A 30 gram syringe containing a source of live, naturally-occurring probiotic microorganisms. Directions for use: foals û 10 grams on day of birth, repeat on day 4 and at weaning. Horses û 30 grams 8 to 12 hours prior to anticipated adverse conditions or changes. Guaranteed total viable lactic acid-producing bacteria 10 million colony forming units (CFU) per gram.