Solutions; Shampoos
Superficial Pyoderma?
SUPERFICIAL PYODERMA
Most common skin disease in dogs
Impetigo form
Juvenile pustular dermatitis; Puppy pyoderma; Non-follicular
pustule
Predisposed: Young puppies prior to puberty
Underlying causes
§ Endoparasite
§ Ectoparasite
§ Poor nutrition
§ Unhygienic environment
Clinical signs
§ Sub-corneal: Papule; Pustule; Yellow crusts;
§ May be asymptomatic
Treatment
§ Treat the underlying cause
§ Antibacterial shampoos
Folliculitis form
Superficial folliculitis
Bacterial infection at the level of intact hair follicle/epidermis
Predisposed: Any age; Young dogs
Folliculitis is always a secondary problem to any of the
following:
§ Flea allergy § Atopy
§ Endocrine disorder § Parasites
§ Immunosuppression
Clinical signs
§ Pustules with protruding hair § Papules
§ Epidermal collarettes § Crusts
§ “Moth-eaten” alopecia § Pruritis
Treatment
§ Treat the underlying cause
§ Antibiotics (for minimum 3 weeks parenterally + topically)
Deep Pyoderma?
DEEP PYODERMA
Bacterial infection of the skin beneath the hair follicle, involving both
the dermal & subcuticular tissues
Predisposed: Great Dane; Boxer; Doberman; Vizsla
Cause: Staphylococcus pseudointermiedius et al.
Underlying cause is always present:
§ Demodicosis
§ Foreign body
§ Dermatophytes
§ Endocrine disorder
§ Immunodeficiency
Nasal pyoderma
Predisposed: Dolichocephalic breeds (long-nosed)
Treatment: Elizabethan collar; Antibiotics
Interdigital pyoderma (pododermatitis)
Predisposed: Short-coated breeds
Causes: Foreign body; Demodex spp.; Atopy; Trauma
Clinical signs:
§ Swollen feet § Pain
§ Alopecia due to licking § Pus
§ Paronychia § Nodules*
§ Ulceration* § Fistulas*
§ Furunculosis*
*Chronic cases
Treatment
§ Treat the underlying cause
§ Surgical drainage
§ Footbath with saline
§ Antibiotics
Other deep pyodermas
§ Pressure point pyoderma (callus pyoderma)
§ GS pyoderma
§ Pyotraumatic folliculitis
§ Generalised deep folliculitis, furunculosis & cellulitis
Antibiotics for pyoderma?
ANTIBIOTICS FOR PYODERMA
First pyoderma
§ Cefalexin § Cefadroxil
§ Clindamycin § Lincomycin
§ Sulfadimethoxine
Based on resistance
§ Amoxiclav § Cefovecin
§ Marbofloxacin § Norfloxacin
§ Pradofloxacin § Ciprofloxacin
Demodex canis?
Demodicosis
Infection by mites
DEMODEX CANIS
Normal inhabitant of the skin & hair follicles
Mites are transferred from the bitch on the first 3 days of the neonate’s life
Some dogs become sensitive to the mites due to cellular
immunodeficiency
Predisposed: Old English sheep dog; Shar Pei; German shepherd;
Collie; White West Highland Terrier; Doberman
Three forms are described based on location:
Localised: Head & FL
§ Patchy alopecia
§ Erythema
§ Scaling → Hyperpigmentation
Generalised: Head, legs & trunk; Juvenile/adult onset
§ Many lesions
§ Secondary pyoderma
Pododemodicosis: Feet
§ Thickened skin
§ Hyperpigmentation
§ Secondary pyoderma
§ Oedema
+ Otitis externa
Demodex cati?
DEMODEX CATI
Rare
Diagnosis: CSx & Skin scrapings; Biopsy
Treatment
§ Selamectin (spot on)
§ Clip hair; Bathe
Treatment of demodicosis?
TREATMENT OF DEMODICOSIS
Juvenile localised demodicosis
Up to 90% of cases heal spontaneously
If there are only a small number of mites, acaricide therapy isn’t necessary
Larger infestations would warrant shampooing, spot-on
moxidectin and/or an amitraz-laced collar.
Generalised demodicosis
Causes deep pyoderma
Treatment requires intense therapy & immune-stimulation
§ Flushing with amitraz
§ Hair clipping
§ Shampoo with benzoyl-peroxide
PO treatment
§ Ivermectin § Afoxolaner
§ Doramectin § Sarolaner
§ Moxidectin § Milbemycin
§ Fluralaner
Subcutaneous: Ivermectin
Fungal dermatopathies?
Fungal Dermatopathies
Types:
§ Superficial mycoses
§ Subcutaneous mycoses
§ Systemic mycoses
Superficial Mycoses Dermatophytosis(ringworm)?
SUPERFICIAL MYCOSES
Dermatophytosis (ringworm)
Cause: Microspoum canis, gypseum et persicolor; Trichophyton
mentagrophytes, verrucosum et Terrestre
Clinical signs
Dog
§ Patchy alopecia § Scales
§ Folliculitis § Crusts
§ Plaques §
Cat
§ “Cigarette ash”-like § Miliary dermatitis
§ Patchy alopecia § Crusts
Diagnosis
§ Fungal culturing
§ Dermatophyte test medium (DMT)
§ Woods-lamp (uses ultraviolet light)
§ KOH preparations by microscopy
§ Biopsy
Treatment
In healthy animals, the condition is self-limiting
§ Systemic: Griseofulvin; Ketoconazole
§ Topical: Hair-clipping; Enilconazole; Ketoconazole
§ Vaccine: Biocan M
Candidiasis(superficial mycoses)?
Candidiasis
Cause: Candida albicans (+ other underlying factors)
Clinical signs
§ Acute moist dermatitis § Otitis externa
§ Mucosa ulceration § Skin ulceration
§ Grey-white plaques § Paronychia
§ Vaginal discharge
Diagnosis: Direct smear; Culture; Biopsy
Treatment
None are licenced in dogs
§ Topical: Miconazole; Enilconazole
§ Systemic: Ketoconazole; Amphotericin B
Malassezia Pachydermatitis(yeast)?
Malassezia pachydermatitis (yeast)
Cause: Pityrosporum canis (normal commensal of the ear)
Problems occur when the yeast overgrows
Usually secondary to:
§ Allergodermatitis
§ Endocrinopathies
§ Pyoderma
§ Demodicosis
Clinical signs
§ Alopecia § Scaling
§ Pruritic seborrhoea § Lichenification
Diagnosis: Cytology; IF microscopy; Culture
Treatment: Eliminate underlying causes/disease
§ Topical: Antifungals (ketoconazole)
§ Systemic: Ketoconazole
Subcutaneous Mycosis?
SUBCUTANEOUS MYCOSIS
§ Eumycotic mycetoma
§ Phytiosis
§ Sporotrichosis
Systemic Mycosis?
SYSTEMIC MYCOSIS
Cryptococcosis
Cause: Cryptococcus neoformans
Clinical signs: Nodules; Papules (these may ulcerate)
Diagnosis: Biopsy; Culture (Sabouraud’s agar)
Treatment: Surgical excision; Ketoconazole
Prognosis: Guarded
General treatment of fungal dermatopathies(topically and systemically)?
GENERAL TREATMENT OF FUNGAL DERMATOPATHIES
Topically
§ Imaverol solution
§ Malaseb shampoo
Systemically
§ Itraconazole: Candida spp.; Malassezia spp.; Aspergillus
spp.; Leishmania spp.
§ Itrafungol; Orungal
§ Fluconazole: Fungal meningitis; Oral candida spp.
§ Terbinafin: Trichophyton spp. nail bed inflammation
