A 19 year-old male castrated American Quarter horse presented to Cornell University's Large Animal Medicine Service for tachycardia, fever, and nasal discharge. The patient was depressed and lethargic. Physical examination revealed a tachycardia of 96 beats per minute, tachypnea of 40 breaths per minute, elevated rectal temperature of 101.9 F, and hyperemic mucous membranes. A nasogastric tube was passed which produced 10 L of net reflux. Abdominal and thoracic ultrasound revealed thickening and distention of the small intestine and significant craniovcntral and middle lung field consolidation, respectively. Analysis of an abdominocentesis sample was not consistent with a surgical lesion (the fluid was straw-colored and the peritoneal lactate was similar to peripheral blood lactate). Hematology revealed hemoconcentration and evidence of severe endotoxemia. Based on clinical signs on presentation and diagnostic procedures, the patient was diagnosed with anterior enteritis with suspected aspiration pneumonia secondary to spontaneous reflux. This case report will explore the etiology of anterior enteritis and discuss treatment options available and supportive care necessary to maintain these patients.