Penicillium spp

From Dog
Penicillium spp spores viewed under light microscopy[1]

Penicillium spp are a keratinophilic hyphomycetes fungi which are a normal commensal of canine skin worldwide[2].

Coinfection with other dermatophytes such as Microsporum spp is very common[3].

Penicillium spp rarely cause disease but following skin damage, may proliferate within the dermis and cause ulcerative lesions.

Species which are pathogenic to dogs include:

Clinical signs of infection include dermatitis, rhinitis and otitis externa predominating[5]. However, disseminated opportunistic infections have been reported in dogs, with peripheral lymphadenopathy[6] and bronchopneumonia[7].

The most common disease associated with Penicillium infection is 'garbage eating', resulting in secondary tremorgenic mycotoxicosis, characterized by acute gastroenteritis, tremors and seizures.

Diagnosis is based on culture of the fungus in a laboratory and visualization of hyphae in tissue samples. Fungal elements stained positively with Gomori methenamine silver and Periodic acid-Schiff stains. Definitive classification requires use of PCR assays[8].

Treatment would involve topical or parenteral antifungal chemotherapy with drugs such as amphotericin B, itraconazole, ketoconazole or turbinafine. Pulse treatment is recommended.

Disseminated Penicillium spp infections have a guarded prognosis due to the slow-growing nature of the fungus and parenteral treatments usually have to be extended for 4 -6 month period to effect clinical resolution..


  1. University of California
  2. Efuntoye MO et al (2002) Fungi isolated from skins and pens of healthy animals in Nigeria. Mycopathologia 153(1):21-23
  3. Simpanya MF & Baxter M (1996) Isolation of fungi from the pelage of cats and dogs using the hairbrush technique. Mycopathologia 134(3):129-133
  4. Chaiwun B et al (2011) Investigation of dogs as a reservoir of Penicillium marneffei in northern Thailand. Int J Infect Dis 15(4):e236-e239
  5. Campbell JJ et al(2010) Evaluation of fungal flora in normal and diseased canine ears. Vet Dermatol 21(6):619-625
  6. Tomlinson JK et al (2011) Granulomatous lymphadenitis caused by Talaromyces helicus in a Labrador Retriever. Vet Clin Pathol 40(4):553-557
  7. Jones BG & Pollard RE (2012) Relationship between radiographic evidence of tracheobronchial lymph node enlargement and definitive or presumptive diagnosis. Vet Radiol Ultrasound 53(5):486-491
  8. Miyakawa K et al (2011) Pathology in practice. Penicilliosis. J Am Vet Med Assoc 238(1):51-53