Sensitivity of Guinea Pigs to Certain Antibiotics

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Guinea pigs as a group are unusually sensitive to certain

antibiotics, whether they are given orally or by injection.

Potentially harmful antibiotics include ampicillin, penicillin,

bacitracin, erythromycin, lincomycin, gentamicin,

clindamycin, streptomycin, vancomycin and sometimes

tetraycline.  Interestingly, even certain antibiotics used

topically may produce lethal effects.



The major way in which certain antibiotics cause reactions is by

altering the normal microbial balance within the gastrointestinal

tract.  Once the normal intestinal microfloral balance has been

upset, certain bacteria multiply to abnormally large numbers.

The multiplying bacteria produce harmful chemicals that can have

lethal effects.



Certain antibiotics (streptomycin, dihydrostreptomycin) are

directly toxic and do not alter the microbial balance within the

gastrointestinal tract.  These antibiotics should never be used

in guinea pigs.



Though injectable antibiotics can cause the problems described

above, oral antibiotics are more often associated with them.

Antibiotics should never be given to guinea pigs unless they are

prescribed by a veterinarian.  If oral or injectable antibiotics

are prescribed, 2 1/2 cc (1/2 teaspoon) of plain, white yogurt

should be given orally to the treated animal morning and evening

for the duration of the antibiotic therapy and for an additional

5-7 days afterward.  Yogurt helps replace those beneficial

intestinal bacteria that often perish during antibiotic

treatment.