case_images: PMC10759777_01
case_images: Gross changes in horse lungs. White pin-point abscesses (arrowheads) and petechial hemorrhages (arrows) in lung cut section from diaphragmatic lobe, (bar = 5.00 cm).
case_images: vrf-14-685-g001.jpg
case_images: PMC10759777_01_vrf-14-685-g001.jpg
case_images: F1
case_images: The lungs were consolidated, meaty, and contained diffuse petechial hemorrhages together with multi-focal white, round, firm, and pin-point micro-abscess (Fig. 1).
case_images: A) Intra-alveolar fibrin accumulations (arrowheads) and abscess formation (arrow), (H&E staining; bar = 50.00 microm),  B) Peri-vascular lymphocytic infiltration (arrow) and fibrosis, (H&E staining; bar = 20.00 microm), C) Thrombus formation in capillaries (arrows) and a vein with canalization (arrowhead), (H&E staining; bar = 50.00 microm), and D) Gram-positive coccoid microorganisms in neutrophils (Gram staining; bar = 10.00 microm)
case_images: vrf-14-685-g002.jpg
case_images: PMC10759777_01_vrf-14-685-g002.jpg
case_images: F2
case_images: The main histopathological lesion was sub-acute to chronic fibrinosuppurative pneumonia characterized by fibrin deposits and neutrophilic infiltrations (Fig. 2A). The vasculitis characterized by peri-vascular edema and infiltrations were also observed (Fig. 2B). Partial or complete thrombi were formed in the pulmonary, nasal and tracheal mucosae (Fig. 2C). Gram staining showed intra-lesional Gram-positive coccoid microorganisms phagocytized by neutrophils (Fig. 2D) and Gram-negative bacilli.