Curvularia spp

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Curvularia spp viewed under light microscopy

Curvularia spp are an opportunistic fungus that is normally found in damp environments and rarely cause disease in dogs.

They are normally considered a non-dermatophytic fungi that requires underlying dermatopathy to invade the skin, but can cause disseminated cutaneous phaeohyphomycosis[1].

The incidence of these infections is greater in warm and humid climate[2], and immunocompromised dogs are predisposed.

Species which are pathogenic include:

  • Curvularia lunata[3]
  • Curvularia geniculata[4]

Clinically affected dogs usually present with paronychia and ulcerated skin lesions, often with secondary bacterial infections. Focal areas of alopecia with papules and nodules with ulceration overlain by crusts are common, with lesions most prevalent on the dorsum and the lateral aspects of the trunk and extremities[5]. Draining sinuses may occur within the skin, but visceral dissemination is rare[6].

Ocular disease has been reported with this fungus, with mycotic keratitis common in some cases of indolent corneal ulcers[7][8].

Thick walled fungal hyphae are usually detected in impression smears from skin lesions. Staining with periodic acid-Schiff's stain is usually confirmatory.

Treatment with generalized phaeohyphomycosis usually requires parenteral amphotericin B or itraconazole.

References

  1. Swift IM et al(2006) Successful treatment of disseminated cutaneous phaeohyphomycosis in a dog. Aust Vet J 84(12):431-435
  2. Philpot CM & Berry AP (1984) The normal fungal flora of dogs. A preliminary report. Mycopathologia 87(3):155-157
  3. Jand SK & Gupta MP (1989) Dermatomycosis in dogs. Mycoses 32(2):104-105
  4. Bridges CH (1957) Maduromycotic mycetomas in animals; Curvularia geniculata as an etiologic agent. Am J Pathol 33(3):411-427
  5. Herráez P et al (2001) Invasive phaeohyphomycosis caused by Curvularia species in a dog. Vet Pathol 38(4):456-459
  6. Elad D et al (1991) Eumycetoma caused by Curvularia lunata in a dog. Mycopathologia 116(2):113-118
  7. Ben-Shlomo G et al (2010) Curvularia keratomycosis in a dog. Vet Ophthalmol 13(2):126-130
  8. Qualls CW Jr et al (1985) Mycotic keratitis in a dog: concurrent Aspergillus sp and Curvularia sp infections. J Am Vet Med Assoc 186(9):975-976