Can cats eat Cat milk / milk replacer?
Yes. Cat milk replacers (Whiskas Catmilk, Lactol Kitten Milk, Royal Canin Babycat Milk) are lactose-reduced or lactose-free and safe for cats as an occasional treat. Not the same as cow's milk.
Key facts
- Verdict: Yes — generally safe for cats in the context described below.
- Category: Dairy
What's the full picture?
Kittens lose most of their lactase (the enzyme that digests lactose) soon after weaning, which is why the majority of adult cats are at least somewhat lactose intolerant. Ordinary cow's milk sits in the gut largely undigested, drawing water in and feeding gut bacteria, which is what causes the classic sloppy stomach and diarrhoea a couple of hours after a cat laps up a saucer of milk. Commercial cat milk gets around this by having the lactose broken down or removed during manufacture, so the finished product doesn't trigger the same reaction in most cats.
In UK supermarkets and pet shops you'll typically find products like Whiskas Catmilk, Felix Milk, and similar own-brand versions sold in small cartons in the pet aisle, usually unrefrigerated until opened. These are aimed at adult and senior cats as a treat, not a meal replacement, and are formulated with cats' actual nutritional needs (and taste preferences) in mind rather than being repurposed dairy for humans.
Kitten milk replacer is a different product with a different job. Brands such as Lactol, Cimicat, and Royal Canin Babycat Milk are designed to substitute for a queen's milk when kittens are orphaned, rejected, or the mother isn't producing enough. These need to be mixed to the correct concentration and fed on a schedule appropriate to the kitten's age — follow the packet instructions exactly, since both over- and under-diluting can cause digestive upset or poor weight gain. Never use ordinary cow's milk or human infant formula as a substitute; neither has the right balance of protein, fat, and calcium for a kitten.
Even lactose-reduced cat milk is a calorie-dense treat rather than a health food. A single small carton can represent a meaningful chunk of a cat's daily calorie allowance, so if you're giving it regularly it's worth accounting for in their overall diet, particularly for cats prone to weight gain or with diabetes. It should never replace fresh drinking water, which cats need available at all times regardless of how much milk they're offered.
We earn commission from some links below (Amazon Associates, Commission Junction, AWIN). This supports the site at no extra cost to you.
Cat owner essentials
For prescription-strength flea, tick and wormer protection, Best Vet Care ships direct from licensed vets — no vet visit required. (affiliate link)
Questions owners ask
Can kittens drink cat milk instead of their mother's milk?
Only if it's specifically labelled as a kitten milk replacer (Lactol, Cimicat, Royal Canin Babycat Milk), not the adult 'cat milk' treat cartons sold for grown cats. Kitten replacers are nutritionally complete for a growing kitten; adult cat milk is not.
Is it safe to give cat milk every day?
In small amounts, yes, but treat it as a treat, not a staple. Daily large servings can contribute to weight gain or, in a minority of cats, still cause loose stools even with the lactose reduced.
What happens if my cat drinks regular cow's milk?
Most adult cats will get diarrhoea and possibly vomiting within a few hours because they can't properly digest the lactose. It's unpleasant rather than dangerous for a healthy adult cat, but repeated exposure isn't worth the stomach upset.
Can I make a homemade lactose-free milk for my cat?
It's simpler and safer to buy a proper commercial cat milk. Plant milks (oat, almond, soya) aren't nutritionally appropriate substitutes and some contain added sugars, flavourings, or xylitol that aren't cat-safe, so they shouldn't be used as a homemade alternative.
UK: For complete daily nutrition, Feline 40 is a cat supplement trusted by 2,600+ UK owners. (affiliate link)US: For premium treats, Granville Island Pet Treatery makes human-grade artisan treats — the premium choice for health-conscious cat owners. (affiliate link)
Recommended for cat owners
Related
Sources referenced for this guidance
- Veterinary Poisons Information Service (VPIS) — UK clinical toxicology reference used by vets
- International Cat Care — feline-specific clinical guidance
- BSAVA — British Small Animal Veterinary Association reference materials
- Merck Veterinary Manual — professional veterinary reference
About this guidance
Every entry on this site is compiled from published UK veterinary toxicology sources — International Cat Care, Veterinary Poisons Information Service (VPIS) references, RCVS-registered practice materials, and peer-reviewed feline medicine literature. Where the evidence is mixed, we err on the cautious side because cats are unusually sensitive to many common substances that are harmless to humans and even to dogs.
This is general information written for UK cat owners. It is not personalised veterinary advice for your specific cat, their age, weight, medical history, or the exact exposure you're dealing with. If your cat has eaten something or is unwell, call your vet first. The Animal PoisonLine on 01202 509000 is available 24/7 for a small fee and can tell you whether an emergency visit is needed.
Entries are reviewed and updated as new research emerges. Spotted an error? Let us know — corrections are investigated and applied within 24 hours. For more context on how we work, see about and our full disclaimer.
Last reviewed: · By the What Can My Cat Eat? editorial team