Purina publishes its own comparison material explaining how FortiFlora PRO Synbiotic Action differs from the original FortiFlora powder, so the two get compared constantly by owners trying to pick a line. On paper they're close: the same 100 million CFU figure, the same single strain (Enterococcus faecium SF68), and identical canine study counts. The real difference is smaller than it looks — PRO Synbiotic adds psyllium husk fiber that the original formula doesn't have, and only the original shows up with an Amazon listing in our data.
Not veterinary advice. Each claim above is backed by the label row or study linked in the full table below.
Stronger value rule: more strain-named organisms, CFU guaranteed through expiry over at-manufacture, and more canine RCTs each count as stronger. Raw CFU count alone never does.
Tagged from public posts mentioning either product. Counts, not opinions.
There's no real reason to combine them — both are built on the exact same strain, Enterococcus faecium SF68, so giving both would mostly mean doubling the dose of one organism rather than adding anything new. We didn't find a study that tested stacking them, either.
The matching CFU number isn't really the story here, since neither label states whether that count is guaranteed through expiry or only at manufacture. What they do share is the same strain and the same canine study count, so the practical difference comes down to the added psyllium husk fiber in the PRO Synbiotic version, not the CFU figure.
Original FortiFlora has an Amazon ASIN (B001650NNW) in our data. FortiFlora PRO Synbiotic Action doesn't, so it's likely only available through veterinary or Purina ordering channels. We don't have pricing to compare directly.