Yeast-like fungi

FUNGI

Candidosis

Caused by Candida spp.
Noramlly present on skin and in GI tract
Immunocompromised animals may show symptoms
Usually lesions on mucous membranes and at mucocutaneous junctions
Grossly:
- Exudative, papular, pustular to ulcerative dermatitis
- Stomatitis and otitis externa may develop
Microscopically:
- Spongiotic neutrophilic pustular inflammation
- Parakeratosis
- Ulcerations
- Superficial exudate containing organisms

Caused by Malassezia pachydermatis
Yeast, normally present in external ear canal and skin
Clinical disease may cause yeast to proliferate and cause infection
Grossly:
- Regional lesions: muzzle, ears, interdigital, perianal
- Or generalised disease
- Erythematous, hyperpigmented, lichenified and scaly lesions with alopecia
Microscopically:
- hyperkeratosis, parakeratosis
- Spongiotic pustular dermatitis
- Acanthosis
- Organisms are usually present, minimum 3-5 yeasts per high-power field must be found to imply cause of disease

Implicated in cases of:
- Pyelonephritis, pneumonia, septicaemia and meningitis (humans)
- Mastitis and abortion in cattle
- Systemic infection of monkeys and dogs

Trichosporonosis beigelii
- Implicated in feline nasal granuloma, skin infections in horses and monkeys, mastitis in cattle and sheep and in feline bladder infections

Cryptococcus neoformans causes granulomatous rhinitis in cats, see respiratory infections
Candida is an opportunistic pathogen at mucus membranes, causing thrush.
Blastomyces dermatitidis in blastomycosis in lungs
Histoplasma capsulatum in histoplasmosis in lungs
Candida spp. in candidiasis
Malassezia pachydermis in malassezia dermatitis