Infections with Penicillium spp are rare in domestic animals. However, the fungus has been isolated from a case of feline dermatosis; from orbital cellulitis and sinusitis with pneumonia in another cat; from invasive destructive disease of nasal tissues in dogs; from invasive lesions in the lungs, air sacs, liver, and other tissues in captive toucanets (P griseofulvum); and from systemic disease in bamboo rats (P marneffei) in southeast Asia. Penicillium spp are widely distributed in nature and are found in soils, grains, and various foods and feeds.

Clinical Findings and Lesions

Dogs with nasal penicilliosis have chronic sneezing and an acute to chronic nasal discharge that varies from intermittent hemorrhagic to intermittent or continuous mucoid or mucopurulent. Radiographic findings include areas of turbinate destruction with increased radiolucency. Grossly, the nasal mucosa has foci of necrosis and ulceration; microscopically, fungal hyphae may form a thick mat over an intact mucosa adjacent to these foci.

Diagnosis

Diagnosis is based on fungal culture, character of the lesions and presence of fungal hyphae, and a positive agar-gel double-diffusion test. Cultural isolation of a Penicillium sp must be accompanied by demonstration of tissue invasion by the fungus for confirmation. In tissues, P marneffei closely resemble the yeast phase of Histoplasma capsulatum.

Treatment

Surgical turbinectomy with curettage has been combined with flushing of the nasal cavity with 1% tincture of iodine or povidone-iodine (10:1) and oral thiabendazole. Fluconazole, 2.5–5.0 mg/kg/day for 2 mo, has been used to successfully treat some dogs with nasal penicilliosis.

Last full review/revision March 2012 by Joseph Taboada, DVM, DACVIM