The best results from surgery come from following an appropriate plan, based on an accurate preoperative diagnosis. This plan includes a thorough evaluation and investigation of the presenting complaint and any other concurrent disease an animal may have. Many animals requiring surgery in general practice are young and healthy and are presented for routine ovariohysterectomy or castration. After a thorough history, complete physical examination, evaluation for possible congenital abnormalities and, if indicated, a minimum database (including packed cell volume (PVC), total protein, evaluation of urea and blood glucose level), the majority of these animals require little if any stabilization prior to anaesthesia and routine surgery. Intravenous access, careful endotracheal intubation, strict attention to asepsis and meticulous surgical technique all ensure a successful surgical outcome. This chapter looks at Gastrointestinal diseases; Haemoperitoneum; Hepatic disease; Respiratory system; Cardiovascular system; Urogenital system; Orthopaedic surgical conditions; and Endocrine diseases. Techniques for Placement of a trochar chest drain; Chest drain placement using haemostat forceps and Placement of a small-bore wire-guided chest drain are included.