The best probiotics for dogs in the UK, scored on four things

The strongest case for buying a dedicated probiotic: six times the bacteria of number one, and a label that prints a figure next to every part of the blend.

• 3 billion CFU plus 100 million from a second named strain
• FOS, GOS and the postbiotic blend all printed in mg per chew
• A clear weight table, down to a half chew for the smallest dogs
• 30 chews a tub, and a dog over 34 kg takes three a day, so a tub is ten days
• 30 days to decide, and the returns page asks for unused and sealed units
• The 60 day guarantee is on their Joint Care Chews, not on this one

3 billion CFU Bacillus velezensis and 100 million Enterococcus faecium per 4 g chew, with FOS 100 mg, GOS 100 mg and 75 mg of yeast postbiotic.

The widest stocked of the five and the easiest to restock, with a label that prints its figures. What it does not do is anything outside the gut.

• 1 billion CFU from a named strain, with EpiCor 105 mg and FOS 500 mg per chew
• In 457 Pets at Home stores as well as online, so no waiting on a delivery
• A satisfaction guarantee that also covers a dog that simply refuses them
• Gut and immunity only, so joints and skin are a separate purchase
• The guarantee has no stated number of days to work with
• One to three chews depending on weight, so the pack size moves with the dog

1 billion CFU Bacillus velezensis (Calsporin), EpiCor 105 mg, FOS 500 mg and 19.5% pumpkin. The British formula differs from the American one.

The broadest of the four challengers, and the only powder here. Everything is declared per kilo of product, so you do the arithmetic yourself.

• Gut, skin and coat, plus vitamins, trace elements and L-tryptophan
• A named strain with a published count
• A five band feeding guide printed on the pack
• Figures are per kilo of powder, not per serve, so a serve is a calculation
• A teaspoon by weight, and a fussy dog can eat around a powder
• The money back applies to online orders only, with no period given

Bacillus velezensis DSM 15544 at 6 x 10¹⁰ CFU per kg, chicory root 15%, fish oil 1%, L-tryptophan 1,000 mg/kg and lysine 2,000 mg/kg.

The brand a British vet practice is most likely to stock, and the one that tells you least about what is in the tablet.

• A guarantee with a number on it: six weeks, with published terms
• The most widely recommended supplement brand in British practices
• One tablet format, easy to give alongside food
• No bacteria count, no strain names and no amounts published on the product page
• Gut only, so joints and skin are a separate product from the same brand
• Six weeks is about the point at which you would first notice a gut change

Bacteria count, strains and ingredient amounts: not published, checked again on 22 September 2026.