Jarrow Brand S. Boulardii is the most commonly locally available S. Boulardii supplement (in the U.S.). It is usually sold as S. Boulardii + MOS. “MOS” are mannan-oligosaccharides, a medium that promotes utilization of the probiotic in the intestines. It seems the MOS makes the product bitter, as most kitties will eat “plain” S. boulardii (Nutricology, A.O.R. and Renew Life brands listed here) when sprinkled on or mixed into foods – but not the S. Boulardii with MOS. This is not to say this product cannot be used, it can, but it usually needs to be syringed or pilled into the cat. If you can find an S. boulardii supplement at 5 billion CFU without MOS (there are plenty of other brand options, at least online), you may find it easier to use if your cat is not inappetent. Jarrow does have a product available in premeasured packets rather than capsules. If available, these packets will make it a little easier to use for emergency treatment if you have or can purchase small (size 3) empty capsules. Some cats eat the Jarrow S boulardii mixed into a bit of Beechnut baby food and fed as a “treat.”
For emergency “stop diarrhea” use, it is recommended to purchase size 3 empty capsules. Fill 10 or so of these, and administer them to your cat every 2 hours. This often stops diarrhea within 24 – 48 hours, other than when diarrhea is caused by another disease that requires treatment (low B12, exocrine pancreatic insufficiency, hyperthyroidism, as examples). This “loading dose” can be continued for three to four days if necessary. It is NOT necessary to use this approach, it can be given at “therapeutic” doses twice a day (and doubled if you see improvement in stool but diarrhea or soft cow patty stools have not resolved).
NOTE: IF USE OF S BOULARDII MAKES DIARRHEA WORSE, STOP. Give kitty a break for 3 days, and start over at a MUCH smaller amount, and very slowly work up to the therapeutic dose. If even the small amount makes diarrhea worse, your cat is likely sensitive to yeasts and this cannot be given.
When the diarrhea has resolved with use of the emergency stop treatment protocol, begin use of S. boulardii at the therapeutic dose level (2.5 billion CFU twice daily) and continue for at least one week and up to one month; then adjust dose to the maintenance level (half that), or use the Nexabiotic 21-strain probiotic for maintenance. If stools soften, resume use of S. boulardii at the therapeutic dose as needed. Given its role in improving performance of bacterial probiotics and its anti-inflammatory properties, the use of S boulardii at maintenance levels can be continued indefinitely along with a bacterial probiotic.