Candidiasis

Introduction

Candida spp

Candidiasis is a fungal infection caused by Candida spp., most commonly Candida ablicans that affects many species.

The yeast is normally present on skin and in the GI tract. Symptoms of disease are usually only seen in immunocompromised animals following opportunistic infection. It is most common in the bird (see Candidiasis - Birds) but has also been reported in rabbits, horses, pigs, cows, sheep, cats and dogs - in particular neonates.

Clinical Signs

Lesions are found on mucous membranes and at mucocutaneous junctions most commonly. The disease will usually remain localised to the mucocutaneous junctions, but on rare occasions it may spread systemically.

Gross clinical signs include:

  • Exudative, papular, pustular to ulcerative dermatitis
  • Raised, circular white plaques or ulcers with overlying scabs
  • Keratinous thickening of tissue
  • Stomatitis and otitis externa

Microscopically there is evidence of:

  • Spongiotic neutrophilic pustular inflammation
  • Parakeratosis
  • Ulcerations
  • Superficial exudate containing organisms

Infection may cause also cause a variety of other clinical signs depending on the species and the site of infection, for example mastitis, arthritis, diarrhoea and general malaise.

Predisposing factors

  • Immunosuppressive drugs
  • Immunosuppressive disease
  • Indwelling urinary or intravenous catheters
  • Antibiotic administration

Diagnosis

Diagnosis can be confirmed via microscopic examination and identification of the fungus following a skin scrape of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a gram-positive ovoid, budding yeast with or without hyphae. Culture of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.

Treatment

Topical or systemic anti-fungals are used to treat the infection.

Prognosis

Prognosis depends on both the severity of infection and the animal affected.

Also see:

Candidiasis in Birds
Candidiasis in Rabbits

References

Merck & Co (2009) The Merck Veterinary Manual (Ninth Edition), Merial