
Probiotics for Dogs and Cats: What Do They Do and Does Your Pet Really Need Them?
, by Michael van Wassem, 7 min reading time

, by Michael van Wassem, 7 min reading time
Probiotics for dogs and cats: what they do, when they're useful, and what to look for when choosing a supplement.
You've probably seen it on the supplement shelf: tubs and sachets labelled "probiotics for dogs" or "probiotics for cats". Manufacturers promise better digestion, stronger immunity and a shinier coat. But what are probiotics exactly, do they actually work, and when does your pet need them?
Probiotics are live, "good" bacteria that support the balance of the gut flora. In dogs and cats, they can be useful during or after a course of antibiotics, for stress-sensitive animals, during a food transition, or for temporary, mild digestive upset. They're not a miracle cure: for persistent diarrhoea, vomiting, weight loss or lethargy, a vet visit always comes first, not a supplement.
Probiotics are live micro-organisms — usually bacterial strains such as Enterococcus faecium, Lactobacillus or Bifidobacterium species — that, given in sufficient quantity, can have a beneficial effect on the gut flora. They differ from prebiotics, which are dietary fibres (such as FOS or inulin) that feed the animal's own good bacteria in the gut. Many supplements combine both, and are then called synbiotics.
Important to know: human probiotics aren't automatically suitable for dogs or cats. The gut flora of each species is different, which is why most pet supplements contain strains specifically tested on dogs or cats.
The gut of dogs and cats hosts an enormous diversity of bacteria that together form the microbiome. This microbiome helps digest food, produces certain vitamins, and helps regulate the immune system — a large part of the body's defences sits in and around the gut wall. When that balance is disrupted, for example by medication, stress or a sudden change of food, "unwanted" bacteria can temporarily gain the upper hand. This often shows up as soft stools, gas or a reduced appetite. Probiotics supply extra good bacteria to help restore that balance more quickly.
Probiotics are most often recommended in the following situations:
Interest in the pet microbiome has grown considerably in recent years, including within veterinary medicine. Research in dogs and cats shows that certain, well-studied strains (such as Enterococcus faecium SF68) may contribute to a shorter recovery time from acute diarrhoea and to more stable stools during stressful periods. Veterinary nutrition organisations such as the WSAVA (World Small Animal Veterinary Association) recognise the importance of a healthy microbiome, but also stress that not every product is the same: the effect depends heavily on the specific bacterial strain, dosage and quality of the supplement.
To be fair: for many of the health claims on packaging — such as "shinier coat" or "stronger immunity" — the scientific evidence in companion animals is still limited or comes mainly from small-scale studies. That doesn't mean probiotics are useless, but healthy scepticism towards big promises is warranted. If you're unsure whether your dog or cat would benefit from a supplement, for example with recurring issues, discuss it with your vet.
Not every tub labelled "probiotics" is equally worthwhile. When choosing, look out for the following:
Can I just give my dog or cat probiotics preventively, even without symptoms?
You can, and some owners do this as standard practice during stressful periods. However, evidence that daily preventive use in a healthy animal without symptoms provides measurable benefits is limited. If in doubt, discuss it with your vet.
Can I give plain yoghurt as a natural source of probiotics?
Some dogs tolerate a small amount of plain yoghurt without additives well, but many cats are lactose intolerant and get diarrhoea from it. A pet-specific supplement is a more reliable choice than dairy.
How long before I see an effect?
With mild symptoms, you'll often see improvement within a few days to a week. If there's no improvement, consult your vet.
Is it safe to combine probiotics with a course of antibiotics?
Yes, this is often actively recommended, but ideally give them a few hours apart from the antibiotics, unless your vet advises otherwise.
Do probiotics also help with stress-related behaviour?
Probiotics act on the gut flora, not directly on behaviour. There's growing interest in the so-called gut-brain axis, but for behavioural issues, targeted guidance or training is a more effective approach than a supplement alone.
Probiotics aren't a miracle cure, but in the right situation — a food transition, a course of antibiotics, or a stressful period — they can be a valuable, well-supported way to help your dog's or cat's gut flora. Choose a species-specific supplement with a clearly stated live bacteria count, and always involve a vet if symptoms persist. Not sure which product suits your pet? Your vet or local pet supply store can advise on a species-specific probiotic supplement.