Disseminated blastomycosis in a 1-year-old, male golden retriever-poodle crossbred dog

Abstract

A 1-year-old male golden retriever-poodle crossbred dog was brought to a veterinary clinic with a 1-month travel history to Muskoka, Ontario and a 1-week history of left eye irritation and ocular discharge. Ophthalmic examination and blood analysis revealed bilateral uveitis with a normal complete blood (cell) count and biochemistry panel. Symptomatic treatment was administered with no improvement observed and the dog returned 2 weeks later for assessment of a draining swelling of the left hind 4th digit. Clinical examination of thoracic radiographs and abdominal ultrasound showed evidence of disseminated blastomycosis characterized by pulmonary lesions, and multifocal lymphadenopathy. Biopsy of the draining lesion and cytological examination of an enlarged lymph node established diagnosis. The dog was started on a standard antifungal treatment protocol (itraconazole) but returned after 11 d of treatment with neurological signs including ataxia, paraparesis, left head tilt, and compulsive turning. Humane euthanasia was chosen and the diagnosis was confirmed at postmortem examination.

Figure 1

A — Right lateral thoracic radiograph with evidence of multiple nodular increased opacities in the perihilar region. Mild interstitial pattern within left cranial and caudal lung lobes. B — Ventrodorsal thoracic radiograph with evidence of a widened mediastinal silhouette with increased opacity in the perihilar region. Focal irregular nodule of increased opacity within the right cranial lung lobe (arrow). Mild interstitial pattern throughout all lung lobes.

Figure 2

A — Photograph of thoracic viscera on postmortem. a — Focal, 3.5-cm raised, white-tan, well-demarcated, firm circular nodule within the right cranial lung lobe. b — Generalized multifocal, 1 to 2-mm raised, white-tan, well-demarcated, firm circular-coalescing nodules throughout all lung lobes. c–e — Enlarged tracheobronchial and mediastinal lymph nodes. B — Stained impression smear of right cranial lung lobe nodule (a). Evidence of refractile, deeply basophilic, fungal organisms with a thick cell wall throughout sample with occasional broad-based budding (arrows).