Dog seizures HELP!!

My 19 month old Saint Bernard had a bad seizure last night, fell on the floor shaking very bad, foaming at mouth some, lasted about a full minute maybe minute in a half. Today he had a mild one shaking on floor, Some drool lasted maybe a minute. Both times after he acted like he was dizzy and while trying to stand staring at the closed bedroom door. It takes a few minutes befor he can walk right. I posted a pic of the treat and dog food sprinkles he got for the first time the same day, Not sure if it is the cause. Also started purina pro plan like 2 weeks ago not sure if thats the cause. He also went in a room he usually dont go in and im wondering if he got an ibuprofen pill ((1)) dropped on the floor, I dont know that one was dropped but it has happened in the past. Im just trying to think of anything that caused this. He is about 120 to 130 lbs. My questions are. 1. If he got a pill will the seizures stop when its out of his system? 2. And would 1 pill 200mg. be enough to cause seizures in a dog this big? 3. Also if its something like dog food or anything he ate toxic will he stop having seizures when its out of his system? 4. Can smells like Febreze plug ins cause this? The room he got in had one in there, he was in there maybe 30 minutes. 5. Is he suffering durning the seizures?

Happy New Year.   1) Dogs shouldn't be given human pain killers because they are toxic - if ingestion of a pain-killer is known then it is important to call your vet and have them check the dose.  However 2) Seizures would not usually be the presentation I'd associate with this.   3) And if you'll forgive me saying so, it sounds as though you're walking round the house looking for reasons to give yourself to explain the seizure like incidents.  Unfortunately, the causes of seizures are often internal, especially in younger animals.  While toxicity can be a cause, there are also genetic factors and liver disease and sugar levels and brain factors and more. Without doing tests, not even your vet will be able to determine the cause of a seizure.  4) However, it sounds as though these seizures are getting more common and with him only being a youngster, its probably a good idea to consider whether its worth carrying out those tests.  5) Further, if seizures have happened tonight, it's a good idea to call your emergency vet at have your dog triaged properly so that you understand whether and when your St Bernard needs to be seen, and also so that you know what to do if it happens again.  It's natural to worry you've done something wrong when your dog has a seizure, but more often than not, you haven't.   I hope that something there is useful to you and that your St. Bernard has the best possible outcome from here.

NEXT STEP:  Please contact your emergency  vet for triage (that is, to establish how they are doing right now and how urgently they need to be seen).