Pulmonary cryptococcosis in a Warmblood mare

Pulmonary cryptococcosis with an endobronchial cryptococcoma in a Warmblood mare

Can Vet J. 2026 Sep 1;67(9):970-975. eCollection 2026 Sep.
Authors
Eun-Bee Lee 1 , Yong-Woo Chun 1 , Jong-Pil Seo 1
Affiliation

1 College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju-City, Jejudo 63243, Republic of Korea (Lee, Seo); J&C Equine Animal Medical Center, Icheon-si, Gyeonggi-do, Republic of Korea (Chun).

PMID: 42699316
PMCID: PMC13544533

Abstract
in English, French

This report describes pulmonary cryptococcosis with a large endobronchial cryptococcoma in an 8-year-old Warmblood mare. The mare was presented initially with fever and lethargy, and clinical signs typical of bacterial pneumonia. Markedly elevated serum amyloid A (SAA) concentrations indicated a severe systemic inflammatory response. Over a period of 6 wk, the condition progressively worsened and was refractory to multiple courses of broad-spectrum antimicrobial therapy as administered in a field setting. Diagnostic imaging following referral revealed extensive consolidation of the left lung and multiple nodular lesions. Endoscopy identified a large granulomatous mass nearly completely occluding the left mainstem bronchus. Histopathologic examination of biopsy samples from the mass and lung parenchyma revealed a severe pyogranulomatous inflammation composed of numerous encapsulated, budding yeast organisms (8.5 to 12.5 μm in diameter with a 2- to 3-μm thick capsule) morphologically pathognomonic for Cryptococcus spp. Due to extensive, irreversible lung damage and poor prognosis, euthanasia was elected. Key clinical message: This case serves as a reminder to include fungal pathogens such as Cryptococcus in the differential diagnosis of severe and non-responsive pneumonia in horses.

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• This topic was modified 23 minutes ago by Robert Oglesby DVM.