Splenic epidermoid cysts are rare congenital lesions which usually present insidiously with non-specific symptoms such as dull left upper quadrant pain, or as incidental findings on clinical examination. We present a chicken breeder who presented as an emergency with a tender left upper quadrant mass and septicaemia secondary to zoonotic infection of a primary splenic cyst with Salmonella enteritidis. The cystic nature of the swelling was confirmed by ultrasound and the anatomy assessed with computed tomography. She was aggressively resuscitated and underwent laparotomy and splenectomy, after which she made an uncomplicated recovery. The importance of early diagnosis and surgical treatment is discussed, together with the measures required as prophylaxis against overwhelming post-splenectomy sepsis.