Objective: To evaluate the impact of postdischarge surveillance on surgical site infection (SSI) diagnosis. Study design: Prospective enrollment with retrospective case reviewSample Population: Dogs and cats (n 5 1271) undergoing surgery April 2012-November 2013. Methods:The medical record of each animal was reviewed and a 30-day follow-up questionnaire was sent to each pet owner. A standardized definition of SSI was used to identify all animals with SSI. The method of SSI detection was recorded as: representation to the hospital, scheduled recheck, questionnaire, communication with the referring veterinarian, or a combination of the above.Results: SSI was identified in 36 (2.83%) of the 1271 animals included. All SSIs were diagnosed after discharge from the hospital. Seven of the 36 animals with SSI were diagnosed at re-presentation to the hospital, 5/36 at scheduled recheck, 10/36 on questionnaire, 10/36 at re-presentation to the hospital AND on questionnaire, and 4/ 36 on communication with referring veterinarian. Of the diagnosed SSIs, 72.2% were documented in the medical record. Therefore, without active postdischarge surveillance, 10/36 SSIs (27.8%) would have gone unknown to surgeons at our institution. Conclusion:Understanding the incidence of SSI with feedback to surgeons is an important aspect of an infection control program and has been shown to reduce SSI risks. Without active postoperative surveillance, 27.8% of SSIs would have gone unknown to surgeons. Implementing active surveillance will allow accurate reporting of incidence of SSIs in veterinary hospitals.