IMMEDIATE: FROTHING MOUTH AND SEIZURE IN MY DOG

My dog abruptly started showing signs of a terrible seizure. He's foaming at the mouth and can't stay still. I don't know what to do next. Please help! Is this a sign of something really bad? I'm so scared, he's my best friend. My Dog Is Having a Seizure, Foaming at the Mouth It's incredibly frightening to witness your dog/your pet/my furry fri