Forelimb arterial tumour thromboembolism with concurrent venous thrombosis and skeletal‐muscle metastases from primary pulmonary carcinoma in a cat

A 10-year-old, neutered, male, domestic shorthair cat was referred with a 3-day history of hyporexia and dyspnoea. Neurological examination revealed acute right forelimb monoplegia without deep pain and ipsilateral hindlimb monoparesis. The right brachial pulse was absent, with marked limb hypothermia and a reduced ipsilateral tarsal pulse. Echocardiography was unremarkable. Whole-body contrast-enhanced computed tomography angiography identified a cavitated mass involving the caudal lung lobes, a filling defect at the right pulmonary artery bifurcation, and arterial thromboembolism of the right subclavian/axillary arteries. Concurrent thromboses were observed in the pre-renal caudal vena cava and right iliac/femoral veins. Additional findings included ischaemic myopathy of the right forelimb and two rim-enhancing muscular nodules. Cytology confirmed pulmonary carcinoma with muscular metastases. Palliative therapy was instituted at the owner's request, but the patient's condition deteriorated rapidly, leading to euthanasia. This report describes a rare presentation of multifocal arterial tumour thromboembolism with skeletal muscl metastases in a cat.