Clinical cases

Cytological Diagnosis of Nocardiosis in a Cat

A clinical case of suspected nocardiosis in a cat: cytology of a mediastinal granuloma, Romanowsky negative staining, and bacterial acid-fastness.

🔬 Possible Nocardiosis Case in a Young Cat 🔬

Yesterday, I encountered an interesting, yet unconfirmed, case of nocardiosis in a young cat with pleural effusion.

Ultrasound-guided aspiration revealed a voluminous, nodular mass in the cranial mediastinum. Cytological examination showed a bacterial granuloma with characteristic morphological features:

✅ Gram-positive filamentous, branching rods within the cytoplasm of macrophages ✅ Negative Romanowsky staining ✅ Acid-fastness upon additional staining, indicating the possible presence of Nocardia spp.

🙏 Case kindly provided by - Olga Belozerova, clinical pathologist, head of the laboratory at the “Noah’s Ark” veterinary clinic, Kirov.