Reasons for performing study Treatment of colic can be expensive and may exceed the owners’ financial limitations. This may result in premature euthanasia prior to treatment on rectifiable financial grounds rather than for welfare reasons. It is therefore important to ensure appropriate business model auditing to identify where costs may limit expected treatment options. Objectives This study investigated how the costs of treatment for equine colic at a single university referral hospital have changed over a 10-year period between 2003 and 2013. The aim was to analyse which costs have changed excessively or disproportionately between different treating services, consumables and professional fees, which may render treatment of colic financially prohibitive. Study design Retrospective study. Methods All charges billed against cases undergoing treatment for colic between 2003 and 2013 were accessed from hospital records. Horses were identified as having surgery or purely medical management. Charges were categorised by service (medicine, surgery, anaesthesia), type (consumable, livery, professional fee), and consumable type (e.g. NSAID, opiate, antibiotic, fluid therapy, lab fee, surgery consumables). Results There was a significant association between year and the frequency of medically and surgically treated colic (Chi-square test, P