Student Case Study

Multifocal fungal osteomyelitis caused by Talaromyces spp in a dog

Lauren Bynum, Gwendolyn Levine, Lindsey Gilmour, Clark Broughton, Karen Russell, Beth

Boudreau, Stephanie Lovell, Sara Lawhon

Texas A&M University College of Veterinary Medicine

Abstract:

A nine year old, female spayed Great Dane presented to the Texas A&M Veterinary

Medical Teaching Hospital with a history of chronic neck and shoulder pain and progressive

hindlimb ataxia. MRI of the cervical spinal cord revealed multiple aggressive bone lesions of the

cervical vertebrae and right scapula, with lymphadenopathy of the right axillary, right superficial

cervical, sternal, and cranial mediastinal lymph nodes. Thoracic radiographs were consistent with

MRI findings. Ultrasound guided fine needle aspirates of lymph nodes and a right scapular mass

were prepared with modified Wright’s stain. Right superficial cervical lymph node cytologic

findings revealed a mildly reactive lymph node with moderate macrophagic inflammation and

poorly staining fungal hyphae. The fungal hyphae were septated, 5-6 um in diameter with varied

lengths and a thin 1-2 um non-staining wall, and some displayed branching. The right scapular

mass contained marked macrophagic and mild neutrophilic inflammation and fungal hyphae

morphologically similar to those found in the right superficial cervical lymph node. The

cytologic findings were consistent with disseminated fungal infection. An Aspergillus antigen

EIA for detection of Aspergillus galactomannan was negative. A panfungal PCR showed the

presence of Talaromyces species closely related to Talaromyces borbonicus. Fungi of the

Talaromyces genus have been reported to cause granulomatous arthritis and focal osteomyelitis

in two dogs, but this is the first case to demonstrate evidence of a severe multifocal presentation.

This patient was not known to be immunocompromised prior to clinical signs.