URGENT: FROTHING MOUTH AND SEIZURE IN MY DOG

My dog abruptly started going through a severe seizure. He's foaming at the mouth and can't stay still. I don't know what to do. Please help! Is this something I should call a vet about immediately? I'm so scared, he's my best friend. I Think My Pet is Having Seizures, Excessive Drool It's incredibly frightening to witness your dog/your pet/my