It's not necessary for a dog to eat grain free dog food.
it's okay to feed your dog grain free dog food in moderation but to keep the dog healthy the dog needs grain based dog food.
If you feed your dog strictly grain free dog food then the dog may suffer heart issues, heart disease etc.
Grain free dog food when fed to dogs in moderation or along with grain based dog food will not harm your dog but make sure to feed the dog some dog food that contains grain.
Studies have shown that feeding your dog too much grain free dog food or strictly feeding the dog just grain free dog food can cause life-threatening heart problem called dilated cardiomyopathy, or DCM.
So no grain free dog food is not necessary and could actually do more harm to your dogs health than it would benefit.