Cats and dogs can get upset tummies resulting in vomiting, diarrhoea or both, for a variety of different reasons. It's important to know the causes, and when to worry.
Tummy upsets in dogs
If your dog is still bright and well, but vomiting occasionally, then withhold food for 24 hours, (or for puppies under 6 months old, only 6 hours) they can have access to water but only a small amounts often so they don't bring it back up again. After 24 hours (or 6 hours for puppies aged under 6 months) they can be fed a bland diet, something like chicken and rice, small amounts fed little and often throughout the day. If vomiting continues or starts again then seek veterinary attention.
After 2-3 days on a bland diet their normal food can be reintroduced gradually. If your dog isn't vomiting but has diarrhoea then there is no need to starve them and a bland diet can be introduced little and often right away.
Tummy upsets in cats
In cats there also can be many reasons for vomiting and diarrhoea. It could be a diet change, parasites, infections, toxins or a medical condition. It’s important to think of the overall health of your cat as if they aren't eating or drinking for 24 hours they can become very ill.
Are they lethargic? Are they on medication that could be affecting them? Are they young and therefore small and likely to be dehydrated quickly? Or if they are older could they have lost weight and may have underlying health problems? If any of these are likely then contact your vet as soon as possible.
If your cat is well and bright and having occasional vomiting and diarrhoea then food can be withheld for 12 hours. (for Kittens up to 4 hours) but water can be available. After this time, a bland protein only diet can be introduced something like plain cooked chicken or white fish and fed little and often. You can also water down the food a little to help with hydration as cats a prone to not drinking. After 2-3 days their usual food can be gradually reintroduced. If your cat continues vomiting or it starts again then seek veterinary attention.
If your cat isn't vomiting but has diarrhoea then there is no need to withhold food.
It’s important to recognise if your pet is unwell, quiet, lethargic or showing signs or dehydration, if they are passing black tar-like faeces, vomiting blood or dark coffee-coloured vomit then you should contact your vet as soon as possible.
Also, for any young puppies and kittens that have had vomiting or diarrhoea longer than 24 hours, you should seek veterinary advice.
Related guides and advice
Keeping your pets cool and safe: Essential tips for hot weather care