I got a litter of pups from the local pound to find homes for them. They all tested positive for coccidiosis. All recovered except one had seizures like that. I found him laying in a bunch of pee & poo-it was so sad. He would seize for about a minute then stop & immediately have another. I rushed him to the vet they finally got them stopped. Everyday I wondered if it would happen again. He actually went blind for several days then his site came back. He was fine for about a month. They had ran all kinds of tests charging me $600, everything was negative. He was eating great, playing, even trying to hunch my leg. I went to get him from his first day of house training he looked like he had been in a seizure for awhile. Again poop & pee everywhere, him lying in it & also foaming at the mouth. I rushed him to the vet again-his veins kept collapsing, they couldnt stopthem, so I had him PTS to stop his suffering.
I never got a answer to what was actually the cause. I suppose maybe it was a neurological problem
I hope your baby gets well.