Disseminated Chrysosporium spp. infection was diagnosed in a German shepherd dog based on a positive fungal culture and cytological findings of intralesional fungi associated with granulomatous splenitis and neutrophilic lymphadenitis. The clinical presentation that could mimic a multicentric lymphoma, including markedly enlarged lymph nodes and a very abnormal splenic appearance on ultrasound makes this case even more atypical. The patient showed rapid clinical improvement on oral posaconazole and remains clinically stable ten months after diagnosis.
- Disseminated fungal infection;
- German shepherd dog
German shepherd dogs (GSD), particularly young to middle-aged females, are well-known for their predisposition to disseminated Aspergillus spp. infection  and . The familial tendency is further supported in this breed with the development of disseminated fungal disease in close relatives . A genetic predisposition leading to a deficient immune response to fungi, possibly related to immunoglobulin A (IgA) deficiency and/or dysfunction has been reported in this breed  and . However, the aetiology is likely multifactorial, involving dysfunction of both humoral and cell mediated immunity against Aspergillus spp. infection ,  and . Literature tends to suggest that GSD are also prone to other disseminated fungal infections caused by species such as Penicillium spp., Paecilomyces spp., Pseudallescheria boydii, Scytalidium spp., Scedosporium prolificans, and Chrysosporium spp., most of which would be classified as opportunistic ,  and .
Infection with Chrysosporium spp. is uncommon in both human and veterinary literature, being mostly described in reptiles. Information on clinical management is then quite variable and depends on the species involved, the extent of the disease (focal vs systemic involvement), and drug availability. Infection of a dog by Chrysosporium spp. has only be reported three times to date.
The difference in clinical presentation, ultrasound findings and long term treatment with posaconazole in the case described herein adds valuable information about the diversity of signs that Chrysosporium spp. infection can cause in dog and brings a new light on possible treatment. Indeed, to the author's knowledge, the successful use of posaconazole for Chrysosporium spp. infection has not yet been reported in humans or animals, making the description of this case unique.