are the probiotics in your dog's chew already dead?.

the honest answer: quite often, yes - and it usually comes down to how the chew or kibble was made, not the brand's good intentions. live bacteria are fragile. push them through the heat used to make most dry dog food and the majority never reach the bag, let alone your dog's gut.

probiotics survive in a dog chew when two things line up. first, the strain is one of the few that can take heat and stomach acid - spore-forming bacillus species are the usual survivors. second, the maker guarantees the live count (the cfu) at the end of shelf life, not the day it was made. get either wrong and you are feeding an expensive placebo. here is how to tell the difference on a uk label.

why heat kills most probiotics

the majority of dry dog food is made by extrusion - ingredients cooked under steam and pressure at roughly 120°c, sometimes higher. published pet-food microbiology is blunt about what that does to live cultures: temperatures above about 45°c are detrimental to most probiotics, and delicate genera like lactobacillus and bifidobacterium largely degrade during processing.

that is why some brands spray a probiotic coating onto kibble after cooking. it is a genuine workaround, but the coating then has to survive months of storage, oxygen and moisture in the bag. in one study of a sprayed l. acidophilus food, survival was around 71% at the start and 63% by the study's end - so even the workaround loses ground over time.

which probiotics actually survive - spore-forming bacillus

a handful of species have a trick the others don't: they form spores. a spore is a tough dormant coat that shrugs off heat, acid and oxygen, then wakes up in the gut. bacillus subtilis and bacillus coagulans are the ones you'll see named on robust products, precisely because they hold up through manufacture and stomach transit.

the numbers back this up. in a 2023 characterisation of a bacillus coagulans strain, spore viability didn't change at all at 45°c or 75°c, and only dropped at 90°c. put through simulated stomach conditions - pepsin at pH 3, then bile salts - the spore counts showed no significant decrease. that is a different league from a bare lactic-acid strain.

what it faces	typical figure	what published data shows
kibble extrusion	~120°c, steam + pressure	most live bacteria destroyed
most probiotics (lactobacillus, bifidobacterium)	above ~45°c	detrimental; largely degrade
bacillus coagulans spores	45-75°c	no change in viability; drop only at 90°c
stomach transit	pH 3 + bile	spore counts hold; no significant decrease

cold-pressing helps, but "cooler" isn't "cold"

this is where how a chew is made starts to matter. cold-pressing runs far cooler than extrusion - academic figures for canine diets put extrusion up around 120 to 150°c, while cold-pressing works at much lower temperatures - which protects heat-sensitive ingredients that extrusion would flatten. that is a real advantage, and it is a big part of why the manufacturing method changes what's actually inside a supplement.

but be honest with yourself about it: cooler is not the same as cold. even a gentle press generates some heat, so the format alone doesn't guarantee a fragile strain will live. the strain choice still does the heavy lifting. a heat-stable spore-former in a cold-pressed chew is belt and braces; a delicate strain in the same chew is still a gamble.

how many cfu does a dog need?

there is no single official number, and any brand that quotes one as gospel is guessing. what does exist is regulation. in the uk and eu, a live strain sold to settle gut flora is a controlled feed additive: it has to be a specific, named, authorised strain, and the european food safety authority sets a minimum inclusion rate for it. for enterococcus faecium/lactis NCIMB 10415, for instance, that minimum is set at around 4.5 million cfu per kg of complete feed for dogs, under the category "gut flora stabilisers."

supplement daily doses commonly run into the billions, which sounds impressive on a pouch. but a bigger headline number means very little if those cfu are the wrong strain, or if they clocked off months ago in storage. strain identity and end-of-shelf-life survival tell you more than the size of the number.

decoding a uk label vs a us one

this trips people up. a uk or eu label often lists "millions" of a single named strain with an NCIMB or DSM code, while a us bottle might shout "billions" of a mixed blend. the smaller number can be the better product: a named, authorised strain at a declared count per kg tells you exactly what your dog is getting, whereas a big number attached to an unnamed blend tells you almost nothing.

two things to hunt for. one: a named strain, not just "probiotics" or "beneficial bacteria." two: cfu guaranteed at the end of shelf life or "best before," not "at time of manufacture" - because manufacture is the easy day. if you want the full walkthrough, reading a uk supplement label properly is worth ten minutes. and if you're weighing whether one daily chew can carry probiotics alongside everything else, our honest look at all-in-one supplements covers what one format can and can't hold.

what a probiotic can - and can't - do

within the rules, and within the honest evidence: heat-stable probiotics can help support normal digestion as part of a balanced diet. that is the whole claim, and we'd rather say it plainly than dress it up.

the ceiling on that claim is the science itself. a 2019 systematic review pooled 17 canine studies and found only "a very limited and possibly clinically unimportant effect" on digestive health, with most studies small and carrying a moderate-to-high risk of bias. so a good chew is a sensible daily support, not a medicine - and a strong candidate strain kept alive to the last day of shelf life is the version worth paying for.

the strain we use and the cfu we guarantee at end of shelf life are printed on our label, with the reasoning set out on our proof page. if you'd like the short version of the common questions, the faq covers them.