Intestinal Infections (Bacterial Enteritis) ------------------------------------------- Numerous bacteria can cause infections of the gastrointestinal tract of guinea pigs. Some of these bacteria are introduced on contaminated greens and vegetables or in contaminated water. Intestinal infections can manifest themselves as sudden death without prior signs, or as a more lengthy period of illness characterized by lethargy and marked weight loss. Diarrhea may or may not be noted in either case. A veterinarian will recommend aggressive antibiotic therapy and appropriate supportive care. A bacterial culture of the patient's stool and antibiotic sensitivity testing help the veterinarian select the appropriate antibiotic.