Can hamsters eat blueberries?

Yes, in small amounts

Yes, in small amounts. Blueberries are safe and most hamsters love them, but they are still sugary fruit, so keep them to an occasional small treat.

Portion: Half a blueberry for a Syrian; a quarter of a blueberry for a dwarf.
How often: Once or twice a week for a Syrian; no more than once every two weeks for a dwarf.
Dwarf hamsters: Campbell's, Winter White, their hybrids and Chinese hamsters are prone to diabetes. Give blueberry only rarely, as a 5 mm (¼ in) taste no more than once every two weeks, or skip fruit and use a low-sugar vegetable such as cucumber as a treat. Roborovskis are less studied, but they are tiny, so keep their portions just as small.
Sugar: 10 g / 100 g

How to serve it

Wash well
Cut in half or quarters
Use fresh or thawed berries with nothing added
Remove any uneaten piece, including from the hoard, within a few hours

Why

Risks. The main concern is sugar: too much fruit can upset a hamster's digestion and lead to weight gain.

Benefits. Contain fibre and plant pigments, and their small size makes it easy to control portions.

Questions owners ask 2

Can hamsters eat dried blueberries?

It is best not to. Drying concentrates the sugar, and vets advise avoiding dried fruit for hamsters.

Are frozen blueberries OK?

Yes, if they are unsweetened and fully thawed to room temperature before feeding.

Blueberries: nutrition per 100 g

Water	84.2 g
Energy	57 kcal
Sugars	10 g
Fat	0.3 g
Protein	0.7 g
Fibre	2.4 g
Calcium	6 mg
Phosphorus	12 mg
Calcium : phosphorus	0.5 : 1
Sodium	1 mg
Vitamin A (RAE)	3 µg
Vitamin C	9.7 mg

“Blueberries, raw”, USDA FoodData Central (SR Legacy, FDC 171711). Public domain.

Sources & method 7

The sources below discuss blueberries for hamsters (or for pet rodents generally). Confidence: high. Rated on the JOMIZOO Feeding Scale; when good sources disagree we choose the more cautious level.