Diarrhea Requires Prompt Treatment
See a vet immediately if your guinea pig has severe diarrhea, especially if your pet looks ill and is sitting with its coat puffed up. A black, foul-smelling watery mess indicates a very serious intestinal problem.
Milder forms of diarrhea (too many fresh fruits or vegetables or a change in feed) are also serious, require immediate treatment (generally replacing fresh vegetables with lots of timothy hay), and with no rapid improvement require a trip to the vet.
For diarrhea resulting from antibiotic use, consult your vet immediately. See treatment advice below (Antibiotic Associated Diarrhea).
Salana describes what tests your veterinarian may perform:
Fecal float: checks for parasites such as giardia and coccidia
Gram stain: shows the rough amount of both gram-negative and gram-positive bacteria (an overgrowth of gram-negative bacteria like Clostridium can cause diarrhea)
Culture: takes longer to get results, but will show what is there and to what it's sensitive
Subcutaneous fluids help restore hydration.
If parasites are present, an antibiotic like Flagyl (giardia), Panacur, or Albon (coccidia) may be prescribed.
If gram-negative bacteria are present, metronidazole (Flagyl) or Trimethoprim sulfa (bactrim) may help.
If yeast or other fungus are present, Nystatin may be prescribed.
If there is an overgrowth of clostridium difficile, Bio-Sponge may help prevent toxicity by absorbing toxins and bacteria.
To reestablish a good balance of gut flora, use a Probiotic. Especially helpful may be caecal pellets from a healthy pig. Avoid yogurt and milk products. Hand feed to keep food moving through the system. See also Antibiotic Associated Diarrhea treatment suggestions below. Syringe fluids, as diarrhea is very dehydrating. A vet can give subcutaneous fluids. Simethicone can help with mild gas. Coccidia can cause excessive gas. A second fecal float may find coccidia not initially present.
See also: Seeking Advice On Diarrhea on Guinea Lynx Forums.
Antibiotic Associated Diarrhea
One of the most serious mistakes an inexperienced veterinarian can make is to prescribe a deadly antibiotic such as amoxicillin to treat a bacterial infection in a guinea pig.Brown and Rosenthal describe antibiotic associated diarrhea in guinea pigs, a significant danger when using Gram-positive spectrum oral antibiotics, which can "seriously alter the sensitive balance of bacterial flora in the cecum." As a result, bacteria like clostridia spp. and escherichia coli can overgrow as the normal flora is killed off.
The enterotoxins produced by these bacteria are absorbed systemically. "The result of the cecal dysbiosis and enterotoxin production is diarrhea, systemic toxicosis and ultimately death."
They describe the PLACE rule as a rough guideline for antibiotics to avoid. [PLACE -- penicillin, lincomycin, ampicillin, amoxicillin, cephalosporins, clindamycin, erythromycin] See Dangerous Medications for a more complete list of medications that have caused serious problems and sometimes death when used on guinea pigs.
Brown and Rosenthal note that the most commonly prescribed antibiotics (baytril, bactrim, and chloramphenicol) are "rarely associated with GI disturbance" in guinea pigs.
Treatment for antibiotic associated diarrhea:
DISCONTINUE THE ANTIBIOTIC CAUSING DIARRHEA IMMEDIATELY.
If the animal is still eating and acting normally:
Provide grass hay (helps to restore gut motility)
Remove all grain based foods (high levels of starch encourage the grown of E. coli and Clostridium spp.)
Hydrate via subcutaneous fluids
Supplement with vitamin C tablets or liquid (30-50mg/kg q12-24h) (besides being a nutritional requirement, it may "slow the absorption of enterotoxins through the cecal wall")
When the droppings are firm, discontinue C supplement and give fresh dark leafy greens high in C. Pellets can lose their vitamin C so supplementation with a natural source is important.
If the guinea pig is not eating, much more aggressive therapy will be required. Brown and Rosenthal also advise fecal Gram stains to check for clostridial spores if the diarrhea persists or the animal goes downhill. If found, treat with metronidazole (flagyl) @ 20mg/kg PO q12h. If no clostridial spores are present, do a fecal culture and treat with baytril while waiting for results. Give fluids IV SC or IO if the animal is systemically ill. Guinea pigs with profuse watery diarrhea have a poor prognosis.
Equine Bio-Sponge, which contains Di-tri-octahedral smectite, is reasonably priced and very effective.
"Bio-Sponge is an intestinal protectant designed to help support healthy intestinal function. Bio-Sponge has substantial capacity to adsorb and absorb toxins, viruses, bacteria and free radicals. A university study showed that Bio-Sponge™ adsorbed 99% of clostridium difficile and clostridium perfringens toxins in vitro."
Dosage information received via email from Allyson at Platinum Performance, Inc. who consulted their staff nutritionist:
Guinea Pigs 600-900 grams administer between 0.4cc-0.6cc total daily, split into 2-4 feedings.
Guinea Pigs 950-1400 grams administer between 0.7cc-1.0cc total daily, split into 2-4 feedings.
See also: Abstract Regarding Di-Tri-Octahedral Smectite and Production of Enterotoxins in Horses
CONCLUSIONS: Di-tri-octahedral smectite possesses the ability to bind C. difficile toxins A and B, C. perfringens enterotoxin and endotoxin in vivo while having no effect on bacterial growth or the action of metronidazole.
See also: Antibiotic Associated Enterotoxemia in Guinea Pigs by Dr. Nakamura. His article describes treatment of enterotoximia caused by unsafe antibiotics.