Cat: Thorax (pleural space) and lungs. Pleural effusion, serous, acute with wet/edematous and congested lungs due to acute congestive heart failure (hypertrophic cardiomyopathy)..

Cat: Spleen. Moderate to marked splenomegaly due to congestion.

Cat: Heart. Cardiomegaly with biventricular dilation (end-stage hypertrophic cardiomyopathy).

Cat: Distal aorta. Aortic thromboembolus (saddle thrombus) secondary to hypertrophic cardiomyopathy.

Cat: Descending aorta and left renal artery. Saddle thrombosis-intraluminal thrombus, focal, subacute with luminal occlusion.