Antibiotic-associated enterotoxemia is a condition in which the use of antibiotics results in a disruption of the normal intestinal flora. Pathogenic (disease causing) bacteria such as Clostridial organisms, overpopulate the intestinal tract and produce bacterial toxins, or enterotoxins, that cause blood poisoning and diarrhea.
Guinea pigs are herbivores (strict vegetarians) and have a similar digestive tract to horses, rabbits and chinchillas. Their digestive tract is specialized in order to help breakdown and digest plant materials. Most mammalian species do not have the digestive enzymes that are required to breakdown cellulose which is the main structural building block of plant material.
In order to accomplish this, guinea pigs have a storage organ called the cecum which is a pocket off of the intestines. This structure is equivalent to a human's appendix except that it is proportionally much larger in the guinea pig. The cecum serves as a storage organ that allows bacteria, digestive enzymes, and ingested food time to mix and breakdown the tough cellulose.
Periodically, the cecum empties the mixture into the intestinal tract where nutrients can be absorbed. Some nutrients (such as Vitamin B) are not absorbed until they go through a second pass, which is accomplished through copraphagy (eating of feces). Coprophagy is important and normal for guinea pigs.
Bacteria are important for the proper function of the digestive tract. The bacteria live in the intestinal tract in a symbiotic relationship, which means it benefits both the bacteria and the guinea pig, and any imbalance in the normal intestinal gut flora (bacteria found in the intestines) can have severe repercussions.
Antibiotics are often required to treat infections in guinea pigs. Their function is to kill or stop bacteria from reproducing. Because of the way they work, each antibiotic has a different spectrum or range of different types of bacteria it will affect. Using antibiotics can be dangerous because it can eliminate the normal intestinal flora and allow pathogenic (harmful) bacteria to flourish in its place, resulting in enterotoxemia.
What To Watch For
Typically, clinical signs if enterotoxemia begin 6 to 48 hours after beginning antibiotics. Common antibiotics that cause this condition are penicillins (amoxicillin and ampicillin), lincosamides (lincomycin and clindamycin), aminoglycosides (gentocin, amikacin), macrolides (erythromycin), and sometimes tetracyclines and cephalosporins (cephalexin, cefadrops).
Guinea pigs generally succumb because of the toxemia (toxins in the bloodstream) and severe diarrhea causing dehydration and electrolyte imbalances that result in general organ failure. Also, due to the disruption of the intestinal normal defense, bacteria invade the blood stream and cause septicemia (systemic infection). Prognosis is very guarded. This is a very serious condition and most guinea pigs die despite aggressive therapy.
Your veterinarian will probably recommend the following tests to aid in the diagnosis of enterotexemia: