CRITICAL: FROTHING MOUTH AND SEIZURE IN MY DOG

My dog suddenly started showing signs of a terrible seizure. He's foaming at the mouth and can't move. I don't know what to do next. Please help! Is this an emergency? 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 furry friend having a seizure.