Grapes are a fruiting berry of the deciduous woody vines of the botanical genus Vitis.
Grapes can be eaten raw or they can be used for making wine, jam, juice, jelly, grape seed extract, raisins, vinegar, and grape seed oil.
Grapes are a non-climacterictype of fruit, generally occurring in clusters.
So can rabbits eat grapes at all?
Let’s take a look at their nutritional data in particular their calcium, phosphorus, acidic, sodium, fat and fibre content
Grapes, red or green
Nutritional value per 100 g (3.5 oz)
Energy 288 kJ (69 kcal)
Carbohydrates
18.1 g
Sugars 15.48 g
Dietary fiber 0.9 g
Fat 0.16 g
Protein 0.72 g
Vitamins
Thiamine (B1) (6%)0.069 mg
Riboflavin (B2) (6%)0.07 mg
Niacin (B3) (1%)0.188 mg
Pantothenic acid (B5)
(1%)0.05 mg
Vitamin B6 (7%)0.086 mg
Folate (B9) (1%)2 μg
Choline (1%)5.6 mg
Vitamin C (4%)3.2 mg
Vitamin E (1%)0.19 mg
Vitamin K (14%)14.6 μg
Trace metals
Calcium (1%)10 mg
Iron (3%)0.36 mg
Magnesium (2%)7 mg
Manganese (3%)0.071 mg
Phosphorus (3%)20 mg
Potassium (4%)191 mg
Sodium (0%)2 mg
Zinc (1%)0.07 mg
Other constituents
Fluoride
source wikipedia
As you can see grapes contain a little phosphorus, a hint of calcium, a little acid, a hint of fat but to contain a lot of sugar.
This means that rabbits can eat grapes but only one a week at the most as they are just too sweet to have more than that.
Make sure they are seedless grapes as well, as seed grapes may cause chokage.