Pseudallescheria spp

From Dog
Pseudallescheria spp under light microscopy[1]

Pseudallescheria spp are an opportunistic fungal infection of dogs[2].

They are normally considered a non-dermatophytic fungi in dogs that requires underlying dermatopathy to invade the skin[3]. The incidence of these infections is greater in warm and humid climate[4].

Both dermal, ocular and systemic phaeohyphomycosis due to granuloma formation have been reported, and iatrogenic infections associated with wound dehiscence is common[5].

Species which are pathogenic include:

  • Pseudallescheria boydii

Clinical signs of Pseudallescheria spp infections are often vague, but can include sneezing and epistaxis[6] due to mycotic rhinitis and sinusitis are common.

Lameness[7], pyogranulomatous periorchitis[8], pneumonia and keratoconjunctivitis sicca have been reported[9].

Generalized pulmonary phaeohyphomycosis have been reported using radiographic and ultrasonographic studies[10].

Thick walled fungal hyphae are usually detected in impression smears from skin lesions. Staining with periodic acid-Schiff's stain is usually confirmatory[11].

Treatment with generalized phaeohyphomycosis usually requires aggressive treatment with amphotericin B, itraconazole and ketoconazole, with curettage of the local area.

The prognosis for paecilomycosis is poor, although some treatment success has been reported.


  1. Science Direct
  2. Jang SS & Popp JA (1970) Eumycotic mycetoma in a dog caused by Allescheria boydii. J Am Vet Med Assoc 157(8):1071-1076
  3. Jand SK & Gupta MP (1989) Dermatomycosis in dogs. Mycoses 32(2):104-105
  4. Philpot CM & Berry AP (1984) The normal fungal flora of dogs. A preliminary report. Mycopathologia 87(3):155-157
  5. Walker RL et al (1988) Eumycotic mycetoma caused by Pseudallescheria boydii in the abdominal cavity of a dog. J Am Vet Med Assoc 192(1):67-70
  6. Bruskiewicz K & Crawford-Jakubiak M (2011) Pseudallescheria boydii species complex fungal rhinitis and sinusitis in a dog. J Am Anim Hosp Assoc 47(5):365-369
  7. Elad D et al (2010) Disseminated pseudallescheriosis in a dog. Med Mycol 48(4):635-638
  8. Allison N et al (1989) Eumycotic mycetoma caused by Pseudallescheria boydii in a dog. J Am Vet Med Assoc 194(6):797-799
  9. Smedes SL et al (1992) Pseudallescheria boydii keratomycosis in a dog. J Am Vet Med Assoc 200(2):199-202
  10. Sutton DA et al (2008) Pulmonary Phialemonium curvatum phaeohyphomycosis in a Standard Poodle dog. Med Mycol 46(4):355-359
  11. Baszler T (1988) Disseminated pseudallescheriasis in a dog. Vet Pathol 25(1):95-97