Mini Case Report: Presumptive feline blastomycosis

As summer approaches and our small animal companions venture farther into the great outdoors with us, exposure to environmental hazards, including microorganisms, increases. Several cases of canine and feline fungal and protistan infections were identified by histopathology over the last several months. Exposure to this microorganism likely occurred in the summer or fall.

One adult domestic longhaired cat presented to the clinic with a facial mass and enlarged regional lymph nodes. Microscopically, sections of the mass and lymph node revealed widespread necrosis admixed with severe suppurative inflammation. Interspersed throughout were numerous 20-40 um thin-walled yeast with a clear halo around a central basophilic or vacuolated structure. The yeast exhibited both broad-based and narrow-based budding (Figures 1, 2). A special histochemical stain for Cryptococcus spp. was negative, and the presumptive diagnosis was systemic blastomycosis.

This case report and others are also available in the Spring 2019 newsletter.

Heidi Pecoraro, DVM, PhD, DACVP

Figure 1
Figure 2