P‐60 Hypercalcaemia associated with disseminated Lagenidium spp. infection in a dog: case report

Abstract

Oomycetes such as Pythium insidiosum are soil‐ or water‐dwelling organisms that belong to the Kingdom Stramenopila. Recently, a member of the genus Lagenidium has been recognized as a second canine pathogen in the class Oomycetes, causing multifocal ulcerative cutaneous lesions, subcutaneous pyogranulomatous nodules and draining tracts, often with dissemination to lymph nodes and abdominal great vessels. This report describes the clinical, cytologic and pathologic features of Lagenidium spp. infection associated with hypercalcaemia in a dog. A 1.5‐year‐old female border collie was referred for evaluation of progressive ulcerative skin lesions. Physical examination revealed pyrexia, generalized lymphadenopathy and multiple draining tracts, nodules and ulcers with eschars involving the distal aspect of all four limbs. Serum biochemical analysis revealed hyperglobulinaemia, hypoalbuminaemia and hypercalcaemia. Cytologic evaluation of fine‐needle aspirates from lymph nodes and cutaneous lesions revealed pyogranulomatous inflammation surrounding multiple poorly staining broad (14–21 μm) hyphae. These right‐angle branching hyphae were infrequently septate with irregular nonparallel walls. Thoracic radiography was normal. Abdominal ultrasonography showed no great vessel involvement. Euthanasia was elected, and necropsy revealed severe pyogranulomatous dermatitis and lymphadenitis involving the prescapular, popliteal, superficial inguinal, gastric, lumbar and external iliac lymph nodes. Histologically, all lesions were characterized by severe pyogranulomatous inflammation centred around broad, poorly septate hyphae. Parathyroid glands were histologically normal. Granulomatous disease associated with oomycosis should be considered as a differential diagnosis for hypercalcemia in canine patients with subcutaneous nodules or ulcerative dermatopathy associated with lymphadenopathy. Funding: Self‐funded.