[Oceanside]

Probiotic strains can vary quite a bit in terms of their resilience and the conditions they survive in. Most beneficial probiotic strains are quite fragile, so as SRW said, it’s often said that probiotics added to a dry dog food are likely dead on arrival — think of temperature changes, exposure to light especially if the bag is not shielded, changes in humidity, etc. during shipping and storage of a dry food.

That said, there are some strains that are thought to be more resilient, including some strains that are considered heat resistant. Some kibble manufacturers add a heat-resistant strain to the formula before extrusion, while other manufacturers will spray more fragile strains onto the finished kibble. I have seen many confident claims from many kibble manufacturers (which often contradict each other), yet I haven’t come across much scientific proof any which way.

The way I look at it is that the dose of probiotic listed on kibble products (which is the amount present at time of production), is such a small amount that even if most of it is still alive at the time of consumption, I would not bank on it doing anything. If the food has it, great, if not, fine. If you want a probiotic, you’ll need to give a good one separately anyway.

PPP lists 600 million CFU of bacillus coagulans (which is the most commonly used strain for pet food products) per pound of kibble (for ease of calculation let’s say that’s 1 day worth even though I think it’s more). It’s generally said that you need a few billion CFU to achieve any sort of result with a probiotic (not getting into the reasons for use here, just speaking generally). For comparison’s sake, I use a probiotic that has 14 strains (not just 1) with a total dose (for a golden retriever-sized dog) that adds up to about 100 billion CFU, so 167x the dose. That probiotic is packaged in dark tinted glass with a moisture-absorbing pad inside, and it must be kept at room temp and used within 6 months. Overkill, sure, but my point is that any probiotic in a dry pet food, if it’s there, does not have variety, is not dosed high enough, nor can it possibly be handled as carefully as a stand alone therapeutic product, thus the debate over how much probiotic will survive in kibble doesn’t matter much either way.