Is spearmint safe for cats

First : Why would you give spearmint to the dog ?

Second : NO it's not.

Spearmint is safe for dogs, so is peppermint. Wintergreen is the mint that dogs CAN'T have. Several companies make dog biscuits that aid in eliminating bad breath which contain spearmint: MilkBone, Booda Bone, etc. Also, there are mint flavored tennis balls for dogs which uses spearmint.