Do not try to pull out their tongue or move them while the seizure is happening. Know that they may lose control of their bowels and bladder, so grabbing towels for this can be helpful, as well as something to support their head to avoid trauma from thrashing.
If a dog has a seizure, they should be seen by a vet. If the seizure is short (lasting only a minute or two) and a single episode, the vet appointment can wait till normal office hours. Bloodwork is always recommended when a dog has had a seizure.
If the seizure is longer than five minutes or if more than one seizure occurs in a 24-hour period, they should be taken to a vet urgently – this is a medical emergency.
Medications are not always indicated for isolated seizure events but this is something that should be discussed in detail with your vet as each case is unique.