I'm so sorry your little buddy isn't doing well.
I agree with the others, it is definitely
time to get him to the vet, and QUICKLY! Seizures aren't actually all that common in dogs, and it could be anything really...including things you wouldn't think would be all that big a deal, yet can be fatal
for little dogs, such as hypoglycemia (low blood sugar) or dehydration. Please let us know how it goes at the vet, and I'll be keeping your little buddy in my prayers.