1.5 yo toy poodle tremors

Over the past couple of months - maybe once a month my dog has tremors and when he gets bad he loses his balance and is unable to walk. He won’t eat or drink or move around much at all. The next day, he would be back to normal again. He went to the emergency twice because it happened during the night, but bloodwork and tests would come back normal. The vet says everything comes back negative and say that he must’ve picked up weed or something if he gets better over time. I live in a suburban area and now it’s getting real hard to believe that my dog is picking up weed on his walks when he goes on multiple walks per day and he gets sick maybe once or once every other month. Has anybody else experienced this w their dog???
@nietzscheiswrong Veterinary technician here......Try to get some video when he's having one of these episodes to show your vet, ok? Mark them on the calendar also along with the time of day. Has your regular vet seen him for an exam? Did anyone ever mention the possibility of epilepsy to you? Dogs ingesting weed is unfortunately increasing in some areas but it can be tested for to know for sure. If his possible exposure is low, I'd be looking at epilepsy or vascular issues going on. If he's had standard bloodwork done at the ER, you can have those and his records copied for you or sent to your regular vet, ok?
@nietzscheiswrong Vet student here. It’s possible that these episodes are seizures. The tremors and wobbliness plus normal diagnostic tests support this. Try to write down the days it happens, how long it lasts and get a video if possible. Call your vet or another one and ask to discuss it with them. If they are more frequent than every 6 weeks, they may suggest some medications.

When it has only happened once, the main thought is that they have eaten something funny and it was an isolated incident. Twice makes you suspicious of a condition and three times warrants some further investigation.
@nietzscheiswrong Did they check the blood pressure? It's not common for them to do it at a vet. My toy poodle has high blood pressure and was exhibiting similar behavior prior to receiving his bp medication. We're still trying to find the root cause of his high bp, but so far no luck.

They should test it three times after the dog calms down to account for white coat syndrome.