Gastroesophageal reflux (GER), where stomach contents pass into the esophagus, is a known complication in dogs undergoing anesthesia. Although rare, severe complications can result due to GER, such as pneumonia or stricture of the esophagus. Therefore, several previous studies have investigated ways to reduce this phenomenon in the peri-anesthetic period. Nausea and vomiting are a common complication in humans after they undergo anesthesia, and due to concerns for this phenomenon also happening in dogs, many practitioners may administer drugs to prevent vomiting before dogs undergo anesthesia. However, a previous study in dogs found that those that vomited after receiving premedication with sedative and analgesic drugs before the induction of general anesthesia were less likely to experience GER. Therefore, the purpose of this study is to evaluate whether giving maropitant (a drug to prevent vomiting) before premedication is associated with a larger stomach volume and a higher incidence of GER under anesthesia. Dogs in this study will be assigned to three groups where they either get maropitant before premedication, after induction of anesthesia, or not at all. They will be assessed for GER while under anesthesia by placement of a probe in their esophagus. Ultrasound will also be used to evaluate the size and motility of the stomach in these dogs during and after anesthesia. The dogs will be followed after anesthesia to monitor for gastrointestinal signs or associated complications. We hypothesize that dogs that receive maropitant before premedication will experience more GER while those that receive maropitant after the induction of anesthesia will not have an increased risk of GER but will still benefit from maropitant therapy in the recovery period.