Guinea pigs are small, docile rodents, that must be approached with great care. Accurate evaluation of patient health status requires a thorough history, careful visual examination, and a detailed physical examination. Like most prey species, the guinea pig frequently hides signs of pain and illness. To improve clinical success, take measures to minimize stress by maintaining the animal in a quiet exam room and approaching the patient in a slow, quiet manner. The hospitalized guinea pig can also benefit greatly from the presence of a bonded cage mate. Monitor appetite and eliminations carefully in the guinea pig, and offer the same diet as fed in the patient’s home whenever possible as guinea pigs establish strong food preferences early in life.