Both of these chews are worth stocking, but most dogs do not need both at once. Calmdogs® 8-in-1 Multivitamin Chews already contain a small amount of the same probiotic strain that anchors the dedicated Probiotic Chews, at a much lower dose. Buying both means paying twice for overlapping gut support at very different strengths, so the useful question is not "which is better" but "which one does my dog actually need."
This page sets out what each chew is actually for, where the two genuinely overlap, and how to pick one rather than defaulting to both.
What each chew is actually for
Calmdogs® Probiotic Chews are gut-specific. They contain a six-strain blend, including Bacillus subtilis (DE111), Lactobacillus acidophilus, L. plantarum, L. brevis, L. fermentum and Lactococcus lactis, at 2 billion CFU per chew. This is a targeted dose aimed squarely at supporting normal digestive function.
Calmdogs® 8-in-1 Daily Multivitamin Chews are broad daily nutrition, not a gut product. Alongside vitamins and minerals, they include glucosamine and chondroitin as part of everyday nutrition supporting normal joint function, omega-3s, and a small amount of Bacillus subtilis, 357 million CFU per chew, roughly a fifth of the total 2 billion CFU in the dedicated Probiotic Chews. The probiotic chew's blend total is what is published; how it divides between the six strains is not, so a strain-by-strain comparison is not possible.
The overlap, in plain numbers
| Chew | Bacillus subtilis | Total probiotic CFU | Price |
|---|---|---|---|
| Probiotic Chews | One of six strains | 2 billion CFU | £12.95 (120 chews) |
| 8-in-1 Multivitamin | Only strain present | 357 million CFU | £12.95 (120 chews) |
If your dog is already on the multivitamin and doing well generally, adding the probiotic chew on top is adding roughly six times the total CFU they are already getting, across six strains rather than one, rather than starting from nothing. That may still be the right call for a dog with a specific digestive issue, but it is worth knowing that is what you are doing.
How to choose
The probiotic chew is the better fit if your dog has an ongoing digestive sensitivity, is transitioning to new food, or your vet has specifically suggested a higher-dose, multi-strain probiotic.
The multivitamin is the better fit if you want broad daily nutritional support, your dog does not have a specific digestive complaint, and you are looking for one chew that covers general nutrition, joint ingredients and omega-3s together.
Both, together, make sense if your vet has recommended a higher combined probiotic dose alongside general daily nutrition. That is a reasonable use case, but it is a deliberate one, not a default.
Neither may be needed at all if your dog is well, eating a complete diet, and showing no digestive or nutritional concern. A supplement is for a specific need, not a routine addition by default.
Ingredients worth knowing before you buy
The multivitamin's glucosamine is sourced from shellfish, and its chondroitin is porcine in origin. Both matter if your dog has a shellfish sensitivity, or for households avoiding pork-derived ingredients for any reason. The probiotic chews use natural chicken flavouring and are not suitable for a chicken-avoidant dog.
If joint support is part of why you are considering the multivitamin, the amounts are worth knowing. The 8-in-1 provides 141.7 mg of glucosamine and 53.5 mg of chondroitin per chew, against 250 mg and 96.4 mg in our dedicated Active Hip & Joint Chews. Our guides to choosing a hip and joint supplement and to what glucosamine, chondroitin and MSM actually do both explain why the amount per chew matters more than the ingredient list.
Both chews are 2.5 g soft chews, 120 to a tub. Probiotic chew dosing is banded by weight: one chew daily up to 25 lbs (11 kg), two daily from 26 to 75 lbs (12 to 34 kg), and three daily over 75 lbs (35 kg). Start at half the stated amount for the first three to five days, then move to the full daily amount. The multivitamin is dosed at one to three chews daily by weight; the pack does not band this by weight range the way the probiotic chews do.
Complementary feeds, not medicine
Calmdogs® Probiotic Chews and 8-in-1 Multivitamin Chews are complementary feeds, not veterinary medicines. They do not diagnose, treat, cure or prevent any disease or condition.
If your dog has persistent diarrhoea, is losing weight, or is generally unwell, that is a reason to see a vet, not to reach for a tub. A supplement supports a dog that is already well; it is not the answer to a dog that is not.
Last bark
Most dogs need one of these chews, not both. Work out which job you actually need done, gut-specific support or broad daily nutrition, and choose on that basis rather than buying both to be safe.
Frequently Asked Questions
Here are some common questions customers may have about this topic.
What is the difference between a probiotic chew and a multivitamin chew for dogs?
A probiotic chew is gut-specific, built around a multi-strain blend at a high dose to support normal digestive function. A multivitamin chew is broad daily nutrition, covering vitamins, minerals and joint ingredients, with only a small probiotic component included as part of a wider formula.
Does the 8-in-1 multivitamin already contain a probiotic?
Yes. It contains Bacillus subtilis at 357 million CFU per chew, one strain at a fraction of the dose found in the dedicated Probiotic Chews, which provide six strains at 2 billion CFU per chew. The multivitamin's probiotic content is a minor part of a broad formula rather than its main purpose.
Do I need to give my dog both a probiotic and a multivitamin?
Usually not. Most dogs need one or the other, depending on whether the goal is gut-specific support or broad daily nutrition. Giving both makes sense mainly when a vet has recommended a higher combined probiotic dose alongside general nutrition, rather than as a routine default.
Are there allergens in the Calmdogs multivitamin or probiotic chews?
Yes. The multivitamin's glucosamine is sourced from shellfish and its chondroitin is porcine in origin, both relevant for dogs with a sensitivity or for households avoiding pork-derived ingredients. The probiotic chews use natural chicken flavouring and are not suitable for a chicken-avoidant dog.
When should I see a vet instead of choosing a supplement?
If your dog has persistent diarrhoea, is losing weight, or is generally unwell, see a vet rather than reaching for a supplement. These chews are complementary feeds intended to support a dog that is already well; they are not intended to diagnose, treat, cure or prevent any disease or condition.
