Sorry I cant help with identification of the plant but I hope your dog is ok, poisoning could show as:

Drinking excessively
Vomiting
Quivering, muscle twitching or fitting
Increased or irregular heart rate
Temperature extremes
Excessive panting
Restlessness

But different poisons cause different parts of the body to be affected so if your dog starts acting in any way to give you concern phone your vet, poisoning is a veterinary emergency. If you do have to call the vet and you can move your dog, take the berries and leaves with you.

For future, it is safer to train your dogs not to eat anything not handed to them or put in their bowl.