Blueberries shouldn't be toxic to cats, but it's not advisable to give them fruit or vegetables frequently.
Cats don't have the same sort of dietary needs as humans do - they don't need to have five pieces of fruit and vegetables everyday to stay healthy!
Instead, cats need a lot of protein in their diets, and this is why the vast majority of their meals are meat.
Some cats will love the taste of things that don't do them any good, such as fruit or vegetables, but this doesn't mean that they should make them a part of their staple diet. However, there is nothing wrong with a treat once in a while!
Cats need plenty of protein in their diets to function, so make sure cat food is their main food source.
Blueberries can be a great treat for your feline friend, but make sure to keep them happy with a lot of meat!