Blueberries are a genuinely good small treat, and the most useful thing this article can do is keep them separate in your head from the berry that isn't. Blueberry and grape sit next to each other in a fruit bowl and could not be further apart on a safety list.
- Yes. Blueberries aren't toxic to dogs or cats, and appear on neither species' list of toxic food ingredients.
- 57 kcal per 100 g, so they are a cheap treat in budget terms - roughly 105 g inside a 10 kg dog's daily allowance.
- Not grapes. Grapes, raisins, currants and sultanas are on the toxic list. Blueberries are not. Don't let the word "berry" blur them.
- Watch the dried-fruit trap. Berry cereals, trail mix and muffins frequently contain raisins or sultanas.
- Frozen ones are harder than fresh, which matters for a small dog.
How many blueberries can a dog have?
Both halves of this sum are published, so the answer is unusually firm.
USDA figures put raw blueberries at 57 kcal per 100 g. The WSAVA Global Nutrition Committee's rule is that treats should always make up less than 10% of daily calorie intake, and should never replace a meal.
The worked example is our arithmetic on a stated assumption, not a WSAVA figure. A moderately active 10 kg dog eating in the region of 600 kcal a day has about 60 kcal for treats, which is roughly 105 g of blueberries. A blueberry weighs somewhere around 1.5 g, so that is in the region of 70 berries - though the berry weight is our estimate, and the gram figure is the one to trust.
Which raises the obvious point: can is not should. Seventy blueberries is what the calorie budget technically permits if blueberries are the only treat your dog gets all day. A sudden bowlful of fruit will still give a lot of dogs loose stool, because it is a large and unfamiliar load of fibre and carbohydrate arriving at once rather than because anything in it is harmful. A dozen berries is a treat. A punnet is a change of diet.
WSAVA's toxic food ingredient list, for dogs and for cats, includes grapes, raisins, currants and sultanas. The MSD Veterinary Manual reports that in dogs, more than one grape or raisin per 4.5 kg of bodyweight may contain enough of the proposed toxic principle to pose a risk, and that the consequence at the severe end is kidney failure. Blueberries carry none of that.
The reason this belongs in a blueberry article is the packet, not the punnet. Dried fruit and cereal mixes are where the two get confused: "berry" granola, trail mix, fruit bars, scones, muffins and bakery items routinely contain raisins or sultanas alongside or instead of blueberries. A dog that has eaten something berry-flavoured out of a packet needs the ingredients read, not a reassurance.
If raisins or sultanas were in it, treat it as a grape exposure and ring your vet now rather than waiting to see what happens.
Fresh, frozen and everything else
- Fresh is the simplest form. Wash them; nothing else needed.
- Frozen are popular in hot weather and work well, but a frozen berry is considerably harder than a fresh one. WSAVA asks that any treat be an appropriate size and shape to reduce the risk of choking - for a small dog, a frozen blueberry is worth squashing or thawing first.
- Dried blueberries concentrate the sugar into a much smaller package, so the same handful is a far bigger calorie load. Read the bag, too: dried fruit blends are exactly where sultanas turn up.
- Blueberry-flavoured anything - yoghurts, muffins, cereal bars, pancakes - is a different food. Some sugar-free products also contain xylitol, which is a genuine emergency for a dog.
Plain berries, on their own. That is the whole method.
Which dogs should go carefully
Blueberries are naturally sugary, which matters for some dogs more than others. WSAVA's standing position applies: if a dog has a medical condition, dietary sensitivities, or is on a veterinary-prescribed diet, conventional treats may not be appropriate at all. Check first if your dog is diabetic, overweight, or on a calorie- or carbohydrate-controlled plan.
Mild digestive upset after too many usually settles on its own. Contact your vet if vomiting or diarrhoea is severe, persistent, bloody, or accompanied by lethargy or abdominal pain.
Can cats eat blueberries?
Not toxic, and mostly ignored. Cats do not perceive sweetness the way we do - the gene for one half of the mammalian sweet-taste receptor is an unexpressed pseudogene in cats, so that receptor never forms - which is why fruit tends to get a sniff and nothing more.
If a cat does want one, the portion is small in a way that is easy to underestimate. WSAVA publishes a daily treat allowance for cats by bodyweight: 22 kcal a day for a 4 kg cat, which is about 39 g of blueberries for the entire day, and that has to cover every other treat too. One or two berries occasionally is not a safety concern. There is no nutritional argument for making it a routine, and for a cat the same size-and-shape caution applies - a whole frozen berry is not an ideal object for a small mouth.
The grape warning applies to cats as well: WSAVA lists grapes, raisins, currants and sultanas among the foods to avoid for cats, not just dogs.
Not sure about something else your pet got into?
Check any food instantly in the Supernormal app's food safety checker - or try the Pet Food Safety Checker for the foods we've covered so far.
Related guides: Pet Food Safety Checker · Can Dogs Eat Grapes or Raisins? · Can Dogs Eat Apples? · Can Dogs Eat Carrots?