my tiny yorkie attacks the grass in the park and eats it i can not stop him and when he gets home is sick , i am very concerned and want him to stop, i have even bought him a football to distract him although he loves the ball it did not work ,also said a very firm no that did not work, any advice ,and also is this harmful?

I would not worry too much, eating grass is natural, if its excessive I suggest you give your vet a visit to check on any underlying Gastro-intestinal
problems, also I would worm your dog regularly, if he/she is eating grass where other dogs are about doing their business there will be a greater risk of infection.