Management of sudden onset of bradycardia and arterial hypotension during phaeochromocytoma excision in a dog – a case report

An 11-year-old female spayed Shih Tzu was presented with a history of weight loss, lethargy and a heart murmur. After extensive diagnostics, an adrenal mass was discovered, suspected to be a pheochromocytoma, and surgical excision was planned. During anesthesia, no signs of catecholamine discharge were seen. However, sudden bradycardia and hypotension occurred, necessitating anticholinergic therapy. Such therapy is usually contraindicated in patients with pheochromocytoma due to the risk of significant tachycardia, cardiac arrhythmias, and arterial hypertension. No adverse effects were noted, and the dog recovered uneventfully from the procedure.